I started a thread similar to this on a Corvette forum, about C4 Corvettes...because I had little luck finding technical information on that car's frame. The thread turned into a windfall of information, so I thought I might try the same thing here.

Likewise, there is the ongoing argument regarding the effectiveness of various frame stiffening products. But as some people have commented, there is no objective data to prove that these parts actually do anything meaningful. The first place to start is w/the original specifications for the frame. Torsional stiffness, bending, etc. IS this type of data out there? Can we post it up here? How about drawings of the frame?

In the Corvette frame thread, I learned that the C4 has a torsional stiffness of ~2500 lbs/degree. Benchmark sedans (CTS, Audi, etc) ahve torsional stiffness roughly 10 times greater than that, and the C5/C6 are around 4x stiffer at ~10,000 lbs/degree. So the C4 isn't very good. Where does the f body rate? I thing that it's better than a C4, but no data. What data exists for this platform? Post up!

 

C4 would have to be pretty bad to be worse than a stock f-bod!
I do know that in addition to flex through the passenger area,
the front stucture of a stock third will "matchbox"to a visable
degree-i was shocked when i first noticed the phenomenon on
mine years ago...
sfcs,welding certain seams,adding gussets here and there,stbs,
extra x-members, etc. eliminated most of the flex.
I do know when GM designed these cars,models of the body
were made of a plastic that showed stress areas...

 

Crush a empty beer can and that will give you and idea of how strong a f-body is.

 

That is funny!!!!!!!!

I laughed out loud. mtter of fact, I am still laughing.

 

Tom, they are heavy flimsy cars, period. What has kept the weight down so to speak is the unibody contruction, but with years of chassis metal fatigue, they are worse for wear unless aftermarket braced everywhere with all the specific braces already listed. Once this is done, they are proven performers- strip the interior, fiberglass hood, aluminum motor, SFC's and various other braces and a full cage and your are done. You have a car rivaling exotics.

 

Looking for technical data here. I know all about the subjective nature of 3rd gens unibody; I owned and "built" three of them. Now I'm interested in objective data on the structure.

FYI, you do know that the C4 is also a "unibody" and therefore subject to the same issues that you cite for the F body?

 

I happen to be a Vette guru.

The data you seek, I do not know. Not to sound like an ***, but I personally do not care even at the level of knowledge I have. Simply put, if it flexes, then brace it. Simply try and keep those tire footprints flat and large. take pyro reading, if womething is lacking, fix it.

I just don't get the book smart engineering. I am hands on.
I think info like this is pointless so I will not post anymore so i do not offend anyone.

But I know nothing. I only boasted the best handling 3rd gen camaro ever on street tires and have documented the perfomance #'s.

 

Sounds like a great plan. I agree that you shouldn't post more, given your perspective.

Objective info is useful as it allows one to SEE the improvements. If we know the stock chassis data, then we can measure the post modification data, and see how it compares. Then we actually KNOW something, rather than guessing.

 

That is interesting. Can you post a link to that? Or was that in print somewhere?

 

There is a pic of that,IIRC,in Michael Lamms book
"camaro,the third generation" i cannot remember if
the plastic model was full scale or not,but i was pretty
large.