| Redneck Ricer | 09-23-2003 06:55 PM |
Pics of my Car with the Cage/Belts
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Ok, have some pictures of my car with the cage and belts in. So much fun getting in and out! But I will feel much safer next month at NHIS.
Enjoy :)
p-rex
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039238217558978200535.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039234952935499287006.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039236603743517456171.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039232188503876345057.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039238460740571549632.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039235397101156163903.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039238234613535650193.jpg[/IMG]
Enjoy :)
p-rex
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039238217558978200535.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039234952935499287006.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039236603743517456171.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039232188503876345057.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039238460740571549632.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039235397101156163903.jpg[/IMG]
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039238234613535650193.jpg[/IMG]
| skuttledude | 09-23-2003 09:08 PM |
Very nice! Perfect Track car:)
I take it that this is not your daily driver...
Davis
I take it that this is not your daily driver...
Davis
| Redneck Ricer | 09-23-2003 09:11 PM |
[QUOTE][i]Originally posted by Davis K Powers [/i]
[B]Very nice! Perfect Track car:)
I take it that this is not your daily driver...
Davis [/B][/QUOTE]
well, yes and no.
I drive it a lot, butalso have a Jeep I can drive every day if I want. so I am not forced to drive it ever day :)
but thanks!
P-rex
[B]Very nice! Perfect Track car:)
I take it that this is not your daily driver...
Davis [/B][/QUOTE]
well, yes and no.
I drive it a lot, butalso have a Jeep I can drive every day if I want. so I am not forced to drive it ever day :)
but thanks!
P-rex
| DrBiggly | 09-23-2003 10:31 PM |
Looks nice!
Luckily those seats already have a place for the shoulder belts for the harness... ;)
Luckily those seats already have a place for the shoulder belts for the harness... ;)
| squid_sti | 09-24-2003 12:53 AM |
vs side airbags
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Nice job.
But how do you supose that would interact with
the standard side airbags ?
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039234952935499287006.jpg[/IMG]
But how do you supose that would interact with
the standard side airbags ?
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039234952935499287006.jpg[/IMG]
| Redneck Ricer | 09-24-2003 06:49 AM |
Re: vs side airbags
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[QUOTE][i]Originally posted by squid_sti [/i]
[B]Nice job.
But how do you supose that would interact with
the standard side airbags ?
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039234952935499287006.jpg[/IMG] [/B][/QUOTE]
as you can see, they are not the standard seats, therefore, no sideairbags
[B]Nice job.
But how do you supose that would interact with
the standard side airbags ?
[IMG]http://mediaservice.photoisland.com/auction/Sep/20039234952935499287006.jpg[/IMG] [/B][/QUOTE]
as you can see, they are not the standard seats, therefore, no sideairbags
| elgorey | 09-24-2003 10:10 AM |
looks good!
autopower bolt-in?
did you take out the cross-brace?
and get some padding on those bars! :)
autopower bolt-in?
did you take out the cross-brace?
and get some padding on those bars! :)
| markpaco | 09-24-2003 03:31 PM |
What seat brackets did you use to mount them in? Or are they custom mounts?
| nevr2qk | 09-24-2003 03:35 PM |
That's a sharp looking car, and I'm thrilled to hear you're not afraid to drive it (I'm hopeful NHIS is a road coarse).
I hate to be party-pooper, but I'm going to point a few things out.
[list=1][*]You realize the roll cage significantly increases the chances of head trauma if you're involved in an accident on the street (read: without helmet), right? Don't assume your head can't hit it.[*]You need roll bar padding. (Note: the padding is [b]not[/b] intended to protect your un-helmeted head from injury.)[*]The harness bar on the roll cage is the wrong position (I realize you didn't design it- there's precious few bolt in cages worth a damn out there). It's too low and too far back from the seat. The harnesses should attach within -15^ of horizontal and around 4-6" from the rear of the seat. Belts stretch during a collision, and the more they stretch, the more momentum your body gains before being arrested. Less belt length=less belt stretch. Consider adding a harness bar in the correct position, or lowering the seats.[*]I'm not terribly familiar with Sparco seats, but there should be slot cut under the knee cushion for the sub belt. If not, consider making one. Wrapping the belt around the front of the seat is not ideal; the closer the sub belt is to your crotch the better it can hold the lap belts down.[/list]
Sorry- I know this is the last thing you want to hear, especially after the fact, but the information is intended in goodwill. You're certainly welcome to ignore it.
Brock
I hate to be party-pooper, but I'm going to point a few things out.
[list=1][*]You realize the roll cage significantly increases the chances of head trauma if you're involved in an accident on the street (read: without helmet), right? Don't assume your head can't hit it.[*]You need roll bar padding. (Note: the padding is [b]not[/b] intended to protect your un-helmeted head from injury.)[*]The harness bar on the roll cage is the wrong position (I realize you didn't design it- there's precious few bolt in cages worth a damn out there). It's too low and too far back from the seat. The harnesses should attach within -15^ of horizontal and around 4-6" from the rear of the seat. Belts stretch during a collision, and the more they stretch, the more momentum your body gains before being arrested. Less belt length=less belt stretch. Consider adding a harness bar in the correct position, or lowering the seats.[*]I'm not terribly familiar with Sparco seats, but there should be slot cut under the knee cushion for the sub belt. If not, consider making one. Wrapping the belt around the front of the seat is not ideal; the closer the sub belt is to your crotch the better it can hold the lap belts down.[/list]
Sorry- I know this is the last thing you want to hear, especially after the fact, but the information is intended in goodwill. You're certainly welcome to ignore it.
Brock
| jamz | 09-24-2003 03:49 PM |
In reference to the roll cage padding, you can get some good stuff at HMS Motorsports in Peabody.
Ignore the foam stuff, they wont help your head much, but go for the hard plastic stuff- it's designed to permanently deform in a crash much the same way normal pillar covers are.
Ignore the foam stuff, they wont help your head much, but go for the hard plastic stuff- it's designed to permanently deform in a crash much the same way normal pillar covers are.
| SubaruPartsGirl | 09-24-2003 04:08 PM |
Having the belt come from underneath the seat is defeating the purpose of that portion of the belt.
| Sean | 09-24-2003 04:09 PM |
Also, regarding padding, check out the high density padding ($17 per yard from [url]www.hmsmotorsport.com[/url] in Peabody). The normal foam padding protects your helmet from dings in light impacts like bumps and hard turns where your helmet lightly smacks the bars. But, in an accident, your head will go straight through the padding to the bar if you're not wearing a helmet.
The high density padding feels like hardshell ABS plastic but, when your head smacks it in a hard impact, the foam pops and compresses, making a nice soft cushion that catches your head before it hits the metal bar underneath. In light impacts it feels like your head is bumping against the plastic molding covering the pillars but, trust me, in a real accident there will be less injuries.
[URL=http://www.trunkmonkey.com/][IMG]http://www.trunkmonkey.com/pics/lil.gif[/IMG] Team Updates[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=FAQ&file=index]FAQ[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=News&file=index&catid=6&topic=]NESIC News[/URL] | [url=http://www.trunkmonkey.com/index.php?module=PostCalendar]NESIC Calendar[/url] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=gallery&file=index]Gallery[/URL] | [URL=http://www.trunkmonkey.com/index.php?module=ContentExpress&func=display&ceid=6&bid=20&btitle=Random%20Static&meid=8]Birth[/URL]
The high density padding feels like hardshell ABS plastic but, when your head smacks it in a hard impact, the foam pops and compresses, making a nice soft cushion that catches your head before it hits the metal bar underneath. In light impacts it feels like your head is bumping against the plastic molding covering the pillars but, trust me, in a real accident there will be less injuries.
[URL=http://www.trunkmonkey.com/][IMG]http://www.trunkmonkey.com/pics/lil.gif[/IMG] Team Updates[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=FAQ&file=index]FAQ[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=News&file=index&catid=6&topic=]NESIC News[/URL] | [url=http://www.trunkmonkey.com/index.php?module=PostCalendar]NESIC Calendar[/url] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=gallery&file=index]Gallery[/URL] | [URL=http://www.trunkmonkey.com/index.php?module=ContentExpress&func=display&ceid=6&bid=20&btitle=Random%20Static&meid=8]Birth[/URL]
| Redneck Ricer | 09-24-2003 04:35 PM |
ok, so I guess everyone would rather picture when
a: my seat is in the correct driving position.
b: the high density foam padding is all in place instead of in thr trunk.
c. the belts are properly adjusted and not help in with electrical tape
d. the car is ready to drive...
I wanted to show of pictures of the cage, thats all. I do appreciate all the advice. There is a sub hol ein the Recaro seats, for the sub belt, but the belts are not through it. I do have like 14 yards of padding, but it is not on the car. I will permanately attached the belts, and not leave them taped on :)
thanks fo rthe comments though..
p-rex
a: my seat is in the correct driving position.
b: the high density foam padding is all in place instead of in thr trunk.
c. the belts are properly adjusted and not help in with electrical tape
d. the car is ready to drive...
I wanted to show of pictures of the cage, thats all. I do appreciate all the advice. There is a sub hol ein the Recaro seats, for the sub belt, but the belts are not through it. I do have like 14 yards of padding, but it is not on the car. I will permanately attached the belts, and not leave them taped on :)
thanks fo rthe comments though..
p-rex
| Sean | 09-24-2003 04:46 PM |
No worries. The cage looks sweet...we're just trying to prevent injuries (or educate on the risk of injury). I daily drive my Impreza with a full cage and harnesses. I'm fully aware of the risks of a street accident without a helmet...I'm just an idiot and am willing to take the chance until I get a support/tow vehicle as a daily driver to replace the Impreza. :lol:
Also, high density padding isn't required everywhere...just where your soft bits run the risk of hitting hard bits. I use high density near the head and regular stuff everywhere else. 14 yards seems like overkill...I did my entire cabin with 1.5 yards of high density and 1.5 yards of normal foam.
[URL=http://www.trunkmonkey.com/][IMG]http://www.trunkmonkey.com/pics/lil.gif[/IMG] Team Updates[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=FAQ&file=index]FAQ[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=News&file=index&catid=6&topic=]NESIC News[/URL] | [url=http://www.trunkmonkey.com/index.php?module=PostCalendar]NESIC Calendar[/url] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=gallery&file=index]Gallery[/URL] | [URL=http://www.trunkmonkey.com/index.php?module=ContentExpress&func=display&ceid=6&bid=20&btitle=Random%20Static&meid=8]Birth[/URL]
Also, high density padding isn't required everywhere...just where your soft bits run the risk of hitting hard bits. I use high density near the head and regular stuff everywhere else. 14 yards seems like overkill...I did my entire cabin with 1.5 yards of high density and 1.5 yards of normal foam.
[URL=http://www.trunkmonkey.com/][IMG]http://www.trunkmonkey.com/pics/lil.gif[/IMG] Team Updates[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=FAQ&file=index]FAQ[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=News&file=index&catid=6&topic=]NESIC News[/URL] | [url=http://www.trunkmonkey.com/index.php?module=PostCalendar]NESIC Calendar[/url] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=gallery&file=index]Gallery[/URL] | [URL=http://www.trunkmonkey.com/index.php?module=ContentExpress&func=display&ceid=6&bid=20&btitle=Random%20Static&meid=8]Birth[/URL]
| Penguinking | 09-24-2003 10:03 PM |
can we see pictures of a properly caged and padded car?
| Redneck Ricer | 09-25-2003 12:14 AM |
[QUOTE][i]Originally posted by Penguinking [/i]
[B]can we see pictures of a properly caged and padded car? [/B][/QUOTE]
as soon as I can take them this weekend, I will post them, with the nice pink padding :)
p-rex
[B]can we see pictures of a properly caged and padded car? [/B][/QUOTE]
as soon as I can take them this weekend, I will post them, with the nice pink padding :)
p-rex
| Ver. 8 STi WRB | 09-25-2003 01:04 AM |
NO offense but you should not even be using the "harness bar" you should mount them to the rear brackets in the rear seat for many reasons read my post in the harness thread. Padding is not as important as people would have you think, it is not their fault they are just repeating what they ahve read on the internet. Look at a modern WRC car and see where they have padding and you will notice that they do not use very much. Just some food for thought. Good luck!
| Ver. 8 STi WRB | 09-25-2003 01:10 AM |
You are using recaro SRD's correct??? which does not have the hole for the sub strap (sr3 or sr5 does have them) you should just ditch teh sub belt. Frankly the 5-point is really no more effective then a 4-point (PEr Gary Trammel DR for Champ Cars at a safety seminar) while 6-point is much more effective then either. TO view a properly caged car look at [url]http://www.cascadeautosport.com/rally/preparation.html[/url] they have some good cage pics. You can get a proper pukka pre-fabbed FIA cage for 700-1500 dollars depends on the car. Installed for 2000-2500 depending on how much work you want. if you know the right sources. ;)
| SAW | 09-25-2003 01:14 AM |
I am wondering something.
If you had the proper padding and cage and all that, could you safely have passengers in the back seat if they were wearing helmets?
I don't know anything about rally or road course prep.
Thanks
SAW
If you had the proper padding and cage and all that, could you safely have passengers in the back seat if they were wearing helmets?
I don't know anything about rally or road course prep.
Thanks
SAW
| Redneck Ricer | 09-25-2003 09:00 AM |
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[B]You are using recaro SRD's correct??? which does not have the hole for the sub strap (sr3 or sr5 does have them) you should just ditch teh sub belt. Frankly the 5-point is really no more effective then a 4-point (PEr Gary Trammel DR for Champ Cars at a safety seminar) while 6-point is much more effective then either. TO view a properly caged car look at [url]http://www.cascadeautosport.com/rally/preparation.html[/url] they have some good cage pics. You can get a proper pukka pre-fabbed FIA cage for 700-1500 dollars depends on the car. Installed for 2000-2500 depending on how much work you want. if you know the right sources. ;) [/B][/QUOTE]
[url]http://www.speedwaremotorsports.com/seat/srd.asp[/url]
here you will see you can get the SRD's with or without a sub belt
[B]You are using recaro SRD's correct??? which does not have the hole for the sub strap (sr3 or sr5 does have them) you should just ditch teh sub belt. Frankly the 5-point is really no more effective then a 4-point (PEr Gary Trammel DR for Champ Cars at a safety seminar) while 6-point is much more effective then either. TO view a properly caged car look at [url]http://www.cascadeautosport.com/rally/preparation.html[/url] they have some good cage pics. You can get a proper pukka pre-fabbed FIA cage for 700-1500 dollars depends on the car. Installed for 2000-2500 depending on how much work you want. if you know the right sources. ;) [/B][/QUOTE]
[url]http://www.speedwaremotorsports.com/seat/srd.asp[/url]
here you will see you can get the SRD's with or without a sub belt
| Redneck Ricer | 09-25-2003 09:00 AM |
[QUOTE][i]Originally posted by SAW [/i]
[B]I am wondering something.
If you had the proper padding and cage and all that, could you safely have passengers in the back seat if they were wearing helmets?
I don't know anything about rally or road course prep.
Thanks
SAW [/B][/QUOTE]
no, the backseat is really useless for anything but storage
[B]I am wondering something.
If you had the proper padding and cage and all that, could you safely have passengers in the back seat if they were wearing helmets?
I don't know anything about rally or road course prep.
Thanks
SAW [/B][/QUOTE]
no, the backseat is really useless for anything but storage
| Redneck Ricer | 09-25-2003 09:03 AM |
So I am really confused here.
I have some people telling me I need the belts as close to the seats as possibe, since they stretch.
then I have others telling me I have to hook them up to the back of the car, which would make about 3 feet of slack.
I am open to criticism (constructive of course :)) and suggestions, but it seems that with every bit of advice, there is contradicting advice as well.
I planned on having the cage installed, having the belts on teh harness bars, at correct angles, using the padding I have to pad the bar as I see fit, and make it so it is legal, safe, and will pass tech inspection. If I am doing something wrong that would prevent that, I am more than happy to listen to suggestions..
but...
It is getting hard for me, with all the contradictory info I am recieving.
p-rex
I have some people telling me I need the belts as close to the seats as possibe, since they stretch.
then I have others telling me I have to hook them up to the back of the car, which would make about 3 feet of slack.
I am open to criticism (constructive of course :)) and suggestions, but it seems that with every bit of advice, there is contradicting advice as well.
I planned on having the cage installed, having the belts on teh harness bars, at correct angles, using the padding I have to pad the bar as I see fit, and make it so it is legal, safe, and will pass tech inspection. If I am doing something wrong that would prevent that, I am more than happy to listen to suggestions..
but...
It is getting hard for me, with all the contradictory info I am recieving.
p-rex
| johnfelstead | 09-25-2003 09:32 AM |
The most important thing with harnesses is the angle the belts are running. You want the shoulder belts to be as horizontal as posible, this is to prevent downward loads on your spine and on the seat. Crutch straps are important as they prevent you from submarining into the footwell of the car in a heavy frontal impact. If you roll its the lap belt that holds you, not the shoulder belts.
It's important that you buckle up in the correct sequence, always set your lap belt first so it is hugging you properly, then do the crutch belt, then do the shoulder belts.
Having the belts mounted on a back stay bar is fine, the belts dont stretch enough for that to be an issue as long as you tighten them properly in the correct sequence. If its good enough for Petter Solberg and Tommi Makinen, its good enough for you.
[img]http://www.johnfelstead.co.uk/rally/wrc/monte_carlo_2003/images/DCP04708.JPG[/img]
[img]http://www.johnfelstead.co.uk/rally/wrc/monte_carlo_2002/images/DCP02140.JPG[/img]
However, looking at your pictures, the passenger seat belt angle is very poor indeed, if you have a rear bar to pick up on, use that.
It's important that you buckle up in the correct sequence, always set your lap belt first so it is hugging you properly, then do the crutch belt, then do the shoulder belts.
Having the belts mounted on a back stay bar is fine, the belts dont stretch enough for that to be an issue as long as you tighten them properly in the correct sequence. If its good enough for Petter Solberg and Tommi Makinen, its good enough for you.
[img]http://www.johnfelstead.co.uk/rally/wrc/monte_carlo_2003/images/DCP04708.JPG[/img]
[img]http://www.johnfelstead.co.uk/rally/wrc/monte_carlo_2002/images/DCP02140.JPG[/img]
However, looking at your pictures, the passenger seat belt angle is very poor indeed, if you have a rear bar to pick up on, use that.
| nevr2qk | 09-25-2003 10:21 AM |
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[B]NO offense but you should not even be using the "harness bar" you should mount them to the rear brackets in the rear seat for many reasons read my post in the harness thread. Padding is not as important as people would have you think, it is not their fault they are just repeating what they ahve read on the internet. Look at a modern WRC car and see where they have padding and you will notice that they do not use very much. Just some food for thought. Good luck! [/B][/QUOTE]
Harness bars are used for a reason. Which is easier to to draw tight and keep tight- a 6" length of rope or a 6' length of rope?
This is a street car, not a purpose built racer. Regardless, the padding adds another layer of energy absorption. What idiot wouldn't want that in an accident?
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[B]Frankly the 5-point is really no more effective then a 4-point (PEr Gary Trammel DR for Champ Cars at a safety seminar) while 6-point is much more effective then either.[/B][/QUOTE]
Is it possible you took the lecture out of context?
For a reclined seating seating position (such as a champ car), a 6-point is absolutely necessary. The sub belts wrap around the legs so that your body weight is supported by your hips in a collision.
For sedans (upright seats), it's a completely different story. The "sub" belt is a bit of a misnomer, because you won't slide under the lap belts. Instead, this belt is used to counter the upward pull of the shoulder harnesses; it keeps the lap belts where they belong- on your lap. Without it, the lap belt pulls up across your stomach, and can cause serious internal injuries in a collision.
I've tightened the piss out of 4-point lap belts, and it still rides too high once properly tightening the shoulder belts. For autox, I'm OK with this. For open track, I'll decline a 4-point in favor of the factory 3-point every time.
[QUOTE][i]Originally posted by p-rex [/i]
[B]So I am really confused here.[/B][/QUOTE]
It's no wonder. Harness and cage questions are some of the most commonly asked on enthusiast forums such as this, yet one of the most misunderstood topics. I've regurgitated this information enough that I'm actually going to get off my lazy butt and add a couple of primers to my website.
For more information, [url=http://corner-carvers.com/wiki/index.php?Notes%20on%20Race%20Car%20Harnesses]click here[/url], read the rules / recommendations given in the SCCA GCR, and look up this past summer's issues of SportsCar. They had a really good article (i think it may have been divided between a couple of months) on the safety harness types, applications, the industry FIA regs, and current schools of thought.
I've read more on the topic, but it's going to take me a while to remember where.
Brock
P.S. On preview, I noticed John's post. He has a good point. Tightening the belts in the proper sequence is equally important to proper mounting. I'll go further though, and say it's all equally important. A chain is only as strong as it's weakest link. Inadequate attach points, the wrong shoulder harness angle, to much distance, improper tightening, all serve to undermine the belt's effectiveness.
Additionally, I'd avoid the blanket assumption that just because competition car(s) in a certain santioning body is/are configured a certain way, then that must be adequate for your vehicle and your application. I'll admit I'm not an avid WRC follower, but I haven't seen any concrete retaining walls yet. Blasting down a dirt road is not the same as a road course.
[B]NO offense but you should not even be using the "harness bar" you should mount them to the rear brackets in the rear seat for many reasons read my post in the harness thread. Padding is not as important as people would have you think, it is not their fault they are just repeating what they ahve read on the internet. Look at a modern WRC car and see where they have padding and you will notice that they do not use very much. Just some food for thought. Good luck! [/B][/QUOTE]
Harness bars are used for a reason. Which is easier to to draw tight and keep tight- a 6" length of rope or a 6' length of rope?
This is a street car, not a purpose built racer. Regardless, the padding adds another layer of energy absorption. What idiot wouldn't want that in an accident?
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[B]Frankly the 5-point is really no more effective then a 4-point (PEr Gary Trammel DR for Champ Cars at a safety seminar) while 6-point is much more effective then either.[/B][/QUOTE]
Is it possible you took the lecture out of context?
For a reclined seating seating position (such as a champ car), a 6-point is absolutely necessary. The sub belts wrap around the legs so that your body weight is supported by your hips in a collision.
For sedans (upright seats), it's a completely different story. The "sub" belt is a bit of a misnomer, because you won't slide under the lap belts. Instead, this belt is used to counter the upward pull of the shoulder harnesses; it keeps the lap belts where they belong- on your lap. Without it, the lap belt pulls up across your stomach, and can cause serious internal injuries in a collision.
I've tightened the piss out of 4-point lap belts, and it still rides too high once properly tightening the shoulder belts. For autox, I'm OK with this. For open track, I'll decline a 4-point in favor of the factory 3-point every time.
[QUOTE][i]Originally posted by p-rex [/i]
[B]So I am really confused here.[/B][/QUOTE]
It's no wonder. Harness and cage questions are some of the most commonly asked on enthusiast forums such as this, yet one of the most misunderstood topics. I've regurgitated this information enough that I'm actually going to get off my lazy butt and add a couple of primers to my website.
For more information, [url=http://corner-carvers.com/wiki/index.php?Notes%20on%20Race%20Car%20Harnesses]click here[/url], read the rules / recommendations given in the SCCA GCR, and look up this past summer's issues of SportsCar. They had a really good article (i think it may have been divided between a couple of months) on the safety harness types, applications, the industry FIA regs, and current schools of thought.
I've read more on the topic, but it's going to take me a while to remember where.
Brock
P.S. On preview, I noticed John's post. He has a good point. Tightening the belts in the proper sequence is equally important to proper mounting. I'll go further though, and say it's all equally important. A chain is only as strong as it's weakest link. Inadequate attach points, the wrong shoulder harness angle, to much distance, improper tightening, all serve to undermine the belt's effectiveness.
Additionally, I'd avoid the blanket assumption that just because competition car(s) in a certain santioning body is/are configured a certain way, then that must be adequate for your vehicle and your application. I'll admit I'm not an avid WRC follower, but I haven't seen any concrete retaining walls yet. Blasting down a dirt road is not the same as a road course.
| johnfelstead | 09-25-2003 05:32 PM |
[QUOTE][i]Originally posted by nevr2qk [/i]
[B]I'll admit I'm not an avid WRC follower, but I haven't seen any concrete retaining walls yet. Blasting down a dirt road is not the same as a road course. [/B][/QUOTE]
Correct, road courses are inherantly safer with bariers designed to deflect impact. Rally courses have big trees and big drops that are far more intrusive and move less in an impact. Also rally accidents tend to be multiple impact due to the nature of the road surfaces, general terain and grip levels.
[B]I'll admit I'm not an avid WRC follower, but I haven't seen any concrete retaining walls yet. Blasting down a dirt road is not the same as a road course. [/B][/QUOTE]
Correct, road courses are inherantly safer with bariers designed to deflect impact. Rally courses have big trees and big drops that are far more intrusive and move less in an impact. Also rally accidents tend to be multiple impact due to the nature of the road surfaces, general terain and grip levels.
| Ver. 8 STi WRB | 09-25-2003 05:55 PM |
Did you know that technical regulations for FIA group A (super production) and Group N (production) touring cars are the same as though for Group A rally cars and Group N rally cars. Allow me to clarify a few myths that exist here in the states. Remember that on a race track though you have concrete barriers you also have run-off areas as well as gravel traps. Your car will decelerate before impact. Rally has many different types of impacts the worst being trees and rock walls. Even in a group 2 car with only one liter of displacement we have reached well over 100mph on stage which is similar speeds to circuit racing so saying that what is safe in rally and what is road course safe is not really a valid arguement. One person mentioned that you need the substrap to avoid sliding into the footwell, you are right that this is why we employ a sub strap but it is not as much of an issue in a saloon car as it is in a formula car. The difference is simple physics look at body position in a formula car vs in a saloon you are almos lying down (in modern F1 cars the drivers feet are about the same level as his head. Try it at home sti up in a chair and have a friend push from behind then ry is lying down which way do you subamrine more readily? In general in America (SCCA and NASA) people preach about cage rigidity theus (they have outlawed bolt in cages) but as John will attest many many big teams use bolt in cages. THe other thing that people preach in America is not to use Chromoly tubing and to use really thick mild steel (.120 or 095 wall) while in Europe most teams use FE45, T45 (4130), or CDS tubing 50mm main hoop and the walls are much thinnerthis is so they do not have to trully "normalize" the welds which is impossible unless you havea gigantic oven. When you use thin walled stuf normalization is not really an issue but here we have our own way of doing things. Another common SCCA/NASA arguement is that thin walled tubing is not as safe but what they fail to recognize when you increase outer diameter of a tube the wall can be thinner while actually being much stronger. You want the cage to deform because it absorbs energy yet here people see a cage deforming as a sign of poor design whish is not the case. Did you folks know that this year the SCCA did not require door bars for roll cages which I find absolutely irresponsible. Looking at the door bars on this guys cage they are too low they should extend from the bottom of the window sill to the floor in a diagonal. Whiel there are many opinions the bottom line is that an FIA approved cage has had the design tested and examined by engineers employed by the FIA can your local cage builder say that they have employed engineers to analyze their designs (most of which are blatant FIA copies). This is probably more than most of you ever wanted to know about cages and saftey equipment but I do not take safety lightly and I feel that there is a lot of misinformation on boards and the internet in general. I hope that most of you have understood the points I am trying to make which is safety is an engineered thing that must be thought out, you cannot just welld in a ton of bars or mount seatbelts any which way there is a logic to why people do things the way they do them and if used incorrectly they make a vehicle more dangerous then without them. if anyone ever has some cage or ally questions feel free to email me I am always willing to help people with cages, and harness questions. Nevr2qk you make a lot of good points in you post though assuming that road racing and rallying do not have similar levels of safety is a misconception (rally guys and roadrace guys generall yhave different schools of thought), the lecture by dr. trammel was about all safety and alot of it was geared to NASCAR guys (I beleive that they race saloons) but you are correct about the belt being pulled up though what they found was that the 5-point was not really anymore effective then properly utilized 4-points while 6-points were significantly more effective. Having bounced off more then roll cage in my life I will tell you that most of that padding is totally worthless in preventing injuries. YO uwill notice the only one on most cars being rallied in europe have only near the head becaause when used in concert with a helet is is sucssful but exposed limbs do not fair well with metal tubes no matter what is wrapped around them. Whatever makes you feel more comfortable though.
| nevr2qk | 09-25-2003 06:26 PM |
Well, true, road courses employ several barriers designed to absorb energy during an impact, but I'll disagree that they are inherently "safer". A concrete barrier will not give any more than the largest tree.
The point was, that each course offers it's own dangers. From what I've seen many Rally incidences are rollovers or side impacts as the vehicle slides off the road. I see a larger number of frontal impacts (with either other vehicles or barriers) at track events. Rollovers and side impacts don't stress the belts nearly as much- they simply have to hold you in place and while seat assists. It's during head-on impacts that the belts see the high-g loading where belt stretch is much more significant a problem.
I'm not saying rally is safer- I'm saying it may not be an accurate reference point for open track applications. Besides (although this is true of many motorsports), haven't the deadliest recent rally accidents been frontal collisions? Perhaps we'll eventually see some changes in the safety regs.
8 STi WRB- If you'd like to reformat your post so that it's readable, I'll respond.
Brock
[i]edit: fine. i'll be nice.[/i]
The point was, that each course offers it's own dangers. From what I've seen many Rally incidences are rollovers or side impacts as the vehicle slides off the road. I see a larger number of frontal impacts (with either other vehicles or barriers) at track events. Rollovers and side impacts don't stress the belts nearly as much- they simply have to hold you in place and while seat assists. It's during head-on impacts that the belts see the high-g loading where belt stretch is much more significant a problem.
I'm not saying rally is safer- I'm saying it may not be an accurate reference point for open track applications. Besides (although this is true of many motorsports), haven't the deadliest recent rally accidents been frontal collisions? Perhaps we'll eventually see some changes in the safety regs.
8 STi WRB- If you'd like to reformat your post so that it's readable, I'll respond.
Brock
[i]edit: fine. i'll be nice.[/i]
| johnfelstead | 09-25-2003 07:03 PM |
[QUOTE][i]Originally posted by nevr2qk [/i]
[B] Besides (although this is true of many motorsports), haven't the deadliest recent rally accidents been frontal collisions? Perhaps we'll eventually see some changes in the safety regs.
8 STi WRB- If you'd like to reformat your post so that it's readable, I'll respond. Otherwise, it's not worth my time. Sorry, but if you haven't grasped 6th grade grammar, I sincerely doubt you're capable of understanding the physics involved here.
Brock [/B][/QUOTE]
You, sir, are incredibly rude to a contributor who made a worthwhile post of information.
The most dangerous impacts are side impacts in any form of motorsport. We sadly lost Mark and Roger to a side impact into a tree followed by another side impact into a ditch. Colin McRae had a serious crash last year where the cage deformed and crushed his finger, that was a side impact. Frontal/rear impacts are less damaging as you have a larger area to absorb impacts. To a certain extent you will never reach total safety in side impacts, due to space limitations and the ability of the human body to accept loads from a side impact.
[B] Besides (although this is true of many motorsports), haven't the deadliest recent rally accidents been frontal collisions? Perhaps we'll eventually see some changes in the safety regs.
8 STi WRB- If you'd like to reformat your post so that it's readable, I'll respond. Otherwise, it's not worth my time. Sorry, but if you haven't grasped 6th grade grammar, I sincerely doubt you're capable of understanding the physics involved here.
Brock [/B][/QUOTE]
You, sir, are incredibly rude to a contributor who made a worthwhile post of information.
The most dangerous impacts are side impacts in any form of motorsport. We sadly lost Mark and Roger to a side impact into a tree followed by another side impact into a ditch. Colin McRae had a serious crash last year where the cage deformed and crushed his finger, that was a side impact. Frontal/rear impacts are less damaging as you have a larger area to absorb impacts. To a certain extent you will never reach total safety in side impacts, due to space limitations and the ability of the human body to accept loads from a side impact.
| Ver. 8 STi WRB | 09-25-2003 07:32 PM |
Nevr2qk you cannot answer my ponts with a valid arguement so you have to attack my grammar? To respond that there is less stress on the belts in a "roll-over accident" that they "only have to hod you in" you sir are absolutely incorrect. Belts endure a lot of stress where there is any type of secondary impact ie rolling over since the belts stretch with the initial impact then stretch again with the secondary impact. Frontal and rear impacts usually involve a single impact at which a car comes to rest thus the belts only stretch once. Yes road courses and rallying are different but to say that the safety principles are totally different would just plain be irresponsible. Since we are getting into all of the points about this we should mention that all harness belts are photo-sensitive (a concept I should hardly understand due to my 6th grade grammar) and will be affected by sunlight and thus no one whould park their cars outside where the harnesses can see daylight in case they may become brittle.
John you are correct it is the side impacts that are the most dangerous, especially with a rearword rotation (Roger and Mar). An accident similar to that was Peter Wokum and Claire Chizma at LSPR or Maine (cannot remember which) in which they started to spin and made impact in the rear drivers-side door which really hurt both drive and co-driver. A more recent example is Latvala's accident on the Jim Clark where he made a side impact with a huge stone gate and broke his co-driver's hip. IF you watched a recent episode of motorsport mundial you would have noticed that the MG which hit the same gate head-on at high speed also yet neither driver nor co-driver had any injuries.
p-rex I do not kow where you are located but if you are considering any type of cage I suggest that you talk to a local race shop and allow them to give you guidance on your project. Frankly the internet and these boards have so much misinformation that the do-it-yoursefler cannot get an accurate barometer of whether he or she is taking the correct course of action. I would tell you to contact :
[url]www.cascadeautosport.com[/url]
[url]www.vermontsportscar.com[/url]
[url]www.tatomotorsports.com[/url]
[url]http://www.tadmotorsports.com/[/url]
that is a northwest, midwest, east coast, and socal reference of rally shops. Remember safety does not always have to high dollar many companies offer pre-fabbed cages that are FIA homologated (this means you will never have a problem with your local scutineer just hand him or her the homologation paper and you are done) for reasonable prices sparco for GC8 $800, Custom Cages GDB 1000, Prodrive for GC8 or GDB 1500-2300, Safety devices 700-1500). Remember that unfortunately the SCCA changes cage rules frequently so tha building a conforming cage today does not ensure that it will pass tech later in the year yet eht FIA keep cage rules very stable. Good luck with your project call one of the shops I listed and they can really help you.
John you are correct it is the side impacts that are the most dangerous, especially with a rearword rotation (Roger and Mar). An accident similar to that was Peter Wokum and Claire Chizma at LSPR or Maine (cannot remember which) in which they started to spin and made impact in the rear drivers-side door which really hurt both drive and co-driver. A more recent example is Latvala's accident on the Jim Clark where he made a side impact with a huge stone gate and broke his co-driver's hip. IF you watched a recent episode of motorsport mundial you would have noticed that the MG which hit the same gate head-on at high speed also yet neither driver nor co-driver had any injuries.
p-rex I do not kow where you are located but if you are considering any type of cage I suggest that you talk to a local race shop and allow them to give you guidance on your project. Frankly the internet and these boards have so much misinformation that the do-it-yoursefler cannot get an accurate barometer of whether he or she is taking the correct course of action. I would tell you to contact :
[url]www.cascadeautosport.com[/url]
[url]www.vermontsportscar.com[/url]
[url]www.tatomotorsports.com[/url]
[url]http://www.tadmotorsports.com/[/url]
that is a northwest, midwest, east coast, and socal reference of rally shops. Remember safety does not always have to high dollar many companies offer pre-fabbed cages that are FIA homologated (this means you will never have a problem with your local scutineer just hand him or her the homologation paper and you are done) for reasonable prices sparco for GC8 $800, Custom Cages GDB 1000, Prodrive for GC8 or GDB 1500-2300, Safety devices 700-1500). Remember that unfortunately the SCCA changes cage rules frequently so tha building a conforming cage today does not ensure that it will pass tech later in the year yet eht FIA keep cage rules very stable. Good luck with your project call one of the shops I listed and they can really help you.
| nevr2qk | 09-25-2003 07:32 PM |
[QUOTE][i]Originally posted by johnfelstead [/i]
[B]You, sir, are incredibly rude to a contributor who made a worthwhile post of information.[/B][/QUOTE]
You're right- it was rude. I guess I'm just used to playing with a rougher crowd, and I have removed the affront. However, since I couldn't read it, I'm not sure how worthwhile it was.
[QUOTE][i]Originally posted by johnfelstead [/i]
The most dangerous impacts are side impacts in any form of motorsport. We sadly lost Mark and Roger to a side impact into a tree followed by another side impact into a ditch. Colin McRae had a serious crash last year where the cage deformed and crushed his finger, that was a side impact. Frontal/rear impacts are less damaging as you have a larger area to absorb impacts. To a certain extent you will never reach total safety in side impacts, due to space limitations and the ability of the human body to accept loads from a side impact. [/B][/QUOTE]
You're right on this account, too. It occurred to me right after posting that I had confused the load imposed on the belts with the overall severity of the crash. I was in a rush. The shoulder harnesses in question are loaded highest in a frontal collision, however, and that's the point at hand
Brock
[B]You, sir, are incredibly rude to a contributor who made a worthwhile post of information.[/B][/QUOTE]
You're right- it was rude. I guess I'm just used to playing with a rougher crowd, and I have removed the affront. However, since I couldn't read it, I'm not sure how worthwhile it was.
[QUOTE][i]Originally posted by johnfelstead [/i]
The most dangerous impacts are side impacts in any form of motorsport. We sadly lost Mark and Roger to a side impact into a tree followed by another side impact into a ditch. Colin McRae had a serious crash last year where the cage deformed and crushed his finger, that was a side impact. Frontal/rear impacts are less damaging as you have a larger area to absorb impacts. To a certain extent you will never reach total safety in side impacts, due to space limitations and the ability of the human body to accept loads from a side impact. [/B][/QUOTE]
You're right on this account, too. It occurred to me right after posting that I had confused the load imposed on the belts with the overall severity of the crash. I was in a rush. The shoulder harnesses in question are loaded highest in a frontal collision, however, and that's the point at hand
Brock
| johnfelstead | 09-25-2003 07:58 PM |
The reference to Latvala's crash at Jim Clarke has me thinking. Are modern rally cars being designed with codriver safety severely compromised?
Its seems to me, that Co-Driver broken hips is becoming more and more common. I have been around the sport for 20 years and its only the last 2-3 years i have noticed this type of injury ocuring, i dont recall it as common prior to this.
Could this be because Co-Driver seats are now being mounted so low and rearward, that they are in the crush zone from a side impact? With a seat mounted on a higher mount, the mount will distort/break forcing the seat upwards if it will move at all. Low down with no ability to distort, its going to be crushed sideways, so will be squashed between the centre tunnel and the centre outer pillar of the cage or its lower sill area.
I have never thought about this before, picturing it in my mind i can see how there would be more danger to the pelvic area with a floor mounted seat.
Its seems to me, that Co-Driver broken hips is becoming more and more common. I have been around the sport for 20 years and its only the last 2-3 years i have noticed this type of injury ocuring, i dont recall it as common prior to this.
Could this be because Co-Driver seats are now being mounted so low and rearward, that they are in the crush zone from a side impact? With a seat mounted on a higher mount, the mount will distort/break forcing the seat upwards if it will move at all. Low down with no ability to distort, its going to be crushed sideways, so will be squashed between the centre tunnel and the centre outer pillar of the cage or its lower sill area.
I have never thought about this before, picturing it in my mind i can see how there would be more danger to the pelvic area with a floor mounted seat.
| nevr2qk | 09-25-2003 08:03 PM |
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[B]Nevr2qk you cannot answer my ponts with a valid arguement so you have to attack my grammar?[/B][/QUOTE]
It's not a matter ability, but of willingness. I saw several things before I gave up trying to read it. I don't want to spend my time deciphering what you wrote. Would you?
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
To respond that there is less stress on the belts in a "roll-over accident" that they "only have to hod you in" you sir are absolutely incorrect. Belts endure a lot of stress where there is any type of secondary impact ie rolling over since the belts stretch with the initial impact then stretch again with the secondary impact. Frontal and rear impacts usually involve a single impact at which a car comes to rest thus the belts only stretch once.[/B][/QUOTE]
I don't believe you understand the point. Belt stretch is a factor of length and load. The farther the belt stretches, the more momentum your body attains before it is arrested by the belt. It's this sudden stop that causes injury. Are you familiar with kinetics? The higher the momentum, the higher the impulse load on the body. The peak load on belts is typically lower in a rollover (unless of course you immediately hit something).
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
Yes road courses and rallying are different but to say that the safety principles are totally different would just plain be irresponsible. Since we are getting into all of the points about this we should mention that all harness belts are photo-sensitive (a concept I should hardly understand due to my 6th grade grammar) and will be affected by sunlight and thus no one whould park their cars outside where the harnesses can see daylight in case they may become brittle. [/B][/QUOTE]
Yes, all, or almost all, polyesters are photo sensitive. What is your point? Safety harnesses are expendable items intended to be rotated out of service just like, oil, rotors, brake pads, and a number of other items. What does this have to do with installation?
Brock
[B]Nevr2qk you cannot answer my ponts with a valid arguement so you have to attack my grammar?[/B][/QUOTE]
It's not a matter ability, but of willingness. I saw several things before I gave up trying to read it. I don't want to spend my time deciphering what you wrote. Would you?
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
To respond that there is less stress on the belts in a "roll-over accident" that they "only have to hod you in" you sir are absolutely incorrect. Belts endure a lot of stress where there is any type of secondary impact ie rolling over since the belts stretch with the initial impact then stretch again with the secondary impact. Frontal and rear impacts usually involve a single impact at which a car comes to rest thus the belts only stretch once.[/B][/QUOTE]
I don't believe you understand the point. Belt stretch is a factor of length and load. The farther the belt stretches, the more momentum your body attains before it is arrested by the belt. It's this sudden stop that causes injury. Are you familiar with kinetics? The higher the momentum, the higher the impulse load on the body. The peak load on belts is typically lower in a rollover (unless of course you immediately hit something).
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
Yes road courses and rallying are different but to say that the safety principles are totally different would just plain be irresponsible. Since we are getting into all of the points about this we should mention that all harness belts are photo-sensitive (a concept I should hardly understand due to my 6th grade grammar) and will be affected by sunlight and thus no one whould park their cars outside where the harnesses can see daylight in case they may become brittle. [/B][/QUOTE]
Yes, all, or almost all, polyesters are photo sensitive. What is your point? Safety harnesses are expendable items intended to be rotated out of service just like, oil, rotors, brake pads, and a number of other items. What does this have to do with installation?
Brock
| johnfelstead | 09-25-2003 08:06 PM |
Brock, i prescribe decaf for the next week. :o:D
| johnfelstead | 09-25-2003 08:13 PM |
[QUOTE][i]Originally posted by nevr2qk [/i]
[B]
The farther the belt stretches, the more momentum your body attains before it is arrested by the belt. [/B][/QUOTE]
Nope, sorry but that isnt true at all. You are trying to re-write the laws of physics with that one. On impact your body has a set momentum, that will not increase as your body travels as you are not putting any more energy into your body.
You actually want some strech because if you arrest your body to quickly, your internal organs will be bruised as they slam against your ribcage. This is why so much work is going into foam padding materials, to arest movement over an aceptable timeframe, rather than instantaneously.
Its a compromise, you dont want a solid material holding you in place, but you also dont want bungee cord. It's also very important you have your belts tight, as if they arent tight you get a shock load against you on initial impact, plus you could move so much you hit something solid.
[B]
The farther the belt stretches, the more momentum your body attains before it is arrested by the belt. [/B][/QUOTE]
Nope, sorry but that isnt true at all. You are trying to re-write the laws of physics with that one. On impact your body has a set momentum, that will not increase as your body travels as you are not putting any more energy into your body.
You actually want some strech because if you arrest your body to quickly, your internal organs will be bruised as they slam against your ribcage. This is why so much work is going into foam padding materials, to arest movement over an aceptable timeframe, rather than instantaneously.
Its a compromise, you dont want a solid material holding you in place, but you also dont want bungee cord. It's also very important you have your belts tight, as if they arent tight you get a shock load against you on initial impact, plus you could move so much you hit something solid.
| Ver. 8 STi WRB | 09-25-2003 09:15 PM |
Brock allow me to help yo uunderstand how g-forces really work.
Please follow this link:
[url]http://www.npl.co.uk/force/faqs/gforces.html[/url]
Look atthe bottom in grey text where it says that
"on 13_July 1977 British racing driver David Purley survived a deceleration from 173_km/h to zero in a distance of about 0.66_m, enduring 180_g "
We are talking about this sort of force you see that the most important number there is the fact that he decelerated in .66m. G-force is a factor of speed but in motor racing accidents it is more often used to express how quickly an object stops moving. It is the distance in which the deceleration takes place that trully measures the g-force. In many fatal accidents drivers were not traveling very fast (under 45 mph) but they hit either a tree or other immovable objects that caused a rapid deceleration. The most common cause of death in these situations is a Basal Skull fracture that either pinches or severes the brain stem (the portion of the brain that regulates respiration, and heart contractions). Now how does this relate to motor racing you ask?? Well when you have a Basal Skull fracture you have the head and torso moving at different speeds. When an impact occurs the head and torso are both travelling at the same rate of speed, at the impact the belts cinch up and stop the body from moving thus rapidly decelerating the torso while the skull having no restraint continues travelling at the same rate of speed. These differences in speed (or velocity if you like) come together with horrible effects at the base of the skull where it attaches to the spine. When the spine runs out of travel and skull still has not be decelerated you get a basal skull fractures I have seen literally hundreds of them. Now the second part of this is the fact that while our bodies are solid our organs are floting within the abdomen as well as the brain. Same basic principles as the basal skull fracture here; you suddenly decelerate the body and the organs (including the brain) continue to travel until the hit the ribcage or the inner part of the skull at which point your internal organs (and brain) experience a high g impact which can cause a lot of damage. Now that we have the physics out of the way we will address the belt issue. We have a coule of factors with the belts stretching. Stretch too much and you hit your head and everything else against everything, stretch too little and you have too many g forces on the body. THe reasonable arguement is to design so that the belts stretch some but not too much thus the best of both worlds.
Now Bock are you familiar with kinetics? Apparently not since you are trying to re-write the laws of physics. Like John posted at the point of impact your body has a set momentum. In any multiple impact accident you will have real stetching issues since the belts will endure several different impacts (for examplea roll over where belts don't stretch the just "hold you in"). I think that you should use chains instead of belts Brock since that way they will not stretch at all.
:lol:
Please follow this link:
[url]http://www.npl.co.uk/force/faqs/gforces.html[/url]
Look atthe bottom in grey text where it says that
"on 13_July 1977 British racing driver David Purley survived a deceleration from 173_km/h to zero in a distance of about 0.66_m, enduring 180_g "
We are talking about this sort of force you see that the most important number there is the fact that he decelerated in .66m. G-force is a factor of speed but in motor racing accidents it is more often used to express how quickly an object stops moving. It is the distance in which the deceleration takes place that trully measures the g-force. In many fatal accidents drivers were not traveling very fast (under 45 mph) but they hit either a tree or other immovable objects that caused a rapid deceleration. The most common cause of death in these situations is a Basal Skull fracture that either pinches or severes the brain stem (the portion of the brain that regulates respiration, and heart contractions). Now how does this relate to motor racing you ask?? Well when you have a Basal Skull fracture you have the head and torso moving at different speeds. When an impact occurs the head and torso are both travelling at the same rate of speed, at the impact the belts cinch up and stop the body from moving thus rapidly decelerating the torso while the skull having no restraint continues travelling at the same rate of speed. These differences in speed (or velocity if you like) come together with horrible effects at the base of the skull where it attaches to the spine. When the spine runs out of travel and skull still has not be decelerated you get a basal skull fractures I have seen literally hundreds of them. Now the second part of this is the fact that while our bodies are solid our organs are floting within the abdomen as well as the brain. Same basic principles as the basal skull fracture here; you suddenly decelerate the body and the organs (including the brain) continue to travel until the hit the ribcage or the inner part of the skull at which point your internal organs (and brain) experience a high g impact which can cause a lot of damage. Now that we have the physics out of the way we will address the belt issue. We have a coule of factors with the belts stretching. Stretch too much and you hit your head and everything else against everything, stretch too little and you have too many g forces on the body. THe reasonable arguement is to design so that the belts stretch some but not too much thus the best of both worlds.
Now Bock are you familiar with kinetics? Apparently not since you are trying to re-write the laws of physics. Like John posted at the point of impact your body has a set momentum. In any multiple impact accident you will have real stetching issues since the belts will endure several different impacts (for examplea roll over where belts don't stretch the just "hold you in"). I think that you should use chains instead of belts Brock since that way they will not stretch at all.
:lol:
| elgorey | 09-26-2003 09:37 AM |
I didnt realize that we had similar discussions going on in 2 threads. Everyone here should also check out the "dont skimp on your rollcage" thread.
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[BIn general in America (SCCA and NASA) people preach about cage rigidity theus (they have outlawed bolt in cages) [/quote]
nope. bolt-in cages fully legal in SCCA and NASA. Saw at least 15 of them at the last race I was at.
[quote]THe other thing that people preach in America is not to use Chromoly tubing and to use really thick mild steel (.120 or 095 wall) while in Europe most teams use FE45, T45 (4130), or CDS tubing 50mm main hoop and the walls are much [/quote]
Cromoly tubing should not be used because it does not absorb impact as well as mild steel. You said yourself "You want the cage to deform because it absorbs energy" so you should know why this is not good, and why chromo should not be used. The same reason was attributed to many deaths using aluminum cages, and their subsequent outlaw.
[quote]Did you folks know that this year the SCCA did not require door bars for roll cages which I find absolutely irresponsible.[/quote] Maybe you are talking about rallying, because club and pro racing have required them for a long time.
[quote] Whiel there are many opinions the bottom line is that an FIA approved cage has had the design tested and examined by engineers employed by the FIA can your local cage builder say that they have employed engineers to analyze their designs [/quote]
FIA certified cages are an absolute joke. period. case and point: this cage is FIA certified
[img]http://www.we-todd-did-racing.com/wetoddimage.wtdr/i=wMTI3ODAyNnM0MTNkZmQzMXk1NDE%3D[/img]
by the way, Ver 8 sti, please use the enter key. your posts are extremely hard to read.
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[BIn general in America (SCCA and NASA) people preach about cage rigidity theus (they have outlawed bolt in cages) [/quote]
nope. bolt-in cages fully legal in SCCA and NASA. Saw at least 15 of them at the last race I was at.
[quote]THe other thing that people preach in America is not to use Chromoly tubing and to use really thick mild steel (.120 or 095 wall) while in Europe most teams use FE45, T45 (4130), or CDS tubing 50mm main hoop and the walls are much [/quote]
Cromoly tubing should not be used because it does not absorb impact as well as mild steel. You said yourself "You want the cage to deform because it absorbs energy" so you should know why this is not good, and why chromo should not be used. The same reason was attributed to many deaths using aluminum cages, and their subsequent outlaw.
[quote]Did you folks know that this year the SCCA did not require door bars for roll cages which I find absolutely irresponsible.[/quote] Maybe you are talking about rallying, because club and pro racing have required them for a long time.
[quote] Whiel there are many opinions the bottom line is that an FIA approved cage has had the design tested and examined by engineers employed by the FIA can your local cage builder say that they have employed engineers to analyze their designs [/quote]
FIA certified cages are an absolute joke. period. case and point: this cage is FIA certified
[img]http://www.we-todd-did-racing.com/wetoddimage.wtdr/i=wMTI3ODAyNnM0MTNkZmQzMXk1NDE%3D[/img]
by the way, Ver 8 sti, please use the enter key. your posts are extremely hard to read.
| Ver. 8 STi WRB | 09-26-2003 01:02 PM |
Bolt in cages are now illegal old cages that were of bolt in design are still legal.
CHromoly does not absorb energy as well as mild steel??? Sorry but it is not greater riggidity but rather weight savings the reason that people use chromoly. You are completely wrong here, majority of US cage builders do not use Chromoly because they cannot weld it properly because you have to normalize the welds. It has nothing to do with energy absorption.
Look at last years cage rules there is not door bar requirement in SCCA prorally. People weld them in because they are not idiots, would trust a sanctioning body that does not require door bars for rally?
FIA homologated cages are a joke? YEs like many americans you point to some bolt in cage but just because it is FIA homologated does not mean that it is homologated for every application. Every WRC and touring car in ALMS, all the Rally raid cars use FIA homologated cages so I guess that Ralliart, PRodrive, Porsche, and others are foolish. At least the cage you show is close to body unlike a lot of auto pwer cages that people employ. Got to trunkmonkey racing if you wan to see a perfect example of an american engineered cage that illustrates that people do not know what they are doing. Look at that cage if you want see how not to build a cage.
CHromoly does not absorb energy as well as mild steel??? Sorry but it is not greater riggidity but rather weight savings the reason that people use chromoly. You are completely wrong here, majority of US cage builders do not use Chromoly because they cannot weld it properly because you have to normalize the welds. It has nothing to do with energy absorption.
Look at last years cage rules there is not door bar requirement in SCCA prorally. People weld them in because they are not idiots, would trust a sanctioning body that does not require door bars for rally?
FIA homologated cages are a joke? YEs like many americans you point to some bolt in cage but just because it is FIA homologated does not mean that it is homologated for every application. Every WRC and touring car in ALMS, all the Rally raid cars use FIA homologated cages so I guess that Ralliart, PRodrive, Porsche, and others are foolish. At least the cage you show is close to body unlike a lot of auto pwer cages that people employ. Got to trunkmonkey racing if you wan to see a perfect example of an american engineered cage that illustrates that people do not know what they are doing. Look at that cage if you want see how not to build a cage.
| Sean | 09-26-2003 01:25 PM |
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[B]Got to trunkmonkey racing if you wan to see a perfect example of an american engineered cage that illustrates that people do not know what they are doing. Look at that cage if you want see how not to build a cage.[/B][/QUOTE]
Out of curiosity, can you give me some specifics? I realize that the door bars are low but, since the car is currently a daily driver, that was a decision that we made. Once the car moves from daily driver to dedicated rally car we'll be getting another cross welded in and tied down.
For the rest of the cage, the entire cage is less than a half inch away from all surfaces (roof, pillars, etc.) and was designed by Brent Hatch and Tim O'Neil ( [url]www.teamoneil.com[/url] ). Brent has been building rally cages for years and fabricated quite a few cages for local teams as well as all of Tim's cages and all the cages for the Team O'Neil Rally School cars.
With the exception of the low door bars, every single person who has looked at my cage has said that it's an amazing design bordering on overkill.
[URL=http://www.trunkmonkey.com/][IMG]http://www.trunkmonkey.com/pics/lil.gif[/IMG] Team Updates[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=FAQ&file=index]FAQ[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=News&file=index&catid=6&topic=]NESIC News[/URL] | [url=http://www.trunkmonkey.com/index.php?module=PostCalendar]NESIC Calendar[/url] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=gallery&file=index]Gallery[/URL] | [URL=http://www.trunkmonkey.com/index.php?module=ContentExpress&func=display&ceid=6&bid=20&btitle=Random%20Static&meid=8]Birth[/URL]
[B]Got to trunkmonkey racing if you wan to see a perfect example of an american engineered cage that illustrates that people do not know what they are doing. Look at that cage if you want see how not to build a cage.[/B][/QUOTE]
Out of curiosity, can you give me some specifics? I realize that the door bars are low but, since the car is currently a daily driver, that was a decision that we made. Once the car moves from daily driver to dedicated rally car we'll be getting another cross welded in and tied down.
For the rest of the cage, the entire cage is less than a half inch away from all surfaces (roof, pillars, etc.) and was designed by Brent Hatch and Tim O'Neil ( [url]www.teamoneil.com[/url] ). Brent has been building rally cages for years and fabricated quite a few cages for local teams as well as all of Tim's cages and all the cages for the Team O'Neil Rally School cars.
With the exception of the low door bars, every single person who has looked at my cage has said that it's an amazing design bordering on overkill.
[URL=http://www.trunkmonkey.com/][IMG]http://www.trunkmonkey.com/pics/lil.gif[/IMG] Team Updates[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=FAQ&file=index]FAQ[/URL] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=News&file=index&catid=6&topic=]NESIC News[/URL] | [url=http://www.trunkmonkey.com/index.php?module=PostCalendar]NESIC Calendar[/url] | [URL=http://www.trunkmonkey.com/modules.php?op=modload&name=gallery&file=index]Gallery[/URL] | [URL=http://www.trunkmonkey.com/index.php?module=ContentExpress&func=display&ceid=6&bid=20&btitle=Random%20Static&meid=8]Birth[/URL]
| elgorey | 09-26-2003 01:39 PM |
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[B]Bolt in cages are now illegal old cages that were of bolt in design are still legal. [/quote]
Not in road racing. Bolt in still legal.
[quote]CHromoly does not absorb energy as well as mild steel??? Sorry but it is not greater riggidity but rather weight savings the reason that people use chromoly. You are completely wrong here[/quote]
You are completely wrong. I will restate what I just said. CroMoly has a higher rigitidy than mild steel. I will pull out some metals books and reference the specific properties if you still dont believe me.
And as a trained and certified welder (although not my dayjob), ChroMo does not require "normalization" or whatever this garbage you speak of.
[quote]Look at last years cage rules there is not door bar requirement in SCCA prorally. People weld them in because they are not idiots, would trust a sanctioning body that does not require door bars for rally?[/quote]
Now you are just bashing SCCA? I made no claims about SCCAs superiority, and dont give a rats ass. FWIW, I definately wouldnt trust a sanctioning body that approves the above Cusco cage and lets you mount your harnesses 3 feet behind the seat.
[quote]FIA homologated cages are a joke? YEs [/quote]
[quote]Whiel there are many opinions the bottom line is that an FIA approved cage has had the design tested and examined by engineers employed by the FIA can your local cage builder say that they have employed engineers to analyze their designs (most of which are blatant FIA copies). [/quote]
Looks like you are double talkin' there buddy.
The point is, the minimum requirements for a FIA cage are a joke. Obviously cars at the GT or Lemans level arent going to build their cages to the minimum level.
[quote] At least the cage you show is close to body unlike a lot of auto pwer cages that people employ.[/quote]
then you have obviously never seen a good autopower cage up close. Autopower cages are engineered extremely snug fit in a car [i]with the interior[/i] and allowing for manufacturing variances. I have seen autopower cages more snug than that cusco.
[quote] Got to trunkmonkey racing if you wan to see a perfect example of an american engineered cage that illustrates that people do not know what they are doing. Look at that cage if you want see how not to build a cage. [/QUOTE]
I have seen plenty of crappy cages thank you. I have also seen some good ones. What is your point here?
and when the hell did this turn into a American vs. European and FIA vs SCCA? :rolleyes:
[B]Bolt in cages are now illegal old cages that were of bolt in design are still legal. [/quote]
Not in road racing. Bolt in still legal.
[quote]CHromoly does not absorb energy as well as mild steel??? Sorry but it is not greater riggidity but rather weight savings the reason that people use chromoly. You are completely wrong here[/quote]
You are completely wrong. I will restate what I just said. CroMoly has a higher rigitidy than mild steel. I will pull out some metals books and reference the specific properties if you still dont believe me.
And as a trained and certified welder (although not my dayjob), ChroMo does not require "normalization" or whatever this garbage you speak of.
[quote]Look at last years cage rules there is not door bar requirement in SCCA prorally. People weld them in because they are not idiots, would trust a sanctioning body that does not require door bars for rally?[/quote]
Now you are just bashing SCCA? I made no claims about SCCAs superiority, and dont give a rats ass. FWIW, I definately wouldnt trust a sanctioning body that approves the above Cusco cage and lets you mount your harnesses 3 feet behind the seat.
[quote]FIA homologated cages are a joke? YEs [/quote]
[quote]Whiel there are many opinions the bottom line is that an FIA approved cage has had the design tested and examined by engineers employed by the FIA can your local cage builder say that they have employed engineers to analyze their designs (most of which are blatant FIA copies). [/quote]
Looks like you are double talkin' there buddy.
The point is, the minimum requirements for a FIA cage are a joke. Obviously cars at the GT or Lemans level arent going to build their cages to the minimum level.
[quote] At least the cage you show is close to body unlike a lot of auto pwer cages that people employ.[/quote]
then you have obviously never seen a good autopower cage up close. Autopower cages are engineered extremely snug fit in a car [i]with the interior[/i] and allowing for manufacturing variances. I have seen autopower cages more snug than that cusco.
[quote] Got to trunkmonkey racing if you wan to see a perfect example of an american engineered cage that illustrates that people do not know what they are doing. Look at that cage if you want see how not to build a cage. [/QUOTE]
I have seen plenty of crappy cages thank you. I have also seen some good ones. What is your point here?
and when the hell did this turn into a American vs. European and FIA vs SCCA? :rolleyes:
| dwx | 09-26-2003 03:24 PM |
There will always be differing opinions about cage construction and materials. I have read chassis articles from drag car/race car builders that say mild steel has no place in a modern racecar. That's due to the fact it's just not nearly as strong as chromoly steel. Chromoly is still steel, it's not aluminum, so I wouldn't compare those two together.
I'm surprised you are a welder and do not know what normalization is? When you reheat the chromoly for welding it then becomes brittle when it rehardens. Normalization is heating up the entire structure again to "normalize" the material throughout, which returns it to its original strength. If it's not done there is a good chance the tubing will crack at or around the weld because you made it much more brittle.
All WRC cages are built from T45. You can buy an Impreza cage from Prodrive, it's also T45. Many US rallyists wish SCCA rally would abandon their current cage specs and use FIA specs. Pre-built FIA cages are legal for US rally but you can't build a cage to FIA specs or out of T45. T45 isn't really available in the US however.
If that's an STi cage, I've never seen anything that said it was FIA certified... afaik it's just a cosmetic piece that they sell.
I'm surprised you are a welder and do not know what normalization is? When you reheat the chromoly for welding it then becomes brittle when it rehardens. Normalization is heating up the entire structure again to "normalize" the material throughout, which returns it to its original strength. If it's not done there is a good chance the tubing will crack at or around the weld because you made it much more brittle.
All WRC cages are built from T45. You can buy an Impreza cage from Prodrive, it's also T45. Many US rallyists wish SCCA rally would abandon their current cage specs and use FIA specs. Pre-built FIA cages are legal for US rally but you can't build a cage to FIA specs or out of T45. T45 isn't really available in the US however.
If that's an STi cage, I've never seen anything that said it was FIA certified... afaik it's just a cosmetic piece that they sell.
| nevr2qk | 09-26-2003 06:23 PM |
[QUOTE][i]Originally posted by johnfelstead [/i]
[B]Nope, sorry but that isnt true at all. You are trying to re-write the laws of physics with that one. On impact your body has a set momentum, that will not increase as your body travels as you are not putting any more energy into your body./B][/QUOTE]
I was trying to quickly show a relative difference between you and the car. You are correct, and I apologize for rushing a reply.
More accurately, the problem is the relative speed between you and the car. The car is decelerating during the time the belts are stretching. The longer this time, the more the car will have slowed while you remain in motion.
You're right that increasing the time the body is decelerated is good, but when the belts reach their limit, you're slowed to the car's current speed [i]immediately[/i]. The belt either holds at that point or fails catastrophically- there's no cushion to it (well, there would be a little as the belt failed, but then the belt really becomes the least of your worries).
The longer the belts stretch, the higher the peak load on the body. It's this instantaneous (impulse, if you prefer) force that does the most damage. This is also the same reason why you want your belts as tight as possible. The belts [i]are[/i] there to hold you in place. It's up to the vehicle to absorb the energy of the crash.
wrb- I'll reply later. I'm in a rush again.
Brock
[B]Nope, sorry but that isnt true at all. You are trying to re-write the laws of physics with that one. On impact your body has a set momentum, that will not increase as your body travels as you are not putting any more energy into your body./B][/QUOTE]
I was trying to quickly show a relative difference between you and the car. You are correct, and I apologize for rushing a reply.
More accurately, the problem is the relative speed between you and the car. The car is decelerating during the time the belts are stretching. The longer this time, the more the car will have slowed while you remain in motion.
You're right that increasing the time the body is decelerated is good, but when the belts reach their limit, you're slowed to the car's current speed [i]immediately[/i]. The belt either holds at that point or fails catastrophically- there's no cushion to it (well, there would be a little as the belt failed, but then the belt really becomes the least of your worries).
The longer the belts stretch, the higher the peak load on the body. It's this instantaneous (impulse, if you prefer) force that does the most damage. This is also the same reason why you want your belts as tight as possible. The belts [i]are[/i] there to hold you in place. It's up to the vehicle to absorb the energy of the crash.
wrb- I'll reply later. I'm in a rush again.
Brock
| Ver. 8 STi WRB | 09-27-2003 05:17 AM |
Brock I think you miss the point, too much stretch is bad just as too much stiff is also. When a belt stretches it is not just stretching at the same speed but rather decelerating your body until it no longers stretches at which point the body will encounter peak load. What you are trying to avoid is instantaneous peak load.
Next subject I think you are missing is that if the body decelerates too quickly there is a disparity between the speed of the head and that of the torso which can cause sever basal skull injuries. THis is why the Hans trys to keep the head and torso decelerating at the same rate.
Elgorey:
Normalization is a generally accepted term, though you are partially correct about one thing, there is a school of thought that says that since the tubing in a chromoly is very thin you do not necessarily need to normalize the welds. Why people claim that normalization is needed is because when you heat (or freeze) metal it rearranges the molecules which can change the strength of the meatl. Normalization brings theentire structure to a constant temp in order for the molecules to rearrange in a more stabel structure. Think of it as cryo treating rotors or gears, by lowering the temp you will rearrange the molecules to a more stable orientation.
FIA Vs. SCCA/Nasa vs. America Vs. Europe
Yes in a way this did become a classic us vs. them arguement because we do things very differently in the states and I do not understand it. In europe there is a very clear set of rules for different forms of racing. You are correct the bolt in cage is not suitable for road course or rally but fine for autocross. The FIA governs all forms of motorsportnot just WRC or BTCC or FIA GT racing. There are different regulations for each type of racing. You cannot just turn up at a race in europe with any FIA homologated cage and race. Cages are homologated per application there are Group N homologated cages and Group A homologated cages and dofferent ones for different forms of motorsport.There are only two companies world wide that produces a group N homologated cage for the GDA/GDB chassis and those are Custom Cages and Prodrive. Now there may be several different manufacturers that have homologated cages for the GDA/GDB for autocross or TSD rally.
FIA cages can only be produced by the company that homologated the design, though they can be installed by anyone a competitor chosses. The cages will be homologated and remain legal as long as no modifications were made to the design by the installer. You will provide the homologation form (this details the design for referrence) to the scrutineer so that he or she is able to see that the design has not been modified or changed or installed improperly.
SCCA Vs. FIA
SCCA would rather allow anyone with a tube bender and a mig welder to follow a vague design which changes every year design and install cages. Cage legality is not a clear thing withthe SCCA anyone that has tried to build a cage on their own can tell you that what is legal to one scrutineer may not be to another. The FIA does not allow you the choice of as many manufacturers or home builders but rather suppliers that employ a team of engineers that design a cage that meets safety standards (including crash testing) and said company must pay the costs associated with homologation. Each supplier is expending a great deal of money in order to homologate a cage and thus they are not always cheap. I feel that he rules laid out by the FIA are uch clearer and leave less to interpretation which is what I think is needed for uniform safety.
USA vs Europe
THe views of people in America vs. Europe when it comes to motorsport are light years apart. There are many factors that contribute to this a lot of which has to do with high liability racers and organizers face here in the United States. It is unfortunate because this colors our view of how things should be. Frankly if you go off course at a rally or flip into the stands at a road course you will probably be sued. At rally GB a year or two ago Carlos Sainz ran over 9 people, if that happened here the victims would have sued the organizers, Carlos, M-sport, Ford, etc.. That is why there is not as much motorsport in this country, the result is that we are years behind in technology for everything from performance to safety. there are hundreds of club rallies and circuit races all over europe every weekend, if the rules of the FIA are so lax then people would be getting killed in droves. Yes we have fewer fatalities in the US because frankly we have fewer competitors.
Sean from trunk monkey I have answered your pm my reply is in there.
Next subject I think you are missing is that if the body decelerates too quickly there is a disparity between the speed of the head and that of the torso which can cause sever basal skull injuries. THis is why the Hans trys to keep the head and torso decelerating at the same rate.
Elgorey:
Normalization is a generally accepted term, though you are partially correct about one thing, there is a school of thought that says that since the tubing in a chromoly is very thin you do not necessarily need to normalize the welds. Why people claim that normalization is needed is because when you heat (or freeze) metal it rearranges the molecules which can change the strength of the meatl. Normalization brings theentire structure to a constant temp in order for the molecules to rearrange in a more stabel structure. Think of it as cryo treating rotors or gears, by lowering the temp you will rearrange the molecules to a more stable orientation.
FIA Vs. SCCA/Nasa vs. America Vs. Europe
Yes in a way this did become a classic us vs. them arguement because we do things very differently in the states and I do not understand it. In europe there is a very clear set of rules for different forms of racing. You are correct the bolt in cage is not suitable for road course or rally but fine for autocross. The FIA governs all forms of motorsportnot just WRC or BTCC or FIA GT racing. There are different regulations for each type of racing. You cannot just turn up at a race in europe with any FIA homologated cage and race. Cages are homologated per application there are Group N homologated cages and Group A homologated cages and dofferent ones for different forms of motorsport.There are only two companies world wide that produces a group N homologated cage for the GDA/GDB chassis and those are Custom Cages and Prodrive. Now there may be several different manufacturers that have homologated cages for the GDA/GDB for autocross or TSD rally.
FIA cages can only be produced by the company that homologated the design, though they can be installed by anyone a competitor chosses. The cages will be homologated and remain legal as long as no modifications were made to the design by the installer. You will provide the homologation form (this details the design for referrence) to the scrutineer so that he or she is able to see that the design has not been modified or changed or installed improperly.
SCCA Vs. FIA
SCCA would rather allow anyone with a tube bender and a mig welder to follow a vague design which changes every year design and install cages. Cage legality is not a clear thing withthe SCCA anyone that has tried to build a cage on their own can tell you that what is legal to one scrutineer may not be to another. The FIA does not allow you the choice of as many manufacturers or home builders but rather suppliers that employ a team of engineers that design a cage that meets safety standards (including crash testing) and said company must pay the costs associated with homologation. Each supplier is expending a great deal of money in order to homologate a cage and thus they are not always cheap. I feel that he rules laid out by the FIA are uch clearer and leave less to interpretation which is what I think is needed for uniform safety.
USA vs Europe
THe views of people in America vs. Europe when it comes to motorsport are light years apart. There are many factors that contribute to this a lot of which has to do with high liability racers and organizers face here in the United States. It is unfortunate because this colors our view of how things should be. Frankly if you go off course at a rally or flip into the stands at a road course you will probably be sued. At rally GB a year or two ago Carlos Sainz ran over 9 people, if that happened here the victims would have sued the organizers, Carlos, M-sport, Ford, etc.. That is why there is not as much motorsport in this country, the result is that we are years behind in technology for everything from performance to safety. there are hundreds of club rallies and circuit races all over europe every weekend, if the rules of the FIA are so lax then people would be getting killed in droves. Yes we have fewer fatalities in the US because frankly we have fewer competitors.
Sean from trunk monkey I have answered your pm my reply is in there.
| Ver. 8 STi WRB | 09-27-2003 05:25 AM |
John did you notice that the LAtvala's crash was on the drivers side of the car? IT seems that the rearword rotation is what causes the injuries in most of these side impacts.
Another note about FIA cages the major resistance to FIA cages is the fact that since only a few manufacturers can supply them the price is higher. It all comes down to money people not safety as many would have you believe. 100 dollar helmet for a 100 dollar head.
Another note about FIA cages the major resistance to FIA cages is the fact that since only a few manufacturers can supply them the price is higher. It all comes down to money people not safety as many would have you believe. 100 dollar helmet for a 100 dollar head.
| nevr2qk | 09-29-2003 05:41 PM |
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[B]Brock I think you miss the point, too much stretch is bad just as too much stiff is also. When a belt stretches it is not just stretching at the same speed but rather decelerating your body until it no longers stretches at which point the body will encounter peak load. What you are trying to avoid is instantaneous peak load.[/B][/QUOTE]
Oh, so belt stretch is tune-able? What then, is the proper belt length to allow the right amount of stretch? Don't bother answering because next I'm going to point out that the answer requires you to know the severity of the collision.
You're making the assumption that the belt stretches at the end of the collision- at the point when the car has absorbed all the energy it- and that it provides a nice soft cushion at the end of the wreck. This is wrong. The belt starts stretching as soon as your weight transfers forward. While it's stretching, the car is decelerating at a rate faster than you. When the belt reaches it's limit, your body is forced to match the velocity of the car nearly instantaneously. If this peak load overlaps the vehicle's peak deceleration, you can be in serious trouble. You want the belt to stabilize before the vehicle, and the only best way to ensure this is to minimize belt stretch.
I don't think I can explain this any more clearly. If you still disagree, attach your shoulder harnesses all the way back on the trunklid. I'm here to help, but I guess it's your ass.
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i][b]
Next subject I think you are missing is that if the body decelerates too quickly there is a disparity between the speed of the head and that of the torso which can cause sever basal skull injuries. THis is why the Hans trys to keep the head and torso decelerating at the same rate. [/B][/QUOTE]
Wrong. Whiplash and other spinal injuries don't have anything to do with belt stretch. But I'm glad you brought it up- whiplash is the perfect analogy to belt stretch. Wish I'd thought of that myself.
I'll try to respond to your other posts later. Sorry for the delay, but I have other obligations.
In the meantime, you need to look up what you think you know about chromoly and the SCCA rules. From what I've glanced at, you're wrong about these topics as well. Listen to what elgorey has to say.
Brock
[B]Brock I think you miss the point, too much stretch is bad just as too much stiff is also. When a belt stretches it is not just stretching at the same speed but rather decelerating your body until it no longers stretches at which point the body will encounter peak load. What you are trying to avoid is instantaneous peak load.[/B][/QUOTE]
Oh, so belt stretch is tune-able? What then, is the proper belt length to allow the right amount of stretch? Don't bother answering because next I'm going to point out that the answer requires you to know the severity of the collision.
You're making the assumption that the belt stretches at the end of the collision- at the point when the car has absorbed all the energy it- and that it provides a nice soft cushion at the end of the wreck. This is wrong. The belt starts stretching as soon as your weight transfers forward. While it's stretching, the car is decelerating at a rate faster than you. When the belt reaches it's limit, your body is forced to match the velocity of the car nearly instantaneously. If this peak load overlaps the vehicle's peak deceleration, you can be in serious trouble. You want the belt to stabilize before the vehicle, and the only best way to ensure this is to minimize belt stretch.
I don't think I can explain this any more clearly. If you still disagree, attach your shoulder harnesses all the way back on the trunklid. I'm here to help, but I guess it's your ass.
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i][b]
Next subject I think you are missing is that if the body decelerates too quickly there is a disparity between the speed of the head and that of the torso which can cause sever basal skull injuries. THis is why the Hans trys to keep the head and torso decelerating at the same rate. [/B][/QUOTE]
Wrong. Whiplash and other spinal injuries don't have anything to do with belt stretch. But I'm glad you brought it up- whiplash is the perfect analogy to belt stretch. Wish I'd thought of that myself.
I'll try to respond to your other posts later. Sorry for the delay, but I have other obligations.
In the meantime, you need to look up what you think you know about chromoly and the SCCA rules. From what I've glanced at, you're wrong about these topics as well. Listen to what elgorey has to say.
Brock
| nevr2qk | 09-29-2003 08:49 PM |
[QUOTE][i]Originally posted by Ver. 8 STi WRB [/i]
[B]Did you know that technical regulations for FIA group A (super production) and Group N (production) touring cars are the same as though for Group A rally cars and Group N rally cars. Allow me to clarify a few myths that exist here in the states. Remember that on a race track though you have concrete barriers you also have run-off areas as well as gravel traps. Your car will decelerate before impact. Rally has many different types of impacts the worst being trees and rock walls. Even in a group 2 car with only one liter of displacement we have reached well over 100mph on stage which is similar speeds to circuit racing so saying that what is safe in rally and what is road course safe is not really a valid arguement. One person mentioned that you need the substrap to avoid sliding into the footwell, you are right that this is why we employ a sub strap but it is not as much of an issue in a saloon car as it is in a formula car. The difference is simple physics look at body position in a formula car vs in a saloon you are almos lying down (in modern F1 cars the drivers feet are about the same level as his head. Try it at home sti up in a chair and have a friend push from behind then ry is lying down which way do you subamrine more readily? In general in America (SCCA and NASA) people preach about cage rigidity theus (they have outlawed bolt in cages) but as John will attest many many big teams use bolt in cages. THe other thing that people preach in America is not to use Chromoly tubing and to use really thick mild steel (.120 or 095 wall) while in Europe most teams use FE45, T45 (4130), or CDS tubing 50mm main hoop and the walls are much thinnerthis is so they do not have to trully "normalize" the welds which is impossible unless you havea gigantic oven. When you use thin walled stuf normalization is not really an issue but here we have our own way of doing things. Another common SCCA/NASA arguement is that thin walled tubing is not as safe but what they fail to recognize when you increase outer diameter of a tube the wall can be thinner while actually being much stronger. You want the cage to deform because it absorbs energy yet here people see a cage deforming as a sign of poor design whish is not the case. Did you folks know that this year the SCCA did not require door bars for roll cages which I find absolutely irresponsible. Looking at the door bars on this guys cage they are too low they should extend from the bottom of the window sill to the floor in a diagonal. Whiel there are many opinions the bottom line is that an FIA approved cage has had the design tested and examined by engineers employed by the FIA can your local cage builder say that they have employed engineers to analyze their designs (most of which are blatant FIA copies). This is probably more than most of you ever wanted to know about cages and saftey equipment but I do not take safety lightly and I feel that there is a lot of misinformation on boards and the internet in general. I hope that most of you have understood the points I am trying to make which is safety is an engineered thing that must be thought out, you cannot just welld in a ton of bars or mount seatbelts any which way there is a logic to why people do things the way they do them and if used incorrectly they make a vehicle more dangerous then without them. if anyone ever has some cage or ally questions feel free to email me I am always willing to help people with cages, and harness questions. Nevr2qk you make a lot of good points in you post though assuming that road racing and rallying do not have similar levels of safety is a misconception (rally guys and roadrace guys generall yhave different schools of thought), the lecture by dr. trammel was about all safety and alot of it was geared to NASCAR guys (I beleive that they race saloons) but you are correct about the belt being pulled up though what they found was that the 5-point was not really anymore effective then properly utilized 4-points while 6-points were significantly more effective. Having bounced off more then roll cage in my life I will tell you that most of that padding is totally worthless in preventing injuries. YO uwill notice the only one on most cars being rallied in europe have only near the head becaause when used in concert with a helet is is sucssful but exposed limbs do not fair well with metal tubes no matter what is wrapped around them. Whatever makes you feel more comfortable though. [/B][/QUOTE]
WRB, it looks like I already addressed your later posts, though I didn't know I was at the time. Several comments appeared to have been directed to the Mother Of All Run-on Paragraphs, so I finally waded through it.
Here is what I was able to get out of it:
[b]road course vs. rally[/b]
I was suggesting a possibility why rally cars may be set up differently. A lowered chance of frontal impact is the only reason I could think of for the excess belt. I don't see anything inside the car that would prevent a main loop support / harness bar behind the seats. I admitted I don't know much about rally- if the danger is equivalent then all the more reason the shoulder belts should be shortened.
[b]upright vs. reclined[/b]
You concede submarining is not an issue in sedans, yet insist you saw a lecture, directed towards upright seats, advocating the importance of 6-points. Since the same breath claims 4 points are just as good as 5-points, I'm wary of either the speaker's knowledge or (more likely) your understanding of the lecture. True, the sub belt in a 5-point or 6-point system without leg straps doesn't carry much load, so in that context alone, a 4-point is "nearly as good". Unfortunately, the significant chance of abdomenal injury negates this comparison. Alternately / additionally, perhaps the speaker was advocating the use of 6-point systems with leg straps versus simple sub belts. I have a feeling you are inadvertantly over-generalizing something you heard.
[b]chromoly vs. mild steel[/b]
The alloy has a higher ultimate strength. Because of this, you can use a smaller diameter and/or thinner wall tubing to carry the same load. It allows a lighter weight, less obtrusive roll cage.
The drawback is that it's more brittle. After the initial impact, a mild steel cage will withstand subsequent better than chromoly. This the reason many racers prefer mild steel; it doesn't have a damn thing to do with the wall thickness, as you claim.
"Normalizing" is a worthless generic term. It doesn't mean dick. The term you're looking for is annealing, and if I remember my metallurgy correctly, it's not necessary for the thicknesses we're talking about.
[b]SCCA rules[/b]
Your comments about the SCCA not requiring side intrusion bars is also wrong. Side protection has been required at least since 1999 (that's the oldest GCR I have). I'll refer you to Section 18.2, Paragraph 7. This is for Showroom Stock, the most lax of cage requirements.
I expect your knowledge of other SCCA rules is equally poor. I sincerely doubt they would have outlawed bolt-in cages for SS, since it would hamper participants' ability to remove the cage and sell the vehicle.
[b]Padding[/b]
I supposed you've repeated the accidents you mention both with and without padding for a scientific comparison? Any layer of energy absorption helps. Just because it wasn't enough, doesn't mean it didn't work. I think you've hit your head one too many times.
We do agree on one thing, though. Planning a cage should be something thought out and analized. Many speed shops are just a bunch of grease monkeys like the rest of us. Just because they can work a welder, doesn't mean they have any clue what they're doing. If you want to do it right, have a custom cage engineered, and take the design to a professional welder.
Happy motoring.
Brock
[B]Did you know that technical regulations for FIA group A (super production) and Group N (production) touring cars are the same as though for Group A rally cars and Group N rally cars. Allow me to clarify a few myths that exist here in the states. Remember that on a race track though you have concrete barriers you also have run-off areas as well as gravel traps. Your car will decelerate before impact. Rally has many different types of impacts the worst being trees and rock walls. Even in a group 2 car with only one liter of displacement we have reached well over 100mph on stage which is similar speeds to circuit racing so saying that what is safe in rally and what is road course safe is not really a valid arguement. One person mentioned that you need the substrap to avoid sliding into the footwell, you are right that this is why we employ a sub strap but it is not as much of an issue in a saloon car as it is in a formula car. The difference is simple physics look at body position in a formula car vs in a saloon you are almos lying down (in modern F1 cars the drivers feet are about the same level as his head. Try it at home sti up in a chair and have a friend push from behind then ry is lying down which way do you subamrine more readily? In general in America (SCCA and NASA) people preach about cage rigidity theus (they have outlawed bolt in cages) but as John will attest many many big teams use bolt in cages. THe other thing that people preach in America is not to use Chromoly tubing and to use really thick mild steel (.120 or 095 wall) while in Europe most teams use FE45, T45 (4130), or CDS tubing 50mm main hoop and the walls are much thinnerthis is so they do not have to trully "normalize" the welds which is impossible unless you havea gigantic oven. When you use thin walled stuf normalization is not really an issue but here we have our own way of doing things. Another common SCCA/NASA arguement is that thin walled tubing is not as safe but what they fail to recognize when you increase outer diameter of a tube the wall can be thinner while actually being much stronger. You want the cage to deform because it absorbs energy yet here people see a cage deforming as a sign of poor design whish is not the case. Did you folks know that this year the SCCA did not require door bars for roll cages which I find absolutely irresponsible. Looking at the door bars on this guys cage they are too low they should extend from the bottom of the window sill to the floor in a diagonal. Whiel there are many opinions the bottom line is that an FIA approved cage has had the design tested and examined by engineers employed by the FIA can your local cage builder say that they have employed engineers to analyze their designs (most of which are blatant FIA copies). This is probably more than most of you ever wanted to know about cages and saftey equipment but I do not take safety lightly and I feel that there is a lot of misinformation on boards and the internet in general. I hope that most of you have understood the points I am trying to make which is safety is an engineered thing that must be thought out, you cannot just welld in a ton of bars or mount seatbelts any which way there is a logic to why people do things the way they do them and if used incorrectly they make a vehicle more dangerous then without them. if anyone ever has some cage or ally questions feel free to email me I am always willing to help people with cages, and harness questions. Nevr2qk you make a lot of good points in you post though assuming that road racing and rallying do not have similar levels of safety is a misconception (rally guys and roadrace guys generall yhave different schools of thought), the lecture by dr. trammel was about all safety and alot of it was geared to NASCAR guys (I beleive that they race saloons) but you are correct about the belt being pulled up though what they found was that the 5-point was not really anymore effective then properly utilized 4-points while 6-points were significantly more effective. Having bounced off more then roll cage in my life I will tell you that most of that padding is totally worthless in preventing injuries. YO uwill notice the only one on most cars being rallied in europe have only near the head becaause when used in concert with a helet is is sucssful but exposed limbs do not fair well with metal tubes no matter what is wrapped around them. Whatever makes you feel more comfortable though. [/B][/QUOTE]
WRB, it looks like I already addressed your later posts, though I didn't know I was at the time. Several comments appeared to have been directed to the Mother Of All Run-on Paragraphs, so I finally waded through it.
Here is what I was able to get out of it:
[b]road course vs. rally[/b]
I was suggesting a possibility why rally cars may be set up differently. A lowered chance of frontal impact is the only reason I could think of for the excess belt. I don't see anything inside the car that would prevent a main loop support / harness bar behind the seats. I admitted I don't know much about rally- if the danger is equivalent then all the more reason the shoulder belts should be shortened.
[b]upright vs. reclined[/b]
You concede submarining is not an issue in sedans, yet insist you saw a lecture, directed towards upright seats, advocating the importance of 6-points. Since the same breath claims 4 points are just as good as 5-points, I'm wary of either the speaker's knowledge or (more likely) your understanding of the lecture. True, the sub belt in a 5-point or 6-point system without leg straps doesn't carry much load, so in that context alone, a 4-point is "nearly as good". Unfortunately, the significant chance of abdomenal injury negates this comparison. Alternately / additionally, perhaps the speaker was advocating the use of 6-point systems with leg straps versus simple sub belts. I have a feeling you are inadvertantly over-generalizing something you heard.
[b]chromoly vs. mild steel[/b]
The alloy has a higher ultimate strength. Because of this, you can use a smaller diameter and/or thinner wall tubing to carry the same load. It allows a lighter weight, less obtrusive roll cage.
The drawback is that it's more brittle. After the initial impact, a mild steel cage will withstand subsequent better than chromoly. This the reason many racers prefer mild steel; it doesn't have a damn thing to do with the wall thickness, as you claim.
"Normalizing" is a worthless generic term. It doesn't mean dick. The term you're looking for is annealing, and if I remember my metallurgy correctly, it's not necessary for the thicknesses we're talking about.
[b]SCCA rules[/b]
Your comments about the SCCA not requiring side intrusion bars is also wrong. Side protection has been required at least since 1999 (that's the oldest GCR I have). I'll refer you to Section 18.2, Paragraph 7. This is for Showroom Stock, the most lax of cage requirements.
I expect your knowledge of other SCCA rules is equally poor. I sincerely doubt they would have outlawed bolt-in cages for SS, since it would hamper participants' ability to remove the cage and sell the vehicle.
[b]Padding[/b]
I supposed you've repeated the accidents you mention both with and without padding for a scientific comparison? Any layer of energy absorption helps. Just because it wasn't enough, doesn't mean it didn't work. I think you've hit your head one too many times.
We do agree on one thing, though. Planning a cage should be something thought out and analized. Many speed shops are just a bunch of grease monkeys like the rest of us. Just because they can work a welder, doesn't mean they have any clue what they're doing. If you want to do it right, have a custom cage engineered, and take the design to a professional welder.
Happy motoring.
Brock
| IXLR8 | 09-29-2003 10:38 PM |
[QUOTE][i]Originally posted by johnfelstead [/i]
[B]You, sir, are incredibly rude... [/B][/QUOTE]
Just had an opportunity to read through this thread, and while I'm only an occasional reader/poster here, what I find particularly rude and offensive is the superior, lecturing tone exhibited in Ver. 8 STi WRB posts.
If the intent is to indeed clearify the "misinformation on boards and the internet in general" then Ver. 8 STi WRB might want to consider a less condesending approach in presenting his opinions...
If that proves difficult, one might want to reflect on some of the less wonderful contributions the British have made to engineering and automotives, like the Whitworth Standard, and Lucas electrics, to name only two, before spewing forth on the superiority of FIA regulations.
[B]You, sir, are incredibly rude... [/B][/QUOTE]
Just had an opportunity to read through this thread, and while I'm only an occasional reader/poster here, what I find particularly rude and offensive is the superior, lecturing tone exhibited in Ver. 8 STi WRB posts.
If the intent is to indeed clearify the "misinformation on boards and the internet in general" then Ver. 8 STi WRB might want to consider a less condesending approach in presenting his opinions...
If that proves difficult, one might want to reflect on some of the less wonderful contributions the British have made to engineering and automotives, like the Whitworth Standard, and Lucas electrics, to name only two, before spewing forth on the superiority of FIA regulations.
| dwx | 09-30-2003 01:24 PM |
Normalization is not annealing, nor is it tempering. They are all similar in process but differ in the temperatures you operate at. Normalization is its own term and process.
The FIA is based in France, not England. :)
Here is an interesting materials document from the FIA:
[url]http://www.fia.com/regle/annexe_K/mater-Thorough-A.pdf[/url]
The FIA is based in France, not England. :)
Here is an interesting materials document from the FIA:
[url]http://www.fia.com/regle/annexe_K/mater-Thorough-A.pdf[/url]
| nevr2qk | 09-30-2003 01:48 PM |
[QUOTE][i]Originally posted by dwx [/i]
[B]Normalization is not annealing, nor is it tempering. They are all similar in process but differ in the temperatures you operate at. Normalization is its own term and process.[/B][/QUOTE]
Hmmm. I'll have to check tonight to see if I kept my metallurgy book. It's been a few years, but I sure don't remember "normalizing" being an actual process. Thanks, though- I guess I stand corrected.
Was I wrong about it not being required for thin-walled tubing, too?
Brock
[B]Normalization is not annealing, nor is it tempering. They are all similar in process but differ in the temperatures you operate at. Normalization is its own term and process.[/B][/QUOTE]
Hmmm. I'll have to check tonight to see if I kept my metallurgy book. It's been a few years, but I sure don't remember "normalizing" being an actual process. Thanks, though- I guess I stand corrected.
Was I wrong about it not being required for thin-walled tubing, too?
Brock
| IXLR8 | 09-30-2003 01:48 PM |
[QUOTE][i]Originally posted by dwx [/i]
[B]The FIA is based in France, not England. [/B][/QUOTE]
Didn't suggest otherwise... but that would explain why it's a French acronym... besides, France, England, what's the difference? They're all "Old Europe", or so Don Rumsfeld says.
[B]The FIA is based in France, not England. [/B][/QUOTE]
Didn't suggest otherwise... but that would explain why it's a French acronym... besides, France, England, what's the difference? They're all "Old Europe", or so Don Rumsfeld says.
| dwx | 09-30-2003 04:56 PM |
[QUOTE][i]Originally posted by nevr2qk [/i]
[B]
Hmmm. I'll have to check tonight to see if I kept my metallurgy book. It's been a few years, but I sure don't remember "normalizing" being an actual process. Thanks, though- I guess I stand corrected.
Was I wrong about it not being required for thin-walled tubing, too?
Brock [/B][/QUOTE]
From what I've heard, and I'm no metals expert, it's not as important when welding thin tubing. Although if you look at that FIA materials document they do recommend it for T45/4130 Chromoly I believe.
[B]
Hmmm. I'll have to check tonight to see if I kept my metallurgy book. It's been a few years, but I sure don't remember "normalizing" being an actual process. Thanks, though- I guess I stand corrected.
Was I wrong about it not being required for thin-walled tubing, too?
Brock [/B][/QUOTE]
From what I've heard, and I'm no metals expert, it's not as important when welding thin tubing. Although if you look at that FIA materials document they do recommend it for T45/4130 Chromoly I believe.
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