When a Cage is needed?

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BrazilianZ28Camaro
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When a Cage is needed?

Post by BrazilianZ28Camaro » Tue Jun 03, 2014 9:36 pm

Hello Gents

I'd like to hear your experience in regards chassis rigity and the need of a cage or not on second gen Camaro, SBC around 600 HP, more strip than street deal, 28x10 Hoosier true drag slicks at the strip, TH350, Caltracs bars and high stall converter.

Car will have welded subframe conectors and its race weight is around 3300lbs.

There's no rules obligating the use of a cage, then my concern is: will a six point roll cage do any good to ET despite the added weight?


Thanks in advance
'71 Z28 Pro-Street Camaro
Pump gas -T-ram - All motor SBC 427"
3308 lbs- leaf spring/Caltrac Car
29x10.5 Hoosiers
New best 1/8 mile ET
1.45 60' / 4.12 330' / 6.38@109mph :D

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Re: When a Cage is needed?

Post by nascarfan7 » Wed Jun 04, 2014 12:08 am

Having had many 1st thru 3rd gen Camaros, slicks + 600HP = anything you can do to tie the car together instead of twisting up like a pretzel is going to help.

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Re: When a Cage is needed?

Post by nickmckinney » Wed Jun 04, 2014 2:07 pm

600HP with 28" slicks a cage is definitely needed if it gets squirrely and goes into the wall..............Around here a car with 28" slicks and that HP would be in the 9's and for sure you have to have a cage if you want to run a second pass at most tracks

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Re: When a Cage is needed?

Post by BrazilianZ28Camaro » Wed Jun 04, 2014 9:09 pm

nascarfan7 wrote:Having had many 1st thru 3rd gen Camaros, slicks + 600HP = anything you can do to tie the car together instead of twisting up like a pretzel is going to help.

Hehe, got it!

In your experience a six point roll cage is enough ? My car have full interior less back seats, then a eight point RC would be tight around the "A" pillar.

Thanks for reply.
'71 Z28 Pro-Street Camaro
Pump gas -T-ram - All motor SBC 427"
3308 lbs- leaf spring/Caltrac Car
29x10.5 Hoosiers
New best 1/8 mile ET
1.45 60' / 4.12 330' / 6.38@109mph :D

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Re: When a Cage is needed?

Post by BrazilianZ28Camaro » Wed Jun 04, 2014 9:22 pm

nickmckinney wrote:600HP with 28" slicks a cage is definitely needed if it gets squirrely and goes into the wall..............Around here a car with 28" slicks and that HP would be in the 9's and for sure you have to have a cage if you want to run a second pass at most tracks

Overhere in Brazil we still haven't a sanctioning body like NHRA to write rules to cars that do not run on National Championships. Basically , there are one day events open to street/strip cars without rules, just basic car inspections are done.

We are aways amazed seeing the lower ET you guys do with similar combos we have here... for sure we have to learn much more about suspension setup and track prep.I believe a ten second US car would lose half a second on the quarter racing overhere due the track prep alone.

My main concern is to keep the car body straight, and hopefully launch better with a cage.

Cars like mine are very rare here and many people will call me crazy for do what I'll do, but WTH, I luv this sport. :mrgreen:


Thanks for reply
'71 Z28 Pro-Street Camaro
Pump gas -T-ram - All motor SBC 427"
3308 lbs- leaf spring/Caltrac Car
29x10.5 Hoosiers
New best 1/8 mile ET
1.45 60' / 4.12 330' / 6.38@109mph :D

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Re: When a Cage is needed?

Post by nickmckinney » Thu Jun 05, 2014 7:02 am

BrazilianZ28Camaro wrote:Overhere in Brazil we still haven't a sanctioning body like NHRA.....
Yeah but you need to also consider your personal safety. The cage if done correctly will make the car stiffer and give enough protection that its a win win at your power level.

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Re: When a Cage is needed?

Post by Matt@RFR » Thu Jun 05, 2014 12:33 pm

nickmckinney wrote:
BrazilianZ28Camaro wrote:Overhere in Brazil we still haven't a sanctioning body like NHRA.....
Yeah but you need to also consider your personal safety. The cage if done correctly will make the car stiffer and give enough protection that its a win win at your power level.
Exactly. Sacramento raceway just had a 12 second car get on its roof and slide down the K rail for a little bit. He wasn't required to have a cage but did anyway, and it probably saved him from injury. You're going to be a lot faster than that, I would put a full cage in it. Then again, I wear a Hans device in a lowly 8.50 altered.

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Re: When a Cage is needed?

Post by Greenlight » Sat Jul 19, 2014 1:23 am

I had a friend with a '69 Camaro with a 650 or so HP engine in it. He only had a 6 point roll bar in it and 14" x 32" slicks.

In a two or three year time frame, he cracked a couple of windshields and cracked the joint where the A-pillar meets the roof.

He installed an 10 point roll cage and all his problems went away.
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Re: When a Cage is needed?

Post by BrazilianZ28Camaro » Sat Jul 19, 2014 9:20 am

Greenlight wrote:I had a friend with a '69 Camaro with a 650 or so HP engine in it. He only had a 6 point roll bar in it and 14" x 32" slicks.

In a two or three year time frame, he cracked a couple of windshields and cracked the joint where the A-pillar meets the roof.

He installed an 10 point roll cage and all his problems went away.
:shock:

Was a transbrake or foot brake car?
'71 Z28 Pro-Street Camaro
Pump gas -T-ram - All motor SBC 427"
3308 lbs- leaf spring/Caltrac Car
29x10.5 Hoosiers
New best 1/8 mile ET
1.45 60' / 4.12 330' / 6.38@109mph :D

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Re: When a Cage is needed?

Post by Alan Roehrich » Sat Jul 19, 2014 9:34 am

Eight point cage, subframe connectors. Either have it built with 1-5/8" x 0.125" DOM tubing, or at the very least, buy the kit with that tubing, and get assurances that the tubing will be 0.125" minimum thickness everywhere, even on the long/stretched side of any bends. Do NOT get 1-3/4" x 0.134" ERW tubing, it is heavy, and it is larger, it takes up too much room and adds up too much weight. You would think that those two minor dimensions would mean very little. You'd be wrong. Having been convinced to build a car with 1-3/4" x 0.134" ERW, once, I will not build another one with it. Honestly, I won't build one for myself with anything other than mil-spec/aerospace quality 1-5/8" chrome moly tubing, but I would not use 1-3/4" x 0.134" ERW for a friend or customer.

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Re: When a Cage is needed?

Post by BrazilianZ28Camaro » Sat Jul 19, 2014 10:43 am

Alan Roehrich wrote:Eight point cage, subframe connectors. Either have it built with 1-5/8" x 0.125"0, or at the very least, buy the kit with that tubing, and get assurances that the tubing will be 0.125" minimum thickness everywhere, even on the long/stretched side of any bends. Do NOT get 1-3/4" x 0.134" ERW tubing, it is heavy, and it is larger, it takes up too much room and adds up too much weight. You would think that those two minor dimensions would mean very little. You'd be wrong. Having been convinced to build a car with 1-3/4" x 0.134" ERW, once, I will not build another one with it. Honestly, I won't build one for myself with anything other than mil-spec/aerospace quality 1-5/8" chrome moly tubing, but I would not use 1-3/4" x 0.134" ERW for a friend or customer.

Yes, I figured out that the eight point cage is better and very easy to add those two bars from the main loop to the floor. I'm planning to build it of 4130 1 5/8" steel tubing if those wont cost me an arm and leg.

I also planning to weld the side door bars as far to the front of the car as possible and keep then as straight as possible. I'll try to weld the rear struts from the main loop straight to the trunk with the plates above the rear frame rails. I May also add a X from the main loop to the top of the wheel tubs, making it a ten point cage :-k

Right now I'm building the subframe connectors. I'll use two 1.57" straight square bars welded to the rear frame and bolted to plates then to the front H member.

Thanks for the tips Alan.
'71 Z28 Pro-Street Camaro
Pump gas -T-ram - All motor SBC 427"
3308 lbs- leaf spring/Caltrac Car
29x10.5 Hoosiers
New best 1/8 mile ET
1.45 60' / 4.12 330' / 6.38@109mph :D

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Re: When a Cage is needed?

Post by Alan Roehrich » Sat Jul 19, 2014 10:58 am

The chrome moly tubing itself is not that much more expensive, the cost in a chrome moly cage is that it must be TIG welded in order to be done correctly.

You should consider putting an X in the door as opposed to a single bar, and avoid a swing out side bar.

The shoulder to ankle bar in the door has to be 1-5/8" tubing, but the other bar can be smaller in diameter, and so can the X you are considering in the back. I've used 1" tubing there.

On that car, I'd tie the main hoop and the front hoop together with a 1-5/8" tube running parallel to the rocker.

The last Camaro I did, I used tubing welded to the front subframe and the subframe connectors to mount the roll cage hoops to, running the hoops all the way through the floor. NHRA requires a 6" square plate welded to the floorboard in a uni-body car such as a Camaro, when welding the cage to the floorpan, but I do not like welding the cage directly to the floorpan. The tubes came off of the sides of the subframe and subframe connectors to the rocker panels, the hoops ran through the floorpan, and a tube parallel to the rockers connected the outer ends of the tubes welded to the subframe and subrame connectors. Where the hoops passed through the floorpan, I used 8" square 10 gauge plates welded to the tubes and the floorpan. The car was light enough to meet minimum class weight for any class it could run with most engine combinations, and it was stiff enough that you could place a jack under any corner and get three wheels off the floor without flexing the "chassis". It could easily withstand being launched with a 700HP big block and a transbrake without flex.

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Re: When a Cage is needed?

Post by BrazilianZ28Camaro » Sat Jul 19, 2014 11:30 am

Alan Roehrich wrote:The chrome moly tubing itself is not that much more expensive, the cost in a chrome moly cage is that it must be TIG welded in order to be done correctly.

You should consider putting an X in the door as opposed to a single bar, and avoid a swing out side bar.

The shoulder to ankle bar in the door has to be 1-5/8" tubing, but the other bar can be smaller in diameter, and so can the X you are considering in the back. I've used 1" tubing there.

On that car, I'd tie the main hoop and the front hoop together with a 1-5/8" tube running parallel to the rocker.

The last Camaro I did, I used tubing welded to the front subframe and the subframe connectors to mount the roll cage hoops to, running the hoops all the way through the floor. NHRA requires a 6" square plate welded to the floorboard in a uni-body car such as a Camaro, when welding the cage to the floorpan, but I do not like welding the cage directly to the floorpan. The tubes came off of the sides of the subframe and subframe connectors to the rocker panels, the hoops ran through the floorpan, and a tube parallel to the rockers connected the outer ends of the tubes welded to the subframe and subrame connectors. Where the hoops passed through the floorpan, I used 8" square 10 gauge plates welded to the tubes and the floorpan. The car was light enough to meet minimum class weight for any class it could run with most engine combinations, and it was stiff enough that you could place a jack under any corner and get three wheels off the floor without flexing the "chassis". It could easily withstand being launched with a 700HP big block and a transbrake without flex.

Tig weld is absolutelly necessary to chrome moly tubbing?? Will be hard to find someone that can fab roll cages tig welded overhere. #-o

I'm considering not do the front loop, just like a six point RC is, because I'd have to put holes in the dash pad to the bars go through...and that would hurt. My car have a full interior, less back seat... street strip deal.

Yes, weld the bars directly to the frame is much better,but I'd like to not cut the car too much, I may do the plates with a L shape to tie two sheetmetals togheter to increase strenght as well.

Have you a website with pics of your work?

Thanks again for the tips,much appreciated.
'71 Z28 Pro-Street Camaro
Pump gas -T-ram - All motor SBC 427"
3308 lbs- leaf spring/Caltrac Car
29x10.5 Hoosiers
New best 1/8 mile ET
1.45 60' / 4.12 330' / 6.38@109mph :D

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Re: When a Cage is needed?

Post by Alan Roehrich » Sat Jul 19, 2014 11:46 am

BrazilianZ28Camaro wrote:
Tig weld is absolutelly necessary to chrome moly tubbing?? Will be hard to find someone that can fab roll cages tig welded overhere. #-o

I'm considering not do the front loop, just like a six point RC is, because I'd have to put holes in the dash pad to the bars go through...and that would hurt. My car have a full interior, less back seat... street strip deal.

Yes, weld the bars directly to the frame is much better,but I'd like to not cut the car too much, I may do the plates with a L shape to tie two sheetmetals togheter to increase strenght as well.

Have you a website with pics of your work?

Thanks again for the tips,much appreciated.
There might be three people in the world I'd trust to MIG weld chrome moly tubing, none of them are near you. Outside of them doing it, I would not sit in a car with a MIG welded chrome moly cage. You're better off with top quality DOM mild steel tubing if you cannot TIG weld it.

If you're welding plates to the floorpan, I'd consider that to be just as much a "cut" as having the tube pass through the floorpan. You're still extensively modifying the floorpan, and you'd have to do a lot of work to return it to original.

If you take the windshield out, you can run the front hoop through the dash behind the dash pad. It will be difficult to put the cross bar in. And if you're worried about the dash, you'd not be able to put the X in the door.

To me, there is no way that a cage welded to a plate welded on a stamped sheetmetal floorpan is anywhere near as structurally sound as welding it to a piece of tubing welded to the subframe.

You decide how much structural integrity is worth to you. It's worth a lot to me, for both safety and performance.

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Re: When a Cage is needed?

Post by ZIGGY » Sat Jul 19, 2014 12:15 pm

BrazilianZ28Camaro wrote:
Greenlight wrote:I had a friend with a '69 Camaro with a 650 or so HP engine in it. He only had a 6 point roll bar in it and 14" x 32" slicks.

In a two or three year time frame, he cracked a couple of windshields and cracked the joint where the A-pillar meets the roof.

He installed an 10 point roll cage and all his problems went away.
:shock:

Was a transbrake or foot brake car?
I've seen multiple foot brake Camaros & Novas with such damage including B-pillar split. And I'm not even a drag racer (though I do provide a little sponsorship
for a successful Super Pro car). I've been involved in racing most of my life and like the other guys I urge you not to skimp on the cage. Most important to keep
the cracks out of your body. Don't think you'll never need it.

P.S. - I just read Alan Roehrich's comment about MIG'd moly and agree 100%. Seen too many break in circle track crashes.

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