Time to remove any and all rubber from the car. Start with the dropping the sub-frame, pressing out all the stock OE bushings and/or powerflex, and replacing with Spherical. We also welded the sub-frame mounts on the undercarriage of the car as well as welded Turner Sway Bar reinforcement plates onto the sub-frame. Before and After shots of the bushings... :redspot

http://rgbtvinc.com/jpegs/sub0.JPG
http://rgbtvinc.com/jpegs/sub1.JPG
http://rgbtvinc.com/jpegs/sub2.JPG
http://rgbtvinc.com/jpegs/sub3.JPG
http://rgbtvinc.com/jpegs/sub4.JPG
http://rgbtvinc.com/jpegs/sub5.JPG
http://rgbtvinc.com/jpegs/sub6.JPG
http://rgbtvinc.com/jpegs/sub7.JPG
http://rgbtvinc.com/jpegs/sub8.JPG
http://rgbtvinc.com/jpegs/sub9.JPG
http://rgbtvinc.com/jpegs/sub10.JPG
http://rgbtvinc.com/jpegs/sub11.JPG
http://rgbtvinc.com/jpegs/sub12.JPG


While Bernie was working on the sub-frame, my lucky ass was squating inside the car for 4 hours with rolls of paper and painters tape. Watch the progress. First was an "acidic" base coat ( the army green color ) that etches the steel DOM rollcage ( 8 point weld in - Robinson Racing, Duluth GA ) Then a retape and a final spray. I chose pewter with a matte crackle finish. Looks very cool and classy.

http://rgbtvinc.com/jpegs/tape1.JPG
http://rgbtvinc.com/jpegs/tape2.JPG
http://rgbtvinc.com/jpegs/tape3.JPG
http://rgbtvinc.com/jpegs/tape4.JPG
http://rgbtvinc.com/jpegs/tape5.JPG
http://rgbtvinc.com/jpegs/tape6.JPG

AND FINALLY... Color!

http://rgbtvinc.com/jpegs/paint1.JPG
http://rgbtvinc.com/jpegs/paint2.JPG
http://rgbtvinc.com/jpegs/paint3.JPG
http://rgbtvinc.com/jpegs/paint4.JPG
http://rgbtvinc.com/jpegs/paint5.JPG
http://rgbtvinc.com/jpegs/paint6.JPG

This weekend, we bolt up the sub-frame, put in the SPA AFFF 5 point
fire system/bottle and nozzles, window nets, SFI Padding on the cage, then put it all back together again. Then we're off to Roebling with PCA in February...

More to follow...

Don't the rear down tubes need a 360* weld around the shock tower doubler - not the cross bar?

I'll pose it to Robinson Racing and see what they say. Thanks.

Jonathan

I'll pose it to Robinson Racing and see what they say.

You might want to show them this:

11. Mounting Points A.
The roll cage shall be mounted to the floor of the car in six, seven, or eight points. The cage shall not go through the firewall in Stock or Prepared classes. The seventh and eighth points must attach to the firewall or front foot wells solely for the purpose of foot protection. All cage attachment points must be mounted to plates. Each required cage bar shall terminate on a plate with a 360 degree weld to the mounting plate.

Now, I've seen people doing it the way it's done in your cage for years whether it appears to be legal in the rules or not.

Great find. I think that might be fixable.


Jonathan

You might want to show them this:



Now, I've seen people doing it the way it's done in your cage for years whether it appears to be legal in the rules or not.

I've seen GTS cars w/o rear down tubes running in NASA, they use only a rear X. I'm guessing they could care less how you do the rear tubes if that's the case.

Carlos.

I've seen GTS cars w/o rear down tubes running in NASA, they use only a rear X. I'm guessing they could care less how you do the rear tubes if that's the case.

A rear X doesn't meet the NASA requirements either, seeing as the BMW CCA and NASA cage rules are essentially the same.

There is a key difference in the NASA rules that I've highlighted below that is left out of the BMW rules I actually quoted above:

15.6.13 Mounting Points
The roll cage shall be mounted to the floor of the car in six, seven, or eight points. The cage shall not go through the firewall. The seventh and eighth points must attach to the firewall or front fender wells. All cage attachment points must be mounted to plates. Each required cage bar shall terminate on a plate with a 360 degree weld to the mounting plate, except as specified in Section 15.6.14.B. There shall be only one (1) mounting “point” per plate. This point is defined as where the “required tube” mounts. All additional tubes mounted to that plate must be mounted as close to the required tube as possible [Ref: (15.6.14.B)].

15.6.14.B Tube / Mounting Plate Specifications
Any number of tubes may attach to a plate so long as they are touching each other at the plate. There may be a small gap between tubes to allow welding 360 degrees around each tube. If there is no gap between the tubes, they must be welded around the base as much as possible to form a single figure-eight weld, AND the tubes must be welded to each other two (2) inches up from the base plate.

15.5.14.B still doesn't seem to allow a required bar to attach to the rear cross bar though.

dash bar looks a bit low...

get that finished so i can race ya. need more people in 3.

dash bar looks a bit low...

It's tucked right under the steering rack. I'd have to go custom to get it any higher.

Jonathan

It's tucked right under the steering rack. I'd have to go custom to get it any higher.

Jonathan

Have them redo it when they do the rear downtubes. No custom nothin' required.

http://fmjmotorsports.com/328is/cage/PICT1150%20(Large).JPG

Nice build....everytime I see this car....it seems to have more GOODIES....and keeps evolving....keep it up!!!

Get it done...and go play with Luke (dejablu311)....it'll be like forever for me to finish my car.....

Looking at those rear down tubes and cross bar, I am wondering what the consensus is.
My car is done the same way with the crass bar welded to plate and the down tubes welded to it. It was done a few years ago by a BMW specific shop which happens to be very, very involved in BMWCCA club racing and was built as a cage intended for Prepared class.
However, reading the rules it seems to me that this is not legal in CCA.
I am in the process of extending the cage including tying in the subframe, diff., etc. and this would be the time to change it if I had to...
So, is the rear set up in this thread legal in NASA and CCA Mod?
If not, could the O.P., and I, replace the downtubes extending them to the trunk floor, welding the side to the towers, and have the cross bar welded in between?

.So, is the rear set up in this thread legal in NASA and CCA Mod?

Not based on my own reading of the rules, but I'd recommend that you ask for a clarification before going and making changes.

Your suggestiong for a "fix" would work if you're running Mod. If Prepared, it adds two more attachment points.

Looking at the structure of the rear of my cage more closely and thoroughly, I'd rather do something different, based upon what is already existing in my car.
I have yet to apply for my license, and I'm not sure about the O.P. for this thread, but I think a clarification would be in order if someone wanted to do it...
Any interest?:)
I think there should be some people that would benefit from this, since I know there are other cars out there with rear cage structure like this...in BMWCCA clubracing.

What type of welder do you use for the roll cage and seam welding? Thanks!

What type of welder do you use for the roll cage and seam welding? Thanks!

A MIG welder. Judging by the beanie the welder is wearing I'm going to guess a Miller machine was used for this cage. :D

Carlos.

I imagine the idea behind the rule is to prevent someone with limited knowlege from welding a tube directly to the body of the vehicle without spreading the load out with the use of a plate and thinking it safe. The down tubes and X tubes are mainly to prevent the main hoop from folding or rotating on impact and having them terminate close to where the cross tube is good but having them termintate at a single node is better.

But I am not an official...