LS Grand Am Frame Strengthening Questions

tdvick

Master Mechanic
Jun 25, 2010
344
126
43
Elk River, Mn.
I did also use the aluminum body mounts from JT Raceshop. I haven’t driven the car yet so I don’t know how harsh they’ll be…
 
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scoti

Royal Smart Person
Sep 5, 2019
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Triangulating the rails where possible is best but just tying the frame rails together where possible is an improvement over stock.
That front set-up, connecting the link bar mounting points together, & the rear shock brace from UMI are worth adding.
Adding a brace @ the extreme rear of the rails is another opportunity that's overlooked.
 
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pagrunt

Geezer
Sep 14, 2014
9,170
15,350
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Elderton, Pa
Triangulating the rails where possible is best but just tying the frame rails together where possible is an improvement over stock.
That front set-up, connecting the link bar mounting points together, & the rear shock brace from UMI are worth adding.
Adding a brace @ the extreme rear of the rails is another opportunity that's overlooked.
Buried deep in the old threads I beleive there was one about home brewed frame braces. This included frame rail end braces.
 
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scoti

Royal Smart Person
Sep 5, 2019
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Buried deep in the old threads I beleive there was one about home brewed frame braces. This included frame rail end braces.
I recalled seeing the information in a post/thread which is why I mentioned it. Not sure what thread though....
 

Built6spdMCSS

Geezer
Jun 15, 2012
5,804
9,715
113
Florida Beach
I did also use the aluminum body mounts from JT Raceshop. I haven’t driven the car yet so I don’t know how harsh they’ll be…
My SS is all solid aluminum body mounts. Much stiffer..

20221123_164339.jpg
 
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CopperNick

Comic Book Super Hero
Supporting Member
Feb 20, 2018
3,362
3,019
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Canada
For myself I have the UMI upper shock tower brace, upper and lower Hotchkis rear axle control arms, and an aftermarket 1/4 inch square tube t-mission crossmember.

Boxing the frame with the body still attached is possible but instead of going for a butt joint where the two edges, top and side, meet directly, you may have to trim the boxing strip so that it fits snugly inside the upper and lower rail panels and then indent it to get a 1/8th to a 1/4 inch of sill that you can use as a threshold or step for your passes. Remember to chamfer the insert panel(s) to get a wider surface to throw your passes at, it gives better penetration for more strength.

Absolute best option is to swap out the stock frame for a specialty iteration specifically built for the G-Body. Couple of the sponsors on this board are builders/suppliers.



Nick
 

scoti

Royal Smart Person
Sep 5, 2019
1,979
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Texas
For myself I have the UMI upper shock tower brace, upper and lower Hotchkis rear axle control arms, and an aftermarket 1/4 inch square tube t-mission crossmember.

Boxing the frame with the body still attached is possible but instead of going for a butt joint where the two edges, top and side, meet directly, you may have to trim the boxing strip so that it fits snugly inside the upper and lower rail panels and then indent it to get a 1/8th to a 1/4 inch of sill that you can use as a threshold or step for your passes. Remember to chamfer the insert panel(s) to get a wider surface to throw your passes at, it gives better penetration for more strength.

Absolute best option is to swap out the stock frame for a specialty iteration specifically built for the G-Body. Couple of the sponsors on this board are builders/suppliers.



Nick
Best option when cost is not a factor.
 
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UC645

Royal Smart Person
Apr 20, 2020
1,083
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Kittanning, Pa
I haven’t seen anyone using something like this, however I’ve only seen a brace setup like this on Trick Chassis’ website….

Not saying to throw ton of money at it, but if time is a factor and you’re unable to separate the body from the frame, a brace setup like that might be the best compromise. Exhaust fitment will be difficult however.

You could stand to stiffen the body a little if you throw poly body bushings at your car.
ASC worked out a rear seat brace for the GNX’s that Kirban reproduces:

If you’re handy with a welder, it’s far cheaper to make your own.
 
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smed7880

Greasemonkey
Jul 27, 2010
132
171
43
Found rust in the left rear frame rail. Its body off now.

Will box while out. Not sure what else yet. Ordered the Hellwig 11104 G body kit.

Thanks for the input. its nice to ask rookie questions on a car forum and get intelligent replies.
 
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