Trans Am E-body roll cage pics?

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Unless you're going for a spot on reproduction of the comp cars, I don't know that I'd want to copy the TA cages exactly. Even post 1970, the kit car program identified alterations that were improvements and a fair amount has been learned since then about about chassis rigidty and improvements. Looking at some of the pictures Barry put up, these cages appear to be pretty limited by the rule set of the day.

One of the biggest highlights in the ensuing years has been discovering the amount flex in the front third of the car and the need to have more rigidity in the firewall/A piller area and rocker area.

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If I'm correct, I've read that the AAR/T/A were the first TransAm cars to have ever had their roll-cages designed using a computer.

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Just a heads up, SCCA rules state 1.75" .120 wall IIRC.

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Took a screen shot off my phone.
This is the SCCA GCR as of Feb. 2014
Over 2699 lbs. 1.75 x 0.095
Hopefully I don't have to use 0.120 wall as it would add more weight

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I was wondering how the cage is going to be tied to the front shock and wanted to get more ideas. I have a heater core in the way though. I saw that Dart Lite's cage and thought it was really cool, just wasn't sure if that shock bracing went through to the rest of the cage or if it just stops at the starfish looking portion of the firewall.

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You guys make a great point, 0.120 it is
I wonder how much more it will weigh?

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it should strengthen things up quite a bit

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I like it

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Did you mean something like this?
One negative thing is that it would add a bunch of front end weight and that is what I am definitely trying to avoid

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What amount of stiffening would an engine plate provide? If any?

Engine plate

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If you run it with rubber bushings...No stiffening at all.

You can make it a stressed member if you integrate it into to the cage and frame. Needs to be basically locked and pinned in place. IMHO, not just typically bolted in place. Both holes need to ride tightly on the shoulder of the through bolt and fits so tight it needs to be tapped in.

And the thickness of the Magnum Force place is too thin for a stressed member.

Here's one we build that was fairly stout. We were in mild accidents and it bent the plate. That was sort of a downfall of the plate.



IMHO, this is a little thin on the chassis tab. but there is a lateral support gusset that you can't see.

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IMHO, if you run a tube cage I don't think you need to run the inner fender braces.

Here's a rough sketch idea of mine. Trying to route triangulation into the front chassis box. Trying to resist twist.

I don't think you could run a straight cross bar from the front k-member bolt area to the other side. I'm pretty sure that goes right through the crank pulley.

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That's a pretty comprehensive design IMO. Three areas I would like to see tweaked, if possible. 1. the short front upper 8"? connector, reduced to close to zero. 2. The L and R front upper down legs make a 45Deg? angle down towards the front, just make a straight tube starting the down angle at the last node, 3. At this same node add an angled tube heading back to lower chassis/firewall area.

Not sure but does any of this tubimg need to meet and dia or thickness requirements since not part of the cage?

Not sure how without any bolted connections, motor could be removed from above. But the design looks solid.

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IMHO, if you run a tube cage I don't think you need to run the inner fender braces.

Here's a rough sketch idea of mine. Trying to route triangulation into the front chassis box. Trying to resist twist.

I don't think you could run a straight cross bar from the front k-member bolt area to the other side. I'm pretty sure that goes right through the crank pulley.

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That's a pretty comprehensive design IMO. Three areas I would like to see tweaked, if possible. 1. the short front upper 8"? connector, reduced to close to zero. 2. The L and R front upper down legs make a 45Deg? angle down towards the front, just make a straight tube starting the down angle at the last node, 3. At this same node add an angled tube heading back to lower chassis/firewall area.

...snip...

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IMHO, if you run a tube cage I don't think you need to run the inner fender braces.

Here's a rough sketch idea of mine. Trying to route triangulation into the front chassis box. Trying to resist twist.

I don't think you could run a straight cross bar from the front k-member bolt area to the other side. I'm pretty sure that goes right through the crank pulley.

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Not sure but does any of this tubimg need to meet and dia or thickness requirements since not part of the cage?

Not sure how without any bolted connections, motor could be removed from above. But the design looks solid.

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IMHO, if you run a tube cage I don't think you need to run the inner fender braces.

Here's a rough sketch idea of mine. Trying to route triangulation into the front chassis box. Trying to resist twist.

I don't think you could run a straight cross bar from the front k-member bolt area to the other side. I'm pretty sure that goes right through the crank pulley.

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Not sure but does any of this tubimg need to meet and dia or thickness requirements since not part of the cage?

Not sure how without any bolted connections, motor could be removed from above. But the design looks solid.

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Engine crossbars generally don't have thickness specs. They are not really a safety deal, mostly performance deal.

In the pictures I posted here of the motor plate, that is initial assymbly at the beginning of the season. There are a system of crossbars yet to be bolted on. If you look closely there are small tubes going through the large roll cage tubes. Crossbars (we called it a spider web) bolts to those through tubes.

Yes the crossbars bolt on. And most connections are not bolted with a thru bolt connecting overlapping flanges.

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Here's what it looks like with the center cage bolted in.

We went to smaller grade 8 bolts becasue of weight and that the previous years 3/4" grade 8 bolts were overkill compared the bars they connected too.

The two very narrow bars are just to support the radiator.



This was a one-off all-out chassis built to win another track championship (it did) and run for national championship (close but not). Things got wacky on this car. For instance, the little welded in tubes that the cross bar bolts go thru the roll bar are machined thin in the center to reduce weight.