My new custom BOLT IN roll bar/half cage setup

[RebekahsZ]

I think you gotta have 4 bolts on each leg and the foot plates and backing plates have to be a certain dimension. Is bolting to the strut tower strong? Absolutely. Is bolting to the inner fenders strong? Not very. Does it look good? Definitely.

[JMortensen]

There is a lot of structure around those fenders. One of the main body seams runs up the wall just a couple inches away. There are better ways to do it, but the Autopower was (is?) legal for SCCA racing and it had both feet on the fenderwells.

[SDgoods]

There is a lot of structure around those fenders. One of the main body seams runs up the wall just a couple inches away. There are better ways to do it, but the Autopower was (is?) legal for SCCA racing and it had both feet on the fenderwells.

 

I feel the same.  This is designed so much better than the autopower one, I think it should pass tech no problem

[johnc]

There are no SCCA specs for roll bars in the GCR. There are some antiquated specs in the SCCA Solo2 rule book but its not enforced. No Solo2 tech inspector has the tools or equipment to verify wall thickness.

[tyson]

Nice bar/cage!  

 

Quick question while this thread is active.  I've got a slightly similar setup in my car.  Would it be benefitial for me to toss a few stitch welds at the mounts to try and stiffen up the chassis?  Or do tight bolts do a good enough job?

[johnc]

IMHO, bolt in roll bars/cages do more damage to a chassis then a properly welded in bar/cage. You're drilling 3/8" holes completely through the car in 8 to 16 places for a roll bar - those holes will be there forever even after the bar is removed.

 

Adding a few welds the the bolted in mounting plates will make things worse because 1) you can't properly prepare the surfaces for welding without removing the bar to clean underneath, 2) bolted in bars rely on spreading the load to the material sandwiched between the mounting plates and welding will probably concentrate the load at the few welds - causing tearing.

[tyson]

IMHO, bolt in roll bars/cages do more damage to a chassis then a properly welded in bar/cage. You're drilling 3/8" holes completely through the car in 8 to 16 places for a roll bar - those holes will be there forever even after the bar is removed.

 

Adding a few welds the the bolted in mounting plates will make things worse because 1) you can't properly prepare the surfaces for welding without removing the bar to clean underneath, 2) bolted in bars rely on spreading the load to the material sandwiched between the mounting plates and welding will probably concentrate the load at the few welds - causing tearing.

 

Thanks John.

 

What I was planning on doing was unbolting it so I can get everything to bare metal, bolt it back down tight and then stitch it.  You think this would still be detrimental?

[JMortensen]

There are no SCCA specs for roll bars in the GCR. There are some antiquated specs in the SCCA Solo2 rule book but its not enforced. No Solo2 tech inspector has the tools or equipment to verify wall thickness.

The Autopower used to be a legal basis for a cage, even though the main hoop didn't go all the way to the floor. Nobody checks rollbar specs, but you will find that Boss Frog and others that make bars follow them anyway, using 1.75 x .120 on Miata bars even though it's overkill.

[johnc]

You think this would still be detrimental?

 

Most likely.  You're focusing the load on the small stich welds which can start a tear in the chassis sheet metal.  A welded in plate needs to have a larger surface area and should be welded all around to spread the load.  The plates on the bolt-in roll bars I've seen are really too small to be welded in.  You can weld a larger plate to the chassis and then weld the bolt-in roll bar plate to that.

[tyson]

Most likely.  You're focusing the load on the small stich welds which can start a tear in the chassis sheet metal.  A welded in plate needs to have a larger surface area and should be welded all around to spread the load.  The plates on the bolt-in roll bars I've seen are really too small to be welded in.  You can weld a larger plate to the chassis and then weld the bolt-in roll bar plate to that.

 

Thanks!

 

You just saved me a couple hours of what would have been probably worthless work.

[Ryan Merrill]

Does it affect leg room? The only issure I see is that some of use are running coilover and camber plates on the rear

[SDgoods]

Does it affect leg room? The only issure I see is that some of use are running coilover and camber plates on the rear

 

I had my seat mounted in first and I knew it fit with the autopower bar, so  knew this would fit utilizing the front holes on the fender well.   It could be an issue if you had longer legs and needed the seat further back.

 

Yes it also would get in the way of camber plated in the rear.  Im running ground control and (obviously) it can be used with them.  might be a different store for an a coiliver system from another vehicle.

[tyson]

Does it affect leg room? The only issure I see is that some of use are running coilover and camber plates on the rear

The one I have is similar in that it also attaches to the wheel arch at a very similar position.  I'm 6'4 and have some recaros installed with a very low profile slider.  The bar doesn't impact my ability to move the seat back or recline.  In fact, the back of my seat hits the wheel arch before it comes in contact with the bar.

[tyson]

The one I have is similar in that it also attaches to the wheel arch at a very similar position.  I'm 6'4 and have some recaros installed with a very low profile slider.  The bar doesn't impact my ability to move the seat back or recline.  In fact, the back of my seat hits the wheel arch before it comes in contact with the bar.

 

I'd imagine it's possible to have a plate with slots in the top to have the camber plates being used, but I'd imagine they would need longer studs to clear the stock shock mount metal and the roll bar plate.

[SDgoods]

 

The one I have is similar in that it also attaches to the wheel arch at a very similar position.  I'm 6'4 and have some recaros installed with a very low profile slider.  The bar doesn't impact my ability to move the seat back or recline.  In fact, the back of my seat hits the wheel arch before it comes in contact with the bar.

 

I'd imagine it's possible to have a plate with slots in the top to have the camber plates being used, but I'd imagine they would need longer studs to clear the stock shock mount metal and the roll bar plate.

 

 

It would be a tricky and unique setup to that car, but it could probably be done, and would certainly look badass.