darguy

Hey Gang

I'm in the planning stages of a full cage for my 99 FRC, which is in transition from DD through SoloSprint (Solo 1) into an Improved Production, CACC car (approximately Improved Touring in the SCCA). Racing in Canada, eh.

The CACC uses essentially SCCA rules with a few differences for IP/IT - but the cage specifications are the same. I'd like to build something that I could bring into WA and OR to run in the ICSCC series that also includes our local track in Mission, BC (SCCA-IT rules for cages in that series).

I'd also like to leave the door open to upgrading to GT specifications one day - and if possible, avoid significant cage reworks as a result.

I'm not super familiar with the racing regs beyond this for other series, and am open to suggestions/comments. Are there other GCR's that I should consult to cover the bases, should I decide to trave/compete elsewhere down the road?

travisnd

I'd take a look at the NASA book too. My cage is legal for NASA and SCCA. I specifically addressed that with my my cage builder. I currently run with NASA, but wanted the cage legal for both to leave my options open and to aid in resale should that time ever come.

darguy

Thanks for the advice - I'll look into the NASA regs and see if we can come up with a design that fits both organizations.

darguy

I'm dropping my car of at the Fab shop this weekend, we've got the design sorted out for the most part - but need to order the tubing. The question is, 0.095" or 0.125"? The CACC & SCCA spec is for 0.095", but NASA calls for 0.125". The estimate is for approximately 80 feet of tubing total, and at 0.573 lbs/ft difference that works out to about 46 lbs extra to go with the NASA spec.

I don't know that I'll need it down the road (are there tracks that require that over SCCA, like Laguna Seca or VIR for example). Or does it make sense to save the weight and limit my resale/race options in the unforseeable future?

Thoughts?

sspeed30043

It was suggested to me to go with .120 wall DOM, because eventually all series are going to be going with it. Then no worries about future rework.

Look up Bill32 , he gave me a few pointers


also check out this thread

http://forums.corvetteforum.com/auto...it-begins.html

drivinhard

Just to clarify that, NASA calls for .120 for over 3000 lbs (sans driver and fuel) So around 3250 or 3300 lb as raced (depending on what the driver weighs).

travisnd

Mark is correct. My car was light enough that I could have gone with .095", but the thicker tube only added about 35 pounds to the car and is exponentially stronger.

trackboss

I've used .095" on required tubing and lighter elsewhere. Next time around I think I would do the main hoop .120 and everything else as before.

Bill32

SCCA:
Material:
A. Seamless, or DOM (Drawn Over Mandrel) mild steel tubing (SAE
1010, 1020, 1025) or equivalent, or alloy steel tubing (SAE,
4130) shall be used for all roll cage structures. Proof of use of
alloy steel is the responsibility of the entrant.
B. Minimum tubing sizes for all required roll cage elements (All
dimensions in inches):
Vehicle Weight Material
Without Driver Mild Steel Alloy Steel
Up to 1500 lbs. 1.375x.095 1.375x.080
1500-2500 lbs. 1.50x.095 1.375x.095
Over 2500 lbs. 1.50x.120 1.50x.095
1.625x.120
1.75x.095

I recommend that before you hit the fab shop, go to www.scca.org and download the GCR , it's under "Cars & Rules" (free download).
In that large pdf, look at appendixes I and J.

I haven't raced in NASA for qiute a while but IIRC, their cage rules are almost identical to SCCA.

There are no special rules for Laguna, tracks let the organization take care of tech.

darguy

Thanks for the feedback!

Based on this, I've decided to go with the 0.120" (transposed typo error on my part with the .125 when looking up relative weights). The Fab Guy is ordering the tubing today. I've been comparing the three regs (these are the latest I could find):

- Nov 2010 version of the CACC GCR, Ap I: http://www.caccautosport.org/pdf/201...Appendices.pdf

- Nov 2011 version of the SCCA GCR, sect 9.4, pg 104: http://scca.cdn.racersites.com/prod/...ovFastrack.pdf

- Aug 2011 version of the NASA CCR, sect 15.6, pg 59: http://www.nasaproracing.com/rules/ccr.pdf

I'll be making some detailed notes on the design worked out so far, with the objective being to meet all 3 regs. It'll end up being more robust than any 1 requires - but that's probably a good thing.

I'd seen that thread - an awesome build, for sure. I wish I had that budget! We weren't planning on cutting out the halo bar or the a-pillars, but building right up to them. I've got the seat down low enough (I'm 6'1") that the clearance is OK without cutting that deep into the car.

But along those lines, now that the interior is out of the car it looks like the roof/back glass of the FRC would be pretty easy to take off. Can this be removed as an assembly without popping the front or rear glass out?

darguy

Was out doing some mid-cage measurements & consulting on some tubing placement options for the front down tube along the front glass frame & door jam.

Can I trim out this triangular gusset (aluminum, I'm guessing) to get the tube tighter in:

travisnd

I ditched the glass etc. and had the bars run in the slot left by the window trim etc. Cage builder did take the plasma cutter and trim the windshield frame some so he could position the down bar w/o having to cut any more of my door hing structure than I had already cut.

darguy

Hey Gang - I've been too busy with work & working on the car (and renos) to update, but I'll tie it all together here:

The 8-pt cage was completed, along with the seat install / belt anchors, fire suppression, window netting, kill switch, removable steering wheel & tow straps - with about 12 hours to spare before annual tech inspection late last month. Since then, I've done the rest of the normal race prep & repaired the cooling ducts - with about 12 hours to spare before Friday practice. That was last weekend - I've now got 2 races in it under my belt, but that's a story for another thread...

Before:



Fitting the main hoop (after removing the old roll bar...):



First go with the A-pillar bars, these would get tucked in tighter after the aforementioned carving took place:



Setting up the rear stays:



While everything was out, the kill switch wiring and fire suppression lines/nozzles went in - through the firewall with the other wiring, and tied into the main feed to the underhood & cabin fuse/relay panels:









CACC rules require a bottom x-bar between the A-pillar bars. To keep this away from my long legs (and shins), we had to bring the A-pillar down bars way forward and put the x-bar up under the dash:



With that done, the side-intrusion bar work could begin:



Another CACC requirement is 'foot-boxes' - bars going forward from the A-pillar down tubes to the firewall (or in this case, the frame by the firewall). Had to pull all the wiring/BCM out of the way, but was able to tuck it all back in afterwards:



Surprisingly, near the end of the job:





Timing was tight, this is Friday afternoon - last braces being welded in on the back while the glass guy installs the front. I'd have just enough time to paint before the rear glass went back in. I even made my dinner reservation that night:



And the nearly finished product, I had 8-hours of work left to button up the rest the next day before tech inspection:



No problems at tech, and I've now got my annual inspection done - just in time for the first event!

travisnd

Nice placement on the engine bay nozzles. I hadn't even thought about pulling the cowl and using the upper firewall like that. I made brackets out of aluminum flatbar, but I like your idea better.

darguy

Thanks, Travis. The glass & cowl were out and it seemed like a good spot - if I ever have to service them, it might be another story...

The rest of the fire suppression went together fairly well. We mounted the tank onto a bracket fabbed to go onto the passenger seat studs, and I ran a line up to a panel on the dash where I mounted the nozzle & one of the handles, and ran the other line back to the rear bulkhead:









I had an earlier thread going on the seat & wheel install - I'll update that with the finished product. The anchor points for the harness & the seat mounting ended up having to be done to some pretty tight tolerances to accommodate my height...