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Discussion Starter · #1 ·
I posted this in the old forum but all that is gone before I could get the anwers I am looking for. I want to either buil my WRX into a PGT car with ability to bump up to group N in the future. Now I am deciding on the cage and I know about Avsport, Cascade, and Vt car but I live in So Cal and wanted some recomendations on cage builders. Secondly should I have the cage built to FIA specs since from what I have read on these forums people say the SCCA rules are a bit tricky. I have ordered the rule book but it hasn't arrived yet. Last what material sould I choose Chromolly (I hope I spelled it Right) or I believe the other is DOM. Also I have tons of pics of cages so I can find a good race shop that could build off of those I imagine or should just order one from the UK like safety devices or Sparco? Thanks in advance for any advice you people can offer to me.
 

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There are several commercial FIA certified Group N cages available for the WRX. I would suggest going that route if you are indeed serious about Group N. The cost is not necesarily cheaper since the cages must be imported but you have that little FIA sticker and you have a reasonable expectation of decent quality.
 

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FIA rules a pretty tricky, so I'd either mail order a cage in, or go to one of the pros. On the west coast, 3 come to mind. Dave Clark Motorsports, Cascade Autosport, and AV Sport. All do good work, and understand FIA rules. The hassle of driving a day or two to another state to get the proper work done more than outweighs the hassle of trying to make a local fabricator understand what needs to be done.

Dennis Martin
[email protected]
920-432-4845
 

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Discussion Starter · #5 ·
What about the material issue? would you guys say DOM is better since you don't have to normalize the welds?
 

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My reading of the FIA rules indicates that a regular mild steel is the only material you can use if you are building your own cage. Many of the homoligated cages use T45 but they are certified by the manufacturer. Buy the cage from Saftey Devices or PRODRIVE and then have a reputable Rally shop install it. It won't be cheap but you are rallying a $20K car so money can't be that much of an object.
 

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Discussion Starter · #7 ·
Anyone know how to conyact safety devices? I think I remember that they have a USA distributor in the midwest but I cannot remember.
 

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>What about the material issue? would you guys say DOM is
>better since you don't have to normalize the welds?

DOM is not a material - DOM stands for Drawn Over Mandrel. The steel bar is basically forced over a big spike so you get a tube without any seams. Some seamed tube is called ERW - for Electric Resistance Welded - made by wrapping a sheet into a tube and zapping the seam.

Chrome-moly is steel with significant amounts of chrome and molybedenum which allow for increased strength by heat treatment - but without proper heat treatment it can be quite brittle.

Mild steel isn't as strong as chrome-moly, but doesn't need any heat treatment. When you take into account the thinner wall used in a chrome-moly cage, a mild steel cage should be just as strong and just a few pounds heavier - not enough to make a difference.

I'd recommend Dave Turner Motorsports in Hemet CA (not roadracing D T Motorsports in San Diego) for cage construction. He generally does make his cages out of chrome-moly BTW. Sorry, I don't have his #.

Tom Bier
 

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You said you were in southern california, so I will tell you
about southern california cage builders. Roadrace Engineering
recently did a Subaru WRX. You always get a safe cage there.
Dave Turner in Hemet also builds cages that are well done.
Bob Scott in Montrose is smaller but also does good work. Ron
Wood at VW Specialties in Huntington Beach also does nice work.
He also in charge of certifying your cage as local tech inspector.

All of these people understand rally cars and the SCCA rules very
well. Don't get some roundy round builder to build you something
that will never pass SCCA rules, much less FIA.

FIA cages are a problem. You need to build the whole thing to
a approved design. The designs use metric tubing that is very
hard to get here. There are NOT many people who have even built
FIA cages in this country. If you want to leave that option open
perhaps you should start tracking down the proper design drawings
and tube sources.

Right now they are accepting SCCA legal cages in group N, but
in the future that could be tightened up...

Paul Timmerman
Competitor Liason CRS
 

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Discussion Starter · #10 ·
IF I wanted an approved cage for Group N can I just order an approved design from the UK? I have a lot of interior shots from the WRC car should I have somebody go off those? What do you guys think is best, order or custom? Thanks for all the help so far.
 

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>DOM is not a material - DOM stands for Drawn Over Mandrel.
>The steel bar is basically forced over a big spike so you
>get a tube without any seams. Some seamed tube is called
>ERW - for Electric Resistance Welded - made by wrapping a
>sheet into a tube and zapping the seam.
>

Tom,

Actually DOM is NOT seamless, technically speaking. DOM starts out just like ERW, flat sheet steel, but after it is rolled and welded, it is drawn over the mandrel. As the tube goes through and over the mandrels it is twisted, so the seam gets mished and twisted around the tube (imagine a paper towel roll core). For all practical purposes, the seam is gone.

There IS true seamless tubing, usually starts out as a 10" round, 3' long billet, that is pierced like a big fat straw. Then drawn over mandrels to whatever size you need. They are referred to as CDSM and HFSM.

Gabe
 

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I'm not sure building from pictures alone would be a good idea. There are specific measurements that must be complied with that you wouldn't know about from a picture other than general shape or location. Things like door apeture measurements and gusset requirements etc...
 

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Discussion Starter · #13 ·
I contacted Demon Tweeks in the UK and they said they can supply a homologated cage for 485 british pounds, this seems very inexpensive compared to some of the quotes I have recieved in the states is this too cheap? Is Demon Tweeks a reputable company? Can you guys give me some advice? Also does Sparco make good cages? I am also waiting for a quote on a Sparco cage?
 

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Deamon Tweeks can absolutely be trusted! Excellent reputation and knowledgable staff.

If the price includes shipping, that would be quite the deal. Something tells me it doesn't.

Tweeks is a retailer, so it is likely they are selling a Sparco, OMP or Safety Devices cage.

Is it a kit?

Cheers and good luck!
 

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Discussion Starter · #15 ·
Thanks for all the advice I think that my best option is to order one from demon Tweeks since that seems like the best deal.
 
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