| crystalhelix | 09-19-2005 02:04 PM |
More camber...less stopping power?
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Ok, so I understand why running more camber would reduce my braking ability. It seems the car stopped much_better in AS trim with -1 camber vs ESP camber set at near -3. Has anybody gone through this and gotten the same feeling that you have lost something you loved. I guess you are turning more than you are braking so it's better to have the camber.
Thoughts?
Thoughts?
| Jsortor | 09-19-2005 02:32 PM |
Its a trade-off. With my Camber, I also barely get 1.9 60 foots in the pro's too, let alone the braking deal. Good thing I trail brake sideways into every turn.....
| jmott | 09-19-2005 02:42 PM |
[QUOTE=crystalhelix]Ok, so I understand why running more camber would reduce my braking ability. It seems the car stopped much_better in AS trim with -1 camber vs ESP camber set at near -3. Has anybody gone through this and gotten the same feeling that you have lost something you loved. I guess you are turning more than you are braking so it's better to have the camber.
Thoughts?[/QUOTE]
Yep, that is the trade off. Also a tradeoff in accelerating, though subarus tend not to notice that tradeoff as much for obvious reason.
This is always why race cars tend to have double wishbone suspensions. They don't need as much static negative camber for optimum cornering.
Thoughts?[/QUOTE]
Yep, that is the trade off. Also a tradeoff in accelerating, though subarus tend not to notice that tradeoff as much for obvious reason.
This is always why race cars tend to have double wishbone suspensions. They don't need as much static negative camber for optimum cornering.
| AUTOwrXER | 09-19-2005 03:15 PM |
My thought is that you should stiffen the suspension so that you don't need -3+ degrees of camber. My brakes still work very well at -2.6
You shouldn't be running nearly as much camber in the rear, so acceleration should not be an issue.
You shouldn't be running nearly as much camber in the rear, so acceleration should not be an issue.
| sciolist | 09-19-2005 04:09 PM |
There's also the caster variable to consider.
| jmott | 09-19-2005 04:46 PM |
even with a stiff suspension mcpherson strut cars are going to be fastest with -3.5 to -4.0 degrees of camber up front.
increasing static caster does get you some dyamic negative camber, but it is a very small amount. It also creates a pretty profound side effect of increased weigh transfer (lots of it) as you turn the wheel. More caster = more unloading of the inside rear wheel as you turn the steering wheel.
increasing static caster does get you some dyamic negative camber, but it is a very small amount. It also creates a pretty profound side effect of increased weigh transfer (lots of it) as you turn the wheel. More caster = more unloading of the inside rear wheel as you turn the steering wheel.
| Homemade WRX | 09-20-2005 12:41 AM |
yeah, castor and camber gain would be my choice for getting the wanted angle...but even with camber gain through suspenion travel you still loose tire contact do to the camber increase...so there is always a trade off ;)
| AUTOwrXER | 09-20-2005 10:58 AM |
[QUOTE=jmott]even with a stiff suspension mcpherson strut cars are going to be fastest with -3.5 to -4.0 degrees of camber up front.
[/QUOTE]
Maybe with bias-ply tires, but I've been getting even tire temps on the skidpad with -2.6 to-3.2 depending on the tire. -3.5 or more is a ton.
[/QUOTE]
Maybe with bias-ply tires, but I've been getting even tire temps on the skidpad with -2.6 to-3.2 depending on the tire. -3.5 or more is a ton.
| AtomicRacer | 09-20-2005 11:47 AM |
With -3.5 camber I am still about 20-25 degrees hotter on the outside. That is with Cobb bars and pink springs though. I am going to upgrade to coilovers soon and almost double the spring rate. I will then test again, hopefully I can take some camber out and improve braking. I am also considering a stiffer front bar but I want to see where the spring change alone gets me.
-Paul
ps: Nice meeting you at Nationals Joel, sorry I didn't get to stop by your car after Karen introduced us. Kinda ran out of time. =/
-Paul
ps: Nice meeting you at Nationals Joel, sorry I didn't get to stop by your car after Karen introduced us. Kinda ran out of time. =/
| AUTOwrXER | 09-20-2005 01:09 PM |
Good meeting you too Paul. What spring rates are you running now?
| AtomicRacer | 09-20-2005 02:33 PM |
Current spring rates are (for STi "pink" springs) 257 front and 217 rear on stock struts. The Cobb bars are 25mm hollow. I have the new Whiteline 27-29mm solid front bar and 24-26mm solid rear bar but haven't tried them yet.
| AUTOwrXER | 09-20-2005 03:43 PM |
I could see you getting a lot of roll with that setup. Adding camber is the band-aid approach. With a stiffer roll rate I don't think you'll need as much camber, which will also help braking and accelerating.
If you think about it, with a solid suspension you would essentially want 0 camber. Technically it would still be a very slight negative inclination, but very little. Given that our suspensions need to absorb bumps, that is not an option, but the firmer the rate the less camber you should need.
If you think about it, with a solid suspension you would essentially want 0 camber. Technically it would still be a very slight negative inclination, but very little. Given that our suspensions need to absorb bumps, that is not an option, but the firmer the rate the less camber you should need.
| Draken | 09-20-2005 03:54 PM |
I'm fairly even with tire temps at -3 up front. 10k/8k setup, 28mm front bar. But i'm also running fairly narrow wheels for my 275 tires...so i think wider wheels would let me run less camber to avoid rollover.
Chris H.
Chris H.
| wrx2.0 555 | 09-20-2005 04:36 PM |
With 10k/9k spring rates on my WRX and dampening set almost to full stiff on my Tein HA's--with front and rear bars also--I had -3 degrees up front with very even tire temps.
I had a co-driver at the Atlanta SeDiv's and we measured each time both of us came in and they were pretty consistantly even.
As far as the topic is concerned, i never noticed any ill effects on braking...
Scott
I had a co-driver at the Atlanta SeDiv's and we measured each time both of us came in and they were pretty consistantly even.
As far as the topic is concerned, i never noticed any ill effects on braking...
Scott
| sciolist | 09-20-2005 06:19 PM |
[QUOTE=AUTOwrXER]If you think about it, with a solid suspension you would essentially want 0 camber. Technically it would still be a very slight negative inclination, but very little. Given that our suspensions need to absorb bumps, that is not an option, but the firmer the rate the less camber you should need.[/QUOTE]
Yet many of us seem to have both stiff suspensions *and* a healthy portion of front camber. I've got 11K springs and the Strano bar in front, and my tire wear and temperatures are pretty uniform with -3.0. I think you have a fairly comperable level of rigidity, and you're talking about a working range of -2.6 to -3.2.
It feels like my tires could be providing better grip launching and in short stop boxes ... even perhaps in hard entry braking, but intuition suggests that optimizing cornering is the higher priority.
Adding a little caster and backing off on the camber seems like the only other option. I haven't tried less than -3.0 static camber in front with race tires, though.
Yet many of us seem to have both stiff suspensions *and* a healthy portion of front camber. I've got 11K springs and the Strano bar in front, and my tire wear and temperatures are pretty uniform with -3.0. I think you have a fairly comperable level of rigidity, and you're talking about a working range of -2.6 to -3.2.
It feels like my tires could be providing better grip launching and in short stop boxes ... even perhaps in hard entry braking, but intuition suggests that optimizing cornering is the higher priority.
Adding a little caster and backing off on the camber seems like the only other option. I haven't tried less than -3.0 static camber in front with race tires, though.
| jmott | 09-20-2005 06:24 PM |
[QUOTE=AUTOwrXER]Maybe with bias-ply tires, but I've been getting even tire temps on the skidpad with -2.6 to-3.2 depending on the tire. -3.5 or more is a ton.[/QUOTE]
Driver harder then. solo2 national champs are running -3.5 to -4
It might be that the tires or surface you were testing on don't afford as much grip though, which would lead to less need for camber.
Driver harder then. solo2 national champs are running -3.5 to -4
It might be that the tires or surface you were testing on don't afford as much grip though, which would lead to less need for camber.
| AUTOwrXER | 09-20-2005 07:46 PM |
[QUOTE=jmott]Driver harder then. solo2 national champs are running -3.5 to -4
It might be that the tires or surface you were testing on don't afford as much grip though, which would lead to less need for camber.[/QUOTE]
You're right. I don't know how to drive a skidpad at the limit.
FWIW, Lieber, Khanghi, and Daddio were all at about -2.5 in their Evos.
Name a national champion in a strut car with -3.5 to -4.0
It might be that the tires or surface you were testing on don't afford as much grip though, which would lead to less need for camber.[/QUOTE]
You're right. I don't know how to drive a skidpad at the limit.
FWIW, Lieber, Khanghi, and Daddio were all at about -2.5 in their Evos.
Name a national champion in a strut car with -3.5 to -4.0
| Jsortor | 09-20-2005 10:24 PM |
[QUOTE=AUTOwrXER]You're right. I don't know how to drive a skidpad at the limit.
FWIW, Lieber, Khanghi, and Daddio were all at about -2.5 in their Evos.
Name a national champion in a strut car with -3.5 to -4.0[/QUOTE]
I raise my hand. And although it isn't a Subaru, I believe Vic Sias also runs about 4 deg in the front of his BMW.
FWIW, Lieber, Khanghi, and Daddio were all at about -2.5 in their Evos.
Name a national champion in a strut car with -3.5 to -4.0[/QUOTE]
I raise my hand. And although it isn't a Subaru, I believe Vic Sias also runs about 4 deg in the front of his BMW.
| jmott | 09-20-2005 11:13 PM |
[QUOTE=AUTOwrXER]You're right. I don't know how to drive a skidpad at the limit.
FWIW, Lieber, Khanghi, and Daddio were all at about -2.5 in their Evos.
Name a national champion in a strut car with -3.5 to -4.0[/QUOTE]
the DSP and SM and STX champs this year.
perhaps the subies just have some better geometry or track width, or perhaps they could learn a lesson from the bmw guys? heh.
Daddio didn't do so well so maybe he could have used more...and really I would be surprised if he only was running -2.5 up front.
FWIW, Lieber, Khanghi, and Daddio were all at about -2.5 in their Evos.
Name a national champion in a strut car with -3.5 to -4.0[/QUOTE]
the DSP and SM and STX champs this year.
perhaps the subies just have some better geometry or track width, or perhaps they could learn a lesson from the bmw guys? heh.
Daddio didn't do so well so maybe he could have used more...and really I would be surprised if he only was running -2.5 up front.
| crystalhelix | 09-21-2005 11:25 AM |
I think I would have serious problems at full lock with that much camber rubbing the hell out of the fender liners unless you offset the wheels even more. I have good even wear on front tires with -3, on 255 victos. Next year I may have to evaluate with a bigger tire. Running 600/500 and the addco bar, no rear bar. I guess I could consider more caster as well.
PS - My camber plates are pretty much maxed so I have no idea how to even go much more with camber.
Justin
PS - My camber plates are pretty much maxed so I have no idea how to even go much more with camber.
Justin
| SloRice | 09-21-2005 11:51 AM |
Justin...are you running the 600/500, addco bar, no bar setup right now??
If so, need a 2nd driver on Sunday at Beaver?? :)
If so, need a 2nd driver on Sunday at Beaver?? :)
| WRX_Mundi | 09-21-2005 12:20 PM |
I ran last year with -2.8 camber in the front (STi pink springs, iPD sway bars, so relatively soft suspension). I used an insertion pyrometer quite a few times including at test and tunes where I could get 5 back-to-back runs on a course. I got pretty even temperatures with that. However, the outside of the tire still gets most of the wear -- my tires look nothing like the Vettes which seem to have perfectly uniform wear across the entire tire. But that could be my driving and/or the 59% front weight.
I tried 4 degrees negative camber for the last few events. The pyrometer now shows hotter on the inside. With decent tires the car does very well though.
I had some Hoosiers that were just showing a touch of cord on the outside shoulder, so had them flipped. When I had them on the back (-1.3 camber) the inside shoulder wasn't touched at all. I made the mistake of putting them on the front. Everyone else was complaining that the surface didn't offer much grip. I had plenty of grip -- until I had to brake (60-15mph in a straight line). Ack! I had to start braking 20+ feet before anyone else as the car just wouldn't slow down! After four runs the "just see a touch of white" cording on the front inside had turned into metal sticking out of the tire. So certanily 4 degrees makes the front tires under straight line braking use the insides heavily.
I just had my PDE camber plates turned from camber only back to caster/camber, which swapped 0.7 degrees of camber for caster. So now I'm at -3.3 camber and +5.6 caster. We'll see how that works out this weekend. I suspect the -3.3 will be a little nicer, and more caster can't hurt at all. Next year I think I'll get the big Strano front bar to help control the roll some more.
I tried 4 degrees negative camber for the last few events. The pyrometer now shows hotter on the inside. With decent tires the car does very well though.
I had some Hoosiers that were just showing a touch of cord on the outside shoulder, so had them flipped. When I had them on the back (-1.3 camber) the inside shoulder wasn't touched at all. I made the mistake of putting them on the front. Everyone else was complaining that the surface didn't offer much grip. I had plenty of grip -- until I had to brake (60-15mph in a straight line). Ack! I had to start braking 20+ feet before anyone else as the car just wouldn't slow down! After four runs the "just see a touch of white" cording on the front inside had turned into metal sticking out of the tire. So certanily 4 degrees makes the front tires under straight line braking use the insides heavily.
I just had my PDE camber plates turned from camber only back to caster/camber, which swapped 0.7 degrees of camber for caster. So now I'm at -3.3 camber and +5.6 caster. We'll see how that works out this weekend. I suspect the -3.3 will be a little nicer, and more caster can't hurt at all. Next year I think I'll get the big Strano front bar to help control the roll some more.
| jmott | 09-21-2005 02:21 PM |
Vettes run around -2.5 front camber, but with double wishbones their camber curves are nicer. and they are lower, and wider, so they get less roll anyway.
us poor e36 BMWs are so narrow we are about to flip over half the time, lol
[QUOTE=WRX_Mundi]I ran last year with -2.8 camber in the front (STi pink springs, iPD sway bars, so relatively soft suspension). I used an insertion pyrometer quite a few times including at test and tunes where I could get 5 back-to-back runs on a course. I got pretty even temperatures with that. However, the outside of the tire still gets most of the wear -- my tires look nothing like the Vettes which seem to have perfectly uniform wear across the entire tire. But that could be my driving and/or the 59% front weight.
I tried 4 degrees negative camber for the last few events. The pyrometer now shows hotter on the inside. With decent tires the car does very well though.
I had some Hoosiers that were just showing a touch of cord on the outside shoulder, so had them flipped. When I had them on the back (-1.3 camber) the inside shoulder wasn't touched at all. I made the mistake of putting them on the front. Everyone else was complaining that the surface didn't offer much grip. I had plenty of grip -- until I had to brake (60-15mph in a straight line). Ack! I had to start braking 20+ feet before anyone else as the car just wouldn't slow down! After four runs the "just see a touch of white" cording on the front inside had turned into metal sticking out of the tire. So certanily 4 degrees makes the front tires under straight line braking use the insides heavily.
I just had my PDE camber plates turned from camber only back to caster/camber, which swapped 0.7 degrees of camber for caster. So now I'm at -3.3 camber and +5.6 caster. We'll see how that works out this weekend. I suspect the -3.3 will be a little nicer, and more caster can't hurt at all. Next year I think I'll get the big Strano front bar to help control the roll some more.[/QUOTE]
us poor e36 BMWs are so narrow we are about to flip over half the time, lol
[QUOTE=WRX_Mundi]I ran last year with -2.8 camber in the front (STi pink springs, iPD sway bars, so relatively soft suspension). I used an insertion pyrometer quite a few times including at test and tunes where I could get 5 back-to-back runs on a course. I got pretty even temperatures with that. However, the outside of the tire still gets most of the wear -- my tires look nothing like the Vettes which seem to have perfectly uniform wear across the entire tire. But that could be my driving and/or the 59% front weight.
I tried 4 degrees negative camber for the last few events. The pyrometer now shows hotter on the inside. With decent tires the car does very well though.
I had some Hoosiers that were just showing a touch of cord on the outside shoulder, so had them flipped. When I had them on the back (-1.3 camber) the inside shoulder wasn't touched at all. I made the mistake of putting them on the front. Everyone else was complaining that the surface didn't offer much grip. I had plenty of grip -- until I had to brake (60-15mph in a straight line). Ack! I had to start braking 20+ feet before anyone else as the car just wouldn't slow down! After four runs the "just see a touch of white" cording on the front inside had turned into metal sticking out of the tire. So certanily 4 degrees makes the front tires under straight line braking use the insides heavily.
I just had my PDE camber plates turned from camber only back to caster/camber, which swapped 0.7 degrees of camber for caster. So now I'm at -3.3 camber and +5.6 caster. We'll see how that works out this weekend. I suspect the -3.3 will be a little nicer, and more caster can't hurt at all. Next year I think I'll get the big Strano front bar to help control the roll some more.[/QUOTE]
| AUTOwrXER | 09-21-2005 05:01 PM |
[QUOTE=jmott]Daddio didn't do so well so maybe he could have used more...and really I would be surprised if he only was running -2.5 up front.[/QUOTE]
Mark had a terrible first day, but set fastest time in SM on the North course (saying he felt like he left at least a second from mistakes, plus driving on a torn right calf muscle). Here's a link where he describes his setup: [url]http://forums.evolutionm.net/showthread.php?t=135354&page=16&pp=15[/url] About half way down he says he's running -2.4
Navid and Tak both said they were at -2.5 during our GRM shoot Wednesday morning. Perhaps the Bimmers are undersprung or have an even worse camber curve than the rally cars. I have yet to see a rally car need that much camber on V710s or SO4/5s.
Mark had a terrible first day, but set fastest time in SM on the North course (saying he felt like he left at least a second from mistakes, plus driving on a torn right calf muscle). Here's a link where he describes his setup: [url]http://forums.evolutionm.net/showthread.php?t=135354&page=16&pp=15[/url] About half way down he says he's running -2.4
Navid and Tak both said they were at -2.5 during our GRM shoot Wednesday morning. Perhaps the Bimmers are undersprung or have an even worse camber curve than the rally cars. I have yet to see a rally car need that much camber on V710s or SO4/5s.
| crystalhelix | 09-21-2005 09:36 PM |
[QUOTE=SloRice]Justin...are you running the 600/500, addco bar, no bar setup right now??
If so, need a 2nd driver on Sunday at Beaver?? :)[/QUOTE]
I will PM you about this tommorow. I am working on my UTEC now and need to get everything wraped up so I can send my TXS Tuner back to TXS for a Tuner Pro upgrade and repair. If it was any other weeked I'd say yes but I'll explain.
I have worn through two sets of R-comps at -3 and they both wore perfect. Does that say anything to what proper camber is?
Jr
If so, need a 2nd driver on Sunday at Beaver?? :)[/QUOTE]
I will PM you about this tommorow. I am working on my UTEC now and need to get everything wraped up so I can send my TXS Tuner back to TXS for a Tuner Pro upgrade and repair. If it was any other weeked I'd say yes but I'll explain.
I have worn through two sets of R-comps at -3 and they both wore perfect. Does that say anything to what proper camber is?
Jr
| ericdc | 09-22-2005 12:15 PM |
[QUOTE=crystalhelix]If it was any other weeked I'd say yes but I'll explain.[/QUOTE]
Somebody wants to win the DOY title :) . Justin DO NOT let Nick psyche you out.... Just go out there and drive like you always do... fast and smooth. If you try too hard you will guarantee him the title.
Good luck.
Somebody wants to win the DOY title :) . Justin DO NOT let Nick psyche you out.... Just go out there and drive like you always do... fast and smooth. If you try too hard you will guarantee him the title.
Good luck.
| crystalhelix | 09-22-2005 12:18 PM |
[QUOTE=ericdc]Somebody wants to win the DOY title :) . Justin DO NOT let Nick psyche you out.... Just go out there and drive like you always do... fast and smooth. If you try too hard you will guarantee him the title.
Good luck.[/QUOTE]
Now I guess I don't have to. Thanks for the words Eric!;) Good luck with Street Tire class!
SloRice - Pming you.
Good luck.[/QUOTE]
Now I guess I don't have to. Thanks for the words Eric!;) Good luck with Street Tire class!
SloRice - Pming you.
| WRX_Mundi | 09-22-2005 07:54 PM |
[QUOTE=crystalhelix]I have worn through two sets of R-comps at -3 and they both wore perfect. Does that say anything to what proper camber is?[/quote]I think it's becoming fairly clear even with different suspension setups. I found -2.8 to be pretty even temps and -4 to be too much (I had to at least try it once). You find -3 to be even. Sciolist finds -3 to be pretty even. wrx2.0 finds -3 to be even temps. Draken finds -3 to be fairly even. AtomicRacer found -3.5 to be too much. Autowrxer says -2.6 to -3.2 gives even temps.
I think Autowrxer has tried a lot of different setups and his car is fairly well set up. Looks like we've reached at least some consensus on what camber settings give even temperatures across a relatively wide range of setups. Surprisingly narrow given we have front spring rates varying from 257 to 616 with different bars as well.
I think Autowrxer has tried a lot of different setups and his car is fairly well set up. Looks like we've reached at least some consensus on what camber settings give even temperatures across a relatively wide range of setups. Surprisingly narrow given we have front spring rates varying from 257 to 616 with different bars as well.
| AtomicRacer | 09-23-2005 10:17 AM |
[QUOTE=WRX_Mundi]I think it's becoming fairly clear even with different suspension setups. I found -2.8 to be pretty even temps and -4 to be too much (I had to at least try it once). You find -3 to be even. Sciolist finds -3 to be pretty even. wrx2.0 finds -3 to be even temps. Draken finds -3 to be fairly even. [b]AtomicRacer found -3.5 to be too much[/b]. Autowrxer says -2.6 to -3.2 gives even temps.
I think Autowrxer has tried a lot of different setups and his car is fairly well set up. Looks like we've reached at least some consensus on what camber settings give even temperatures across a relatively wide range of setups. Surprisingly narrow given we have front spring rates varying from 257 to 616 with different bars as well.[/QUOTE]
With -3.5 and soft springs / med front bar I was rolling too much and still getting hot on the outside. It was also affecting my braking, so in that way it was too much. I am sure with a stiffer setup I will be at -3.0 or less.
-Paul
I think Autowrxer has tried a lot of different setups and his car is fairly well set up. Looks like we've reached at least some consensus on what camber settings give even temperatures across a relatively wide range of setups. Surprisingly narrow given we have front spring rates varying from 257 to 616 with different bars as well.[/QUOTE]
With -3.5 and soft springs / med front bar I was rolling too much and still getting hot on the outside. It was also affecting my braking, so in that way it was too much. I am sure with a stiffer setup I will be at -3.0 or less.
-Paul
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