Need advise on 69 frame enhancement

Bullshark

Well-known member
Joined
Mar 23, 2008
Messages
710
Location
St. Charles, Missouri
We are in the middle of a frame off restoration and would like to beef up the frame while it is bare. I remember some threads on the topic but cant find them. Where do we start? Help appreciated.

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Bullshark
 
Go to the downloads section, click on the Chassis and Suspension folder and look at the Chevy Power pdf file. Good info in there on beefing up the frame as well as other mods.
 
Can't help but comment that it is just sad to see the frames on all of the famous cars of the past....all brown, and lucky if they not holey......


at least we have GLASS going, :cry:
 
C3 frames suck in torsional and longitudinal stiffness. Makes me think that an X brace would help tremendously. When GM made a C4 convertible, they added an X brace to stiffen. It worked so well they added it to all cars.

It would be interesting to explore.
 
C3 frames suck in torsional and longitudinal stiffness. Makes me think that an X brace would help tremendously. When GM made a C4 convertible, they added an X brace to stiffen. It worked so well they added it to all cars.

It would be interesting to explore.

Where was this X added??


:beer:
 
The frame looks salvageable and the car is of the wanted years. Why do you want to mod it ? I realize this forum is all about modding, but other years are better for this type of thing.
Besides, unless you go to a triangluar reinforcement involving the birdcage, it won't do all that much.
My .02$
 
We will keep the body and interior pretty stock looking. The engine was in bad condition (apart gathering rust) however could be rebuilt if so inclined. (350cu, 350hp) not a high demand config. We are not NCRS purists and are not doing this thinking that this car is or could be high dollar. A good resto mod will be definitely more fun and worth just as much if not more depending on quality. And believe me Chip up at Competition Marine is all about quality. He is the guy that put my all aluminum 750hp Dart engine together for my Blue 69 vert. Besides, we like the 68-72 cars too. We will beef up the gussets and other weak areas to optimize the frame strength consistent with guidance given here. X-brace seem difficult to incorporate on these C3's. Reinforcement involving Birdcage and frame are on the table as we get are arms around final config. Plan to put efforts in high gear as soon as Chip finishes this GT350R build.

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That Mustang has me drooling.

Speaking of which, I have a 4-speed from a '66 that I need to sell. Anyone know any Mustang restorers? :smash:
 
That Mustang has me drooling.

Speaking of which, I have a 4-speed from a '66 that I need to sell. Anyone know any Mustang restorers? :smash:

MAN, did this bring back memories of a long past event.....some 30 years ago, a neighbor friend had a '65 Mustang setting under an oak tree in his back yard it sat for some 20 years or so....it was his race car....wife left him, he parked it, I did not know it was there, until the family sold it upon him passing......it was a REAL Cobra pack cat, all the shit.....engine trans interior badges.....but when the buyer got it with the tow truck, it came apart due to sunk in the ground rust......Fastback Green, ALL the markings Cobra Pack.....sold for 500 bux the silly scraps were worth 4x that alone.....dress up any 'Stang' with them and get a fortune.....serial tags are easy to swap.....


:crutches:
 
People racing with the C3 frame had a regime of gussets they would weld to the frame to strengthen it's torsonal strength. Many years ago, I had a bunch of stiff paper templates to use to cut out the steel to weld to the crossmembers...long lost. All of the crossmembers will benefit from gussets. Also, for frame strength you must add a spreader bar between the two front control towers to prevent the control towers flexing...and changing camber...during high g turns. Maybe it's my imagination, but with the spreader bars, I imagine the front of my 68 to be much more solid, even though I'm not doing high g turns!!
 
Besides a bunch of special reinforcements i welded an upper and lower section on the original side beams of the frame which increased bending strength by more than 100%.

You can see in this picture my side beams are way thicker than the original flimsy frame, they look like bridge trusses right now:

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Have a lot of detailed pics if you like 'm.
 
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bullshark have a look at the Chevy Power Service Manual Second Edition
Section 4 on Corvette Chassis Prep... thats what I did...
 
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