BrianCunningham

Doesn't anyone have, or know where I can get CAD files for the C4 Corvette's frame and suspension?

I found lot of the C4's frame dimensions in the FSM

I really want to input the whole suspension into a computer.

I'm going to coil overs and this would really help pick out the rate.

Also I'm thinking of making some modifications.
C4's are camber challenged, but just laying the upper a-arms against the frame doesn't do it. I've tried that, and it compromises braking too much.

If anyone has there car apart in the garage, can you measure the easy stuff?
A-arms dogbones etc.
I can then start work on the CAD file.
I'll provide the CAD file to anyone who helps me out.

BTW I really hope the upper a-arms in the front aren't pointing DOWN while at rest.
That would explain a lot!

black88z51

Good Luck, I tried asking for ACAD files b/f on this forum and nobody replied. Now whenever I need a 3D model for anyone of my cars I just measure and draw it myself.

Eike

I have most parts of the suspension laying around. What measurements do you need?

BrianCunningham

The end goal is to put the geometry into a suspension analyzer.

Something like this:

http://www.mitchellsoftware.com/prod01.htm



I have SolidWorks, and that may handle what I need to do.

What I need measured is geometries that are critical to how it moves.
ie) center to center distances, but not thicknesses.

If it would help I can make drawings showing what I need.

Items like the dogbone bushing center-to-center lengths should be easy to measure.

On the a-arms for instance, I need the center of the bushing hole to the center of where the ball joint pivot moves, which will be hard to measure. I need to know where the rollbar is connected, where the spring hits, where the shock is connected. These will tell me what spring rates to get.

This is no small task, but when it's done, I'm hoping to come up with some simple solutions to some of the handling issues we have.

BrianCunningham

This picture is a BIG help.



Combine it with this one


And a lot of the rear suspension behavior can be done.

BrianCunningham

Update:
I want to get the compete stock geometry down before modifying it.

That way I can measure the stock ones and see how good my model is.

69427,
WOW, I thought you bought one of the conversion frames that are available.

Aardwolf,

The 1st thing I want to do is fix that front geometry.
The top a-arm should point up, not down at rest. So either the balljoint needs to go up or the frame side needs to go down, or both.

The second thing I want to fix is that rear geometry. The dogbones are way too short!
I don't know how many here realize it, but GM actually ripped off Dick Guldstrand's rear suspension design for the C3 when they built the C4. The trouble is the bean counters got a hold of it and messed it up in the process! Take a look at the dogbones, they run all the way to the back of the upright, thus making them at least twice as long. Also instead of a toelink, he has two beafy locating members spaced equally apart and on the same plane.



I might acually just buy his upright and adapt them to the C4.
Not only would I get the better geometry, but I'd get the beefier drivetrain, and cheaper bearings.

BTW does anyone have the front pic to go with this one?

I used to have it but now I can't find it

BrianCunningham

1st crack at the C4's frame.

This doen't need to be the that accurate, so long as the suspension pick-up points are. It's more for reference.

GM's


Mine