Question to all ye Hot Rodders and racers...

1)Where does the C3 chassis take most of its strain?
Secondary areas?

2)What is the best way to strengthen it or lessen the strain on it
a)Welding
b)Suspension mods

3)How to best accomplish the above?

4)Price of mods ratio to effect of those mods

Thanks!!

 

1:
front suspension mounts, check for cracks along the channels and the welded brackets at the rear of the crossmember.
the area where the frame kciks out after the front wheels, especially where that big hole for the power steering ram mounting bracket stud plates (geez what a word) is.
rear kickup area, gm addressed some of that with the extra bracing on 69+ frames.

2: welding, gusseting, checking factory welds (the horror!) and doing a better job than the factory did.
3: buy a welder and practice till you can make strong, good penetrating and good looking (spatter free and non porous) welds. It takes practice, and get a mig machine that uses gas, not flux core. OR buy a case of beer for a buddy that knows how to weld and want to weld your stuff (this isn't done within 1 day!)
Steel is pretty cheap (well..it's gotten more expensive, dobule almost...damn chinese) the welder is not cheap though knowledge...well this board is free. Do a search on frame strengthening & gussetting., there are some interesting threads out there.

 

Get an old copy of the Chevy Power Manual 4th edition. It has a section in it on Corvette chassis prep for IMSA GT or SCCA T/A racing. It has a lot of details on this subject

-Mark.

 

I agree with TT on the first part of his reply. I will caution anyone contemplating the welding and gusseting called for in the Chevy Power book to make shure the frame is properly straightened and supported properly before welding any additional gussets or roll cages to their Vette frame (you will warp and destroy your chassis quickly if you try doing this while it is sitting on the tires.) You can talk to any expirienced welder, metal distorts and moves as you are welding long sections of any component, the Chevy Power manual calls for completely welding all seams on the frame, I wouldn't do it unless it is tied down on a frame machine of chassis table like "real" race shops have. I would not weld a roll cage into a Vette unless it was tied down as you can easily destory the frame alignment doing this procedure. The best frame guy I know bought a N.O.S. chassis and made his dedicated frame machine from this and a full scale G.M. blueprint of a stock Corvette fame (his name is Bill Grace and most of the fast west coast racers use him to get their cars in competition trim before going vintage racing.)

 

Great info guys!

Thanks

 

I'm doing a frame off and just had my frame welded in several places. (Couldn't believe how bad the factory welding was.) Didn't use a frame jig, but didn't weld long sections. Hopefully, it didn't warp because it's at the powder coater now. I had a lot of cracks in the the mentioned areas. So I would definitely recommend having the frame welded anywhere you think it is weak (about everywhere). I plan on doing some cross bracing between the front spring towers and to triangulate the rear areas under the seats.

 

The trick is to only weld short sections, the factory used skip welds and on the later frames the skips are very small and easily to weld without a chance of warpage if you alternate where you weld. The earlier frames are a bit worse, the skips are much larger there. I didn't use a jig but I did measure the frame beforehand to check for straightness and afterwards nothing had changed at all so it will be just fine.