C3 frame flex!

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Nov 3, 2017 | 10:40 PM

#21

ignatz

Safety Car

Joined: May 2004

Posts: 4,364

Likes: 1,588

From: los altos hills california

Quote:

Originally Posted by v2racing

The Green Mamba and your car are coupes. The body in the video shows how little rigidity the body adds on the C3. Imagine how little the body helps with a convertible like I have.

I'm doing what I can to stiffen it up.

Mike

You have a real challenge. Buddy of mine put in a full roll cage after his rear frame kickup structure failed. His is a 68 and I note the Green Mamba is of that vintage. I didn't watch the whole video but looking quickly I didn't see the bare frame so I can't tell if he added the frame gussets at the rear. That would help.

Nov 4, 2017 | 01:04 AM

#22

doorgunner

2026 Loser of the Year

Joined: Sep 2013

Posts: 36,597

Likes: 7,046

From: New Or-leens Loo-z-anna

Well....that explains why Corvettes allow for the wide door gaps! No wonder the passenger door pillar on my basket case convertible has a vertical 12" crack. May as well beef up the frame before I "re-gap" the doors since I already replace all the body and frame mounts which corrected the sticking-closed door problems.

Nov 4, 2017 | 01:34 AM

#23

ignatz

Safety Car

Joined: May 2004

Posts: 4,364

Likes: 1,588

From: los altos hills california

Quote:

Originally Posted by doorgunner

I would definitely check the welds back there. I imagine torque acting on that member would flex the body at the #4 mount. Obviously that is just a guess. Have a look at the difference between the 68 and 69 and up structure.

Nov 4, 2017 | 03:31 AM

#24

v2racing

Thread Starter

Melting Slicks

Joined: Mar 2008

Posts: 2,666

Likes: 289

From: Spring Park MN

Quote:

Originally Posted by ignatz

I welded the frame solid and did a lot of gusseting. I don't really want a roll cage, it is a street car. We'll see how it does when I finally get it on the street.

Mike

Nov 4, 2017 | 04:10 PM

#25

jd1a

Instructor

Joined: May 2004

Posts: 209

Likes: 6

From: Glendale AZ

The Chevrolet Power book has their suggestions on where to weld brackets to the frame helping with flex.

Nov 4, 2017 | 08:19 PM

#26

Big2Bird

Le Mans Master

Joined: Dec 2006

Posts: 8,837

Likes: 1,028

Quote:

Originally Posted by jd1a

The Chevrolet Power book has their suggestions on where to weld brackets to the frame helping with flex.

Yup.
I also imagine that green car has a bunch of ponies and hooks up rather well.

Nov 5, 2017 | 09:37 AM

#27

3JsVette

Race Director

Joined: Jan 2007

Posts: 14,948

Likes: 3,351

From: NYC NY

That's obviously a very high end no expense spared build by some very competent builders. I'm surprised there weren't some "custom" enhancements to address the possibilities of frame flex with all the horsepower and grip the car is capable of. Maybe the resulting performance exceeded expectations.

Nov 5, 2017 | 12:58 PM

#28

v2racing

Thread Starter

Melting Slicks

Joined: Mar 2008

Posts: 2,666

Likes: 289

From: Spring Park MN

Quote:

Originally Posted by 3JsVette

Not to say this is the case with this car, because I have no idea, but I have seen very high dollar builds in both cars and motorcycles that skipped the basics. I consider welding and gusseting the frame a basic with high horsepower, high end suspension and big sticky tires. If I had the budget that went into this car, I would have looked at a stiffer aftermarket frame or at least filling the stock frame with structural foam after it was welded and gusseted. Of course I would have put a cage in the car for it's intended use.

Mike

Last edited by v2racing; Nov 5, 2017 at 12:58 PM.