Thứ Sáu, 13 tháng 1, 2017

Need info on seam welding and building a cage. part 1

thebusiness999 03-18-2003 03:43 AM

Need info on seam welding and building a cage.
A couple buddies of mine have decided that they want to seam weld and cage up my car. They have a welder and said they'd do the labor for free...I just have to pay for materials (and help of course).

The opportunity sounds very tempting, but we all want to learn everything we can about seam welding and caging up a car before stripping my car and starting this project.

Do you all know of any books, websites, or people I can contact to learn more about this process? Since I only have to pay for materials I'd like to go for chromoly (unless you recommend some other material)...what thickness would you recommend?

My car's my baby and I don't want to mess with such a serious issue without knowing what we're all doing. Any sources of information you could provide would be much appreciated.

Thanks,
Paul
Geek Guy 03-18-2003 07:47 AM

Just whipping together a cage is not something to take lightly. There's a reason cage builders charge $4000 for their work. That being said, there are many things that you have to worry about.

1. Is the welder powerful enough to handle the thickness of pipe requred?

2. Do you have a pipe bender big enough for the pipe?

3. Does he have a car rotarty thingy?

4. The guy building the cage, is this just an aside thing, or afull time job? It it's an aside, be prepared to be without your car for about half of the year.

5. Remove the WHOLE interior.

6. Evacuate all of the gas from the tank, fuel lings.

7. Has he ever built a cage before?

8. Why do you need a cage?

And many, many more questions, but I just woke up, so this is a good start.
Kha0S 03-18-2003 08:53 AM

I'm going to echo Geek Guy's sentiments here... a cage is designed to protect you in the event of the worst case scenario in motorsports (a high speed rollover with impact into a stationary object). It's not the place to skimp on price, or to use as an experiment to learn how to weld.

Safety equipment is designed and built by professionals with years of experience in their fields. It's tested, there's very rigid QA standards, and the assembly path is tirelessly monitored.

Sure, you could build a set of harnesses out of some nylon or kevlar webbing. You could also make a helmet with some foam carving and some fiberglass. But, most reasonable people realize that the money that goes into these items pays not for the raw materials (which are very cheap), but for the experience of designers, certification, reliability, and the peace of mind to know that you have the best protection you can buy protecting you from the worst.

Cage design and welding is a complex process, involving a great deal of trial and error, practice, and experience. It resembles an art much more than a science.

If your design and welding isn't fully up to snuff, the least that can happen is that your cage will be blacklisted by scrutineering, and you won't be able to participate in events until the fault is remedied. The worst possibility is that something deeper, like a bad weld that looks good on the surface, will fail when you need it most, and you will be maimed or killed.

Don't fool around with this stuff. Find a reputable welder with experience building cages, preferably in your model of car.

My $0.02,

/Andrew
Recce01 03-18-2003 12:12 PM

RIGHT ON!!!
Dive in.....go for it....but it is not easy!!!!Trust me...There is some good information on caging a wrx to be found in this thread covering the build up of the Car Audio Gravel Spec Impreza. Pay no attention to the plastic models....as they were just a joke!! I dont know about the whole seam welding thing.....we didn't get that carried away!!I can however tell you that it is next to impossible to remove the "Quacha" from inside the seams, making welding them w/o acid dipping next to impossible!! 1 more piece of advice, every one with a tubing bender and a welder is a master fabricator.....so beware, its your life on the line!!!



[url]http://forums.nasioc.com/forums/showthread.php?s=&threadid=175559&highlight=hey+guys+check+this+out[/url]
elgorey 03-18-2003 01:53 PM

buy a copy of the SCCA GCR from SCCA.org. This will outline the required tubing types, diameters, and thicknesses. As well as what bars are required where, what needs to be straight, allowed bends, etc. (a similar, free, online document is available from NASA at nasaproracing.com)

Look up pics of cages for SCCA cars like [URL=http://www.improvedtouring.com]Improved Touring[/URL] cars. People like to show off thier cages, this will be an excellent starting point for your cage. Surf the improved touring forums and ask questions.

You will have to meet these cage specs if you plan on racing the car (and why else would you put a cage in it)


one suggestion though - if your car is your baby, then dont turn it into a racecar. racecars get bent, scratched, torn up, rubbed and generally abused. If you cant walk away from your car in a wrinkled heap, you should not be racing.
thebusiness999 03-18-2003 07:08 PM

Thanks for the responses guys. I basically want the car as raced out as I can have it while keeping it a street car, since at this point it still is my daily driver. I know it will be compromised as a full on race car as well as a comfortable street car, but at this point I'm willing to do this. Let me explain myself a little further...

While I'm not a very competitive driver quite yet, this sort of driving is in me and my car's future. When I first got my car (June 2001) I had a lot of fun off road, but have since cut back on my off road activities out of fear that the constant beating will be wearing out my chasis pretty quickly...I already felt it happening and that's why I've all but stopped. I can't help but go play in the mud after we get some good rain :)

We were originally going to strip the car and only seam weld it for the added stregth, but we figured if we're doing that much work we might as well get a cage in there too...I was planning to do this down the line, but if the car's apart, why not do it now.

Admittedly I do spend a lot of time in mountain roads late at night and go to track days whenever I can afford it. The added safety of a cage is well worth it to me. I'd rather not die if I find myself tumbling down a cliff or in a big accident at the track. Since this car is my primary mode of transportation, I'm looking to build a cage that will protect me and stregthen the car, while still keeping the car convenient and safe for the street (I don't want myself or my passenger to become vegetables either). I'm sure I'll get flamed for this, but all I'm asking for is some feedback and insight to help me reach my goals with this car.

At this point, my buddies and I think we can built a decent cage that will leave enough space in the cabin of the car to keep me and my front seat passenger safe from banging our heads against the cage in the event of a collision on the street. I've seen it done in a GC8 Impreza, so I imagine I could pull it off in this car too.

I still haven't decided how important it is to have this be SCCA legal because if I did do some real SCCA racing (ie. ProRally), I'd probably use a different car...I imagine the WRX getting pretty expensive to race at such a competitive level. Of course if I could build the cage under SCCA rules, while still keeping it reasonable for a street car, I'd do that.

About my car being my baby...I only meant it in the sense that whatever I do to it in terms of modifications has to be done 100% right. I'm not afraid to scratch it and bang it up. The only panels that haven't been damaged in any way are the roof, rear driver's side door, trunk, and rear driver's side quarter panel ;)

Scott, I'm very familiar with your the thread on your cage build up. It's a bit of an inspiration for this whole project. If it's not too much trouble, I'd like to meet with you and talk about this project. Since you have done this yourself, your insight would be much appreciated.

Once we start this project, it will be our focus and we expect to get it done in less than a month (hopefully less...we will be working on it pretty much everyday). I have the Subaru shop manual for the WRX, so stripping and rebuilding the car should be a little easier. Am I on crack by setting a month for the time goal?
lstepnio 03-19-2003 11:06 AM

I'm not a expert in this area but I have looked into this myself and almost every person with experience strongly advised against having a cage in daily driven vehicle for the same saftey reasons you have already mentioned.
Tkacik 03-19-2003 12:09 PM

Unless you are going to wear a helmet while you drive, I wouldn't suggest a cage. If your car was ever to roll, your head wouldnt be protected from the bars in any way. I thought about this a while back also....just too many drawbacks.
Recce01 03-19-2003 12:18 PM

I agree to a point
If your cage is well padded and you dont become laxed about wearing 5 points I believe it can be safe. It also depends on how the cage was constructed. Most cage work I see sits about 3" from the body shell and very close to the occupants, at that point I definetely agree. I tried to build my cage as close to the body as possible just for this purpose. Scott G.
the gravel crew
ChrisDP 03-19-2003 03:06 PM

SFI-rated padding is intended to keep a helmet from splitting open on a bare metal tube, not a head. The cheap padding I've seen referred to as "useful for soaking up blood when your head gets cracked open".
thebusiness999 03-19-2003 04:21 PM

As stated earlier, the cage will be designed to be as close to the body of the car as possible in order to minimize the risk of injuries like that.

I was planning to do most of the reinforcement in the rear of the car, where me and my passenger's heads would be relatively safe from impact with the cage. While there would be some reinforcement up front, it would be as close to the body as possible and no where near as extensive as the cage in the back. I don't mind if I lose the little plastic covers on the A pillar or the liner on the ceiling.

Once the car is caged I'll have no problems about using a harness (strapped up tight) on the street...it's safer anyway. Question for you Scott- How much of a bitch is it driving around in a 5-pt harness all the time?

I'm still researching the possibilities and weighing the advantages and disadvantages of this. If it proves to be too difficult or dangerous I might just pick up the STi or Cusco cage and weld it in while we're seam welding the car. IIRC, neither of those cages take up too much passenger space; either option should be reasonably safe.

Paul
[SIZE=1]doesn't want to be a vegetable[/SIZE]
Geek Guy 03-19-2003 04:50 PM

I think the general rule of thumb is as follows:

Anyone that is truly into motorsports (i.e. racing their scoobies) will tell you to only put a cage in the car if you are doing competitive events, and it's not your daily driver. It's just not worth the additional risk of having your naked head whap a bar (or have a bar come loose from a poor weld!) and you'd end up a vegetable. I'll gladly show you scuff marks on the helmet of our team's driver from the rollcage.

Do this instead:

Clubrally is cheap to get in to. Buy a clubrally car used from someone and play in the dirt in an organized manner. The *last* thing the rally community/Subaru community needs is a fatality of a rally nut with cage in his car playing around in the woods and killing himself or someone else on the street. My insurance doesn't need it, yours doesn't either.

I don't want to see people get injured from playing around. *Yes* it's good to have protection, but if you're race-prepping a car, it become a race car. There's a reason that the STi and Cusco cages are not SCCA/FIA approved...

I dunno - it's your car, but with our professional team, every dollar spent on safety gear is a dollar well spent. Our cage for our GC8 cost $4500... then the Sparco seats, and the belts, and the emergeny-pull fire-suppression system, battery cuttoff, etc... the list goes on and on.

Safety's not something to do halfassed, and in this case, something that you think might make you safer might end up hurting you more!
AJS 03-19-2003 05:06 PM

My Opinion
Group

This is solely my opinion based on my experiences.... I�m sure some people won't agree...

Reality - Take your time and cash budget, your reasonable estimates, and multiply both by three. That�s a realistic estimate of how long it will take and how much it will cost.

Do not��.I repeat, do not build your own cage!! Building a safe cage is a science, not a weekend hobby!

Analogy: I'm an auditor but I want to build my own house. I can swing a hammer just fine. I can also play with modeling software to design the darn thing but there's no way I can draw blue prints for it, I'm not a structural engineer. Just because a wall looks like it's strong doesn't mean it can handle various loads placed on it from varying angles! My house would fall down in the first earthquake.

Find a certified welded that builds cages for a living. If you can find someone that has FIA approved cages and can show you documentation regarding his weld penetration x-rays etc. you're in good hands. I'm not trying to scare people but your life depends on it. I know mine's worth more than the $1K or 2 you'll save by doing it yourself.

As far as cages being safe for the street e.g. hitting your head etc. I don't see a problem if the cage is built properly and is tucked tightly against the A pillar. My cage basically touched the A pillar all of the way up and hugs the roof. It only sticks out the diameter of the tubing, like an inch and a half. If my head hits the roll cage it would have hit the A pillar so what's the difference? Your skull will crack either way and if you think one piece of metal will do more damage than another, then throw a pad on it.

Seam welding: This is no easy task and I don't think I'll do it again. I'd rather pay someone else to do it or get the chassis completely acid dipped. It's a real pain!

There's no need to seam weld a streetcar. You may as well write the car off because it's basically totaled once you start welding. The heat applied via seam welding will twist the chassis. There are techniques to minimize this but you'll always have some chassis movement. Your doors will never hang right again and your alignment will need to be corrected. It�s really not worth it for a streetcar.

I have some pictures of my Group N car getting seam welded on my web site. See the link below. These pictures were taken over a month ago and we�re still working on it. The project started in early November. GT Fabrications as almost 100 hours into the chassis and I have at least 100 hours into it of my own time and it�s not done yet. I think the chassis will be over 250 hours of labor, easy. I work 50 hours a week at my day job and at least 20-30 hours a week on the racecar. I�m life is on hold until it�s done. Is it worth it�that depends on each individual person.

Check [url]www.universalrally.com[/url] for some pics. There�s no text but the pictures should give you an idea of how to properly seam weld a car.

Have fun�..
Recce01 03-19-2003 05:51 PM

5 point driving
Paul,
It's actually rather difficult to drive around in traffic strapped up tight, I am getting some special mirriors just for this issue. I will keep you posted as to what I come up with.
Everyone else,
How do all those rally drivers drive from stage to stage on the street w/o their helmets on ? Is a rally car not supposed to be a street car? Maybe I missed the boat on this one....more info please......I enjoy my car as much on the streets as I do on stage!! That's why I did a rally car vs. a desert race car!
subyguy2 03-19-2003 06:12 PM

Honestly, unless you plan on "racing" your car (not HPDE), seam welding and a full cage is rediculous. You do not need seam welding for a street application, nor do you want the pillar bars for the cage to make contact with your head. Even with a desigen which allows the pillar bars to keep as tightly against the body as possible, you are forgetting, that in an accident, lots of things move, you, your seat, the car, making it entirely possible that your head could still smack into the bar. Especailly without useing 5 point harnesses all the time. So my recommondation to you is to not seam weld the car (a waste of time for a street car, even if used for HPDE), and just go have a PROFESSIONAL shop build you a 4 point roll bar which is all you need for street/occasional hotlapping(HPDE) car. Do you really want to risk your life on the street that badly with a cage, I wouldnt. You should not make the cage or a bar without plenty or prior knowlege and experience in doing so, since your goal is safety. A badly built cage can be very dangerous, it is not allways a better than nothing scenario.

Chris.
thebusiness999 03-19-2003 06:21 PM

Once again guys, thanks for the responses...they're exactly what I was looking for. I'll be honest, I don't know what's going to happen now. While I'd love to jump in and do this, I still don't know for sure if we can handle it and do this safely. I'm going to talk to some more people about the cage issue and also find out more about the welding skills of the people who'll be working on my car. I got a bunch more questions though.

I am aware that the STi and Cusco cages aren't SCCA approved, and I don't mind that. The primary purpose of the cage was to stiffen the car and give me a little more safety incase I do find myself tumbling down a cliff :eek: . If I go with either of these cages, we will be welding them to the A, B, and C pillars, as well as to all the mounting points on the chasis itself (along with some further reinforcements where cage meets the floor). I am also considering welding the joints where the cage bolts together once we have it in the car. I figure if I go with one of these cages I might as well get the most out of it. These modifications should make a pretty big improvement, shouldn't they?

I thought my car could benefit from a little bit of race preparation since it did/does take a beating fairly regularly. I figured that by seam welding the chasis, my car just might last a little longer under the abuse it gets.

Can someone clarify why and how exactly seam welding it will twist the chasis? If the chasis twists, wouldn't that change the handling characterisitcs of the car to less than ideal? It appears that seam welding would make it tougher for a racer to be the fastest if the chasis is no longer behaving as it was originally designed to...kinda counter productive. That aspect of this argument doesn't make sense to me.

I apologize if this is just plain stupid, but do you guys think there would be a benefit from seam welding certain crucial areas of the chasis rather than everything on the car? Like maybe just covering the most important areas that do take a beating when the car is off road? By doing that the car would get some additional strength and possibly not tweak the chasis as much (?). There must be some way to do this without tweaking the chasis and taking as much labor. Is it safe to assume that only strengthening certain parts of the chasis will stress the non-strengthened parts more?

Like I said before, this car is my primary, daily driven car...when I'm ready to have a race car, I will buy something else that won't be as expensive to race. Of course I'm well aware that the race car will have to get a certified SCCA approved cage (I hope you don't mind me hiring you to build it Scott ;) ).

I think I've rambled enough for now.

Thanks in advance,
Paul
subyguy2 03-19-2003 06:25 PM

If it is your street car, then you do not need a full cage, a 4-point bar will be just fine, all you are doing is adding risk to yourself.

Chris.
dwx 03-19-2003 06:49 PM

I don't know anything about seam welding the car but this is probably sufficient for additional safety for events where you may be wearing a helmet, and guys on here are already using them in their cars. I myself ordered the race rollbar with the removable harness bar.

[url]http://www.ioportracing.com/Merchant2/merchant.mv?Screen=CTGY&Store_Code=IPRS&Category_Code=AP805[/url]
Recce01 03-19-2003 06:58 PM

OMG
Paul,
I cant post that......nevermind, and for those of you that read it before this edit, I am sorry if I offended you, IMO...the above mensioned link is not good for a wrx, a Pinto..maybe
thebusiness999 03-19-2003 07:16 PM

Damn...missed the (what I'm assuming is) **** talk :lol:

So why you so against these Scott? You can PM me if you don't want to be public about it.

Now if you guys are telling me not to weld the cage myself, why would I want to get a U-Weld kit?
Geek Guy 03-19-2003 07:35 PM

To address the issue of what-to-rally-drivers-do-between-stages question: It's pretty darned simple. Drive under the speed limit, quite carefully. Sometimes they wear their helmets if it's a short run. They knowingly realize it's a danger to go without helmets. They don't go out and spank the car on public roads (or even semi-public). It's CLOSED roads when they race, open roads when they transit. They are ambassadors to the sport. They get penalized (exluded!) from the race if they do something stupid on transit.

If you want to stiffen the car (and you're finding it sloppy), I'm sad to say that the damage is already pretty much done. Seam welding a sloppy car at this point is going to make it twist even more, unless you can seam weld the same spot on all four corners at the same time. We seam welded our GC8 at the same time we were putting our cage in, and this is after the car was a grocery-getter for 80k. It was not an easy task... (btw, the guy who did our cage is named Brent Hatch, of Hatch Engineering. He's in Vermont, I believe.)

In order to seam weld underneath, you have to wire-brush off the locations where you're going to weld. And it has to be VERY clean. We did the underside of our car after a few events (just did the inside and some outside when the cage was done) and it was a pain in the butt to get that stuff off. And we have a floor lift, and had a local professional welder come in and do the work!

You can't undo age to a car. You've prematurely put on about 8-9 years on the chassis by pounding it for the last year w/o tightening. If you want to tighten it, put in front and rear strut bars, front and rear sway bars, stronger endlinks, better suspension, etc. is the safe way to go.

Go ask questions like this over on specialstage.com in the Car Construction forum. Just to warn you, they may totally rip you apart. That's the way of the rally circle here in NA.

You can't half-build a racecar.
dwx 03-19-2003 07:55 PM

Re: OMG
[QUOTE][i]Originally posted by Recce01 [/i]
[B]Paul,
I cant post that......nevermind, and for those of you that read it before this edit, I am sorry if I offended you, IMO...the above mensioned link is not good for a wrx, a Pinto..maybe [/B][/QUOTE]


What is wrong with Autopower roll bars? I know others that use them in a variety of cars, and have heard stories of how they worked the way they were intended... You can PM me if you want. Their cages are all approved for SCCA/NASA/etc. club racing... I've even seen NASA pages that recommend using their rollbars, especially in convertible cars.
ChrisW 03-19-2003 08:02 PM

thebusiness999,

if your determined to put a cage in your car check out and or talk with Paul Eklund [url]http://www.writerguy.com/primitive/index.htm[/url]

he has a rollcage kit, [url]http://www.writerguy.com/primitive/body.htm#rollcage[/url]
randy zimmer 03-19-2003 08:41 PM

too much work
Sounds like too much work to me.
Here's the deal.
I'm on my second chassis in two years of almost weekly rallying.
The first was a 96 and bought (like I was told to and it was the right thing to do to get involved in the sport). It had been a straightened wreck and had a crappy cage that was no where near what I wanted. The car was not reinforced, seam welded and didn't have a front tie bar. The only parts that moved after running it were the front towers until I made a simple brace. The car is still as straight and strong as when I put the tie bar in after much, much abuse.
I built my own car out of a '93 and put in a nice cage.
[url]http://www.randyzimmer.com/video/subycage/[/url]
It is only connected at the windshield pillars. I left it unwelded at the B pillar on purpose to see what would happen and it squeaks a little but nowhere near what I thought it'd do. This car is also not seam welded and is perfectly straight after a year of rallies. There are no stress cracks or other damage.
My findings?
The part that collapses on these cars when rolled over is the roof at the A pillar. A roll bar will not help that. A roll bar will strengthen the strongest part of the car already, so it is really just weight. My cage is as close to the roof as it can be over the door opening, I hit it with my head.
If I were you, I'd put a tube from the foot box up to the top of the A pillar to triangulate the A pillar opening, just a 7/8 to 1" .083 but with nice mounting plate points to spread the load.
[url]http://www.randyzimmer.com/video/subycage/havir1.jpg[/url]
This would make you move your legs to get in and out but help the weakest part of the structure. This and the front tower tie bar should keep the car pretty straight.
problems? knees and hands will hit it and also the getting in and out thing.
----
re: Welding bends stuff. To align things, an accepted way is to run beads on one side, it sucks in and bends the piece.
----
re: road transits.
It helps to have 4 eyes in the car. Intersections are frightening with a helmet on and belted in. I don't recommend it for everyday use.
----
what you propose to do is too much work.
also, practice on a less ambitious project that isn't worth so much.

rz
Recce01 03-19-2003 08:46 PM

Auto Power
Auto power roll bars are just fine for some applications.....Rallying is way too abusive for a cage that is not attached to the uni-body in many locations(IMO). I have seen many Auto power kits and to be quite honest , I am not very impressed with the design...not that I know what the hell I'm doing, but I dont like seeing a cage that is three weeks from the body shell. A friend of mine went that route, every time we hit a bump, you could see the cage moving around inside the car......literally!That sort of thing scares the hell out of me!! I also dont care for the slip-fit-bolt-through-sleeves that are in the kits that I've seen. I am way paranoid coming from the off-road racing arena, and compare Autopower to what I have seen from Smittybuilt.........functional....I guess, but not the best option. The cage work is best if it doubles as a major chassis stiffener, I dont feel that the Autopower cages accomplish this. I guess all in all, you get what you pay for, and the Auto power cages dont cost 4-5K, so maybe I shouldn't complain. I know Paul and would like to see him in something a little more stout than the Autopower kit! Just my Opinion...hope I have not offended anyone too badly, as it was not my intent!
dwx 03-19-2003 09:48 PM

Re: Auto Power
[QUOTE][i]Originally posted by Recce01 [/i]
[B]Auto power roll bars are just fine for some applications.....Rallying is way too abusive for a cage that is not attached to the uni-body in many locations(IMO). I have seen many Auto power kits and to be quite honest , I am not very impressed with the design...not that I know what the hell I'm doing, but I dont like seeing a cage that is three weeks from the body shell. A friend of mine went that route, every time we hit a bump, you could see the cage moving around inside the car......literally!That sort of thing scares the hell out of me!! I also dont care for the slip-fit-bolt-through-sleeves that are in the kits that I've seen. I am way paranoid coming from the off-road racing arena, and compare Autopower to what I have seen from Smittybuilt.........functional....I guess, but not the best option. The cage work is best if it doubles as a major chassis stiffener, I dont feel that the Autopower cages accomplish this. I guess all in all, you get what you pay for, and the Auto power cages dont cost 4-5K, so maybe I shouldn't complain. I know Paul and would like to see him in something a little more stout than the Autopower kit! Just my Opinion...hope I have not offended anyone too badly, as it was not my intent! [/B][/QUOTE]

I would agree I wouldn't use one of their cages persay I'd use something with a bit more to it that was welded in. If I was building a racecar I likely would go with something proven for rally use built by someone who has done it before. TAD Motorsports locally has welded in some cages in a couple Subarus and it's very good work.

Randy, is that a picture of Doug's car after the rollover crash? Prodrive probably has a good idea of what they are doing. Man that's alot of CF...
randy zimmer 03-19-2003 10:10 PM

doug's car
Yes that's Doug's.
I was very proud of my cage till I saw Doug's. It was overwhelming in its design, of course it is an FIA cage and we couldn't submit such a wild design to SCCA and have it OK'd.
It did the job, it even took the full force of a tree at the "weak point" and tore but held up good enough - didn't it!
I used that pic to show the vertical bar I proposed for Biz' beater.
I wish I had a picture of the Montero that totally collapsed when it rolled. Good thing Sumit is short, it would have killed him if he were taller.
rz
thebusiness999 03-19-2003 10:24 PM

I've seen one of the Autopower roll bars at my local WRX meet. It looks pretty beefy, but it does sit really far away from the body shell...maybe a bit too far away for my tastes.

The Primitive cage sound like a nicely priced option but at 1.75" thick, it'll probably put my head at a higher risk than I'm comfortable with. Anyone have pics of this cage installed?

I know that whatever I end up putting in there will have to be attached to the pillars if I really want to stiffen things up. IIRC, I don't think I'd be able to do this with the Autopower. From what I've seen of the Cusco cage, I could attach it fairly easily. The only problem with the Cusco cage is its A pillar reinforcement (or lack of). Do you guys think it's possible to do Zimmer's A-pillar modification to the Cusco (or Primitive) cage while still keeping the cage strong? I imagine cutting and welding will compromise the rigidity of the structure.

Zimmer, do you have any more pics or details you can share about the triangulation at the A-pillar? I'd like to use that kind of design when I go through with this project.

I still have a lot to go over before coming to any decision about the cage issue. One thing's official: I think I've been talked out of seam welding...maybe it is a bit too extreme for my lowly street car. I'll save that for if I fall into a large sum of money and can pay someone to do the work for me.

Thanks for the concern Scott :) Judging by what you've done with your car, I'd have to say you do know what you're talking about. Hopefully we'll get to discuss this a little more at the Rally X this weekend.

Edit- That yellow car is NUTS!!!
randy zimmer 03-19-2003 11:46 PM

rewind
Biz,
I don't think you got the point, if you want to drive around town and also goof off, just support the roof (period).
Look at Doug's small bar that goes from floor to roof and find a way to do that ONLY. A cage in a road car is not needed and will cause more problems than it solves.
These cars are stout in almost every direction. 3 days, $100 and you're done.
rz
thebusiness999 03-20-2003 12:36 AM

I got your point, but I don't trust the car's roll over protection as much as you do. I still don't know if I'll do a full cage yet because of these safety issues, but I am taking note of everything I read here and on special stage. I also know that the use I get out of the car does put me at a higher safety risk than most other cars on the street. If doing this A pillar brace will give the car enough strength and protection, then maybe I can get by and feel comfortable without a cage.

I do agree with you that the A pillar is probably the weakest point of the roof structure and that will definitely be addressed. It looks like this kind of A pillar brace could be fabricated pretty easily. I can already see how I'd get it securely attached to the middle (possibly top) of the A pillar without being much of a safety risk to my head.

I'm curious about where ideal placement for the base would be...do you have any more pics of this part of the cage? I could probably figure it all out once I have the car apart, but any insight from the pros would be appreciated.

What material would you recommend I use if I only do the A pillar brace? I don't mind paying more for something strong and light since this will use very little material compared to a whole cage.

Thanks again for your time...
tifosi77 03-20-2003 03:23 AM

Okay I thought that I would chime in here, to seam weld a car is a very labor intensive effort, you will need to strip the car completely (I mean no paint) to do this you have a couple of different choices, acid dip (this will eat some metal but will provide yo uwith a beautiful shell to seam weld), plastic Media blast(this does not eat metal, fast, clean, cheap), bead blast (damages metal but very effective but not in seams), nitrogen freezing (clean and apparently very effective even in seams downside is it takes a little finesse but also cheap), and wire wheel. The problem of seam welding a unibody car like the WRX is all of the seam sealer that the manufacturer out in between the plates it will bubble out and contaminate you welds which renders them useless. Acid dipping removes this seam sealer and thus this is the choice of the Subaru World Rally team. Nitrogen freezing does something similar but you just blast a little (I stress little or you will crack the metal) wait till you hear the seam sealer crackling and tap with hammer and it will drop out, plastic media blasting you will need to pay for but for 650-1000 you can get hte entire car stripped and the seams chiseled out not quite as thorough as the other two but very effective and reccomended by a lot of Porsche racing guys I know, you also have bead blasting but it is just a primitive type of media blasting, last option is the wire wheel it does a decent job but if yo uare going to all the trouble of seam welding the car you might as well do a great job and either dip or blast the car. After choosing that method you will have to totally disassemble the car I mean wires glass, doors, fenders, everything until the shell is totally naked, next blast or dip, and you are ready. You will need a erson that has been welding a very long time with a good mig welder that will keep everything cool without overheating and thus warping the car. YOU DO NOT NEED TO WORRY ABOUT WARPING THE CAR IF THE WELDER KNOWS WHAT HE OR SHE IS DOING (sorry for the caps but I wanted to emphasize something that is a bit of a wives tale the result of very poor weld jobs) you should use .035 wire and run a .5 inch bead every 1.5" on every exposed seam in the car. This will take a lot of work. It will help if you also have built a car rotisserie thing (there is a picture of one on the universal rally website. Next will be your cage DO NOT FAB ONE JUST SPEND THE CASH AND GET ONE MADE FOR YOUR CAR, for the WRX you can get a fab one from prodrive that will be pre-bent all you have to do is assemble an weld into the car it is about 2300 bucks, there are others like one AVsport will sell that is about 1300 dollars that is also FIA approved (get the papers with the cage it will be worth it in the long run if you plan to rally) for the GC8 there are more choices like one from OMP, Sparco, and Safety devices (all of the aforementioned cages are weld in) they run between 600-1100 depending on shipping. these cages have been designed with care and will fit the body real nice. I would reccomend that you also weld in a tube on the door sill that is where a lof fo damage occurs from rocks and tree stumps. I would tell you that you should TIG in your cage and do not buy a Chromoly cage since they are very hard to weld (you need to normalize all the welds and they can be more fragile) . If you want you can tig the cage first and then seam weld this will reduce the cahnce of warpage. No offense to anyone else but i have robably spent more time on this subject then most since i am building a true FIA homologated Group N car so I have spent an eternity looking at all of this. Seam welding will really extend the life of a rally car if it is on the street it may be a bit much. If you ever tap on the floorpan of a seam welded car you will feel how much more solid it is then one that hasn't been. I have no idea where you are located but I can provide you with contacts for plastic media blasting, acid dipping, as well as where to get a cage. i would tell you that if yo uare going to do it do it right and unless your buddy is a real professional with a lot of welding experience do not let him do it for you. Just striping your car will show how much more work it is than you thought. Enjoy and you can email me anytime if you have questions.

Jeff
Club rally Car #389
mlambert 03-20-2003 09:00 AM

wow thats a long hard to read paragraph
HoRo1 03-20-2003 10:28 AM

Going for the big one Paul?

As long as everybody knows what he/she is doing and they have the right equipment and you can handle the inconvenience of the cage (hard to get in and out, messed up dash etc) and the fact that the resale value of your car will halve immediately...then go for it.

Personally, I wouldn't do it. As you say, your car is your baby.
HoRo1 03-20-2003 11:34 AM

[QUOTE][i]Originally posted by thebusiness999 [/i]
[B]
While I'm not a very competitive driver quite yet, this sort of driving is in me and my car's future. When I first got my car (June 2001) I had a lot of fun off road, but have since cut back on my off road activities out of fear that the constant beating will be wearing out my chasis pretty quickly...I already felt it happening and that's why I've all but stopped. I can't help but go play in the mud after we get some good rain :)
[/B][/QUOTE]

I wonder what you're talking about :D

Proceed carefully. Talk to cage builders. Go to look at as many cages as you can - see what they look like, good points-bad points etc. When I went to Tripoint in Canoga Park and was discussing cages with them - they build the Speed Challenge Mazda Proteges - they told me that Chromoly tubing was overkill, over-priced and over-weight. A cage will add a good 200+lbs, maybe 250.
thebusiness999 03-20-2003 01:01 PM

I spent a few hours last night researching cages and seam welding on specialstage.com and all I can say is I'm glad I didn't just jump into this. I admit I was not aware of how difficult or expensive preparing a chasis for seam welding is. I know stripping the car is a bitch, but it's pretty straight forward; it's removing the seam sealer that really turns me off to doing it myself. It'll definitely be too costly of an undertaking (in both time and money) for me to engage in right now.

With everyone insisting that I buy a cage, rather than design one from scratch, I don't know what'll happen with that now either. This whole idea came to life because we thought we could save some money and have some fun by doing this project ourselves. We love working on cars and my buddies are nuts about fabricating parts (and pretty capable) so a cage seemed OK. This whole plan might have to be put on hold for now, but I haven't come to that decision quite yet.

Jeff, I'm located in the SFV. Could I check out your car sometime? If you want to hang with some Subaru guys and talk cars, we're meeting at Flames on Canoga and Plummer tonight (and every Thursday night). It's usually good to show up at about 9:00...the only thing that will cancel the meet is rain.

Yes Howard the car's my baby, but you know how I constantly beat her. The car and myself could probably use some more protection. As you can see this whole issue is now a bit more complicated. I don't know what's going to happen anymore. I'll tell you one thing, I'm glad we didn't start this project over winter break...what a disaster that would have been :lol:
tifosi77 03-21-2003 12:49 AM

Hey I was in that area but was at a corporate event for work all day, drop me an email off the boards with your number and I will call you. I am running Rim of the World in my Toyota which I am driving while I slowly finish my subaru you will be able to see how much work is involved in stripping a WRX since I do not have sound deadening, seats, airbags, door panels, interior trim except fo the dash, air con, no headliner etc etc. I can also show you some other rally specific stuff that i have found. hell if you want to get into rally for not too much money I know of a couple of good cheap rally cars that are ready to race. Just let me know I am always willing to help.
FuJi K 03-21-2003 02:42 PM

Time to look at some cage designs!
[url]http://e30m3performance.com/tech_articles/cage_symposium/cage_symposium.htm[/url]
Alleggerita 03-23-2003 06:18 AM

[QUOTE][i]Originally posted by HoRo1 [/i]
[B]

they told me that Chromoly tubing was overkill, over-priced and over-weight. [/B][/QUOTE]

Chromoly may be more than you want to spend and too much of a hassle to fabricate but the weight difference is huge - it is way lighter and stronger than mild steel.

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