Is a C4 the right platform for this project?
 

I have a project which I want to do and the more I think about it the more I think using Corvette underpinnings is the best. I mean, they are affordable, great performers and I get to save a Corvette from going to the junk yard, as I will try to find a salvage car or rolling chassis. So what's not to like?

I'm still not sure if C4 or C5 yet. I'm hearing different things. It seems the C4 would make things easier because of the clamshell hood design as well as having less computer stuff to deal with. But some say the performance and handling of the C5 is way better and night and day better. Others say the difference is not much and the C4 can be upgraded to be as good as a C5. But then others say the C5 can also be upgraded and to a level the C4 can't follow.

But to be honest, I might just go with the platform which makes the project the easiest. I'm not looking to create a race car or anything. It's to be a road car.
So am I right the C4 would make things easier? When it comes to things like this the newer the car the more complicated to get things to work because of too much computer stuff. Also, since this will be a rebody of sorts, I think the C4 with the clamshell design has a better frame to start with? The C5 is more like a normal car where it has a fender frame etc. So you need to mod that to fit the new body. The C4 could take a clamshell hood with a new shape. Or am I wrong here?

What I want to do is basically an open wheel type of sports car. I know exactly what I want. But how much of it I get will depend on the complexity to achieve it. For example, to do it exactly as I want I would probably have to stretch the wheelbase. But I'm not sure how feasible or advisable this is. I hear the C4 frame is on the softer side. But I found people using stretched C4 frames for 50's Chevy cars. I also saw people using stretched C4 frames for Batmobile replicas. Although I guess they are probably not worried about performance.

If stretched I would need the engine to stay in the same position and only move the front wheels forward. The full length of the car doesn't necessarily need to increase. It can if it has to. Or it can stay the same length if it's easier. Just the wheelbase needs to be longer. It's fine if it stays the same length with just the wheelbase longer and a shorter front overhang for example. I'm not sure how many inches I would like or need to stretch. But probably not more than 10" or so.

So is stretching something that can be done in the way I propose? How would it affect the handling and dynamics of the car? I guess it would make the car more front middle engine. So may be a good thing for the handling? If it will be bad I can try to make do with the standard frame without stretching it. But that will throw off the proportions I want.

I would like to keep the interior and everything else. So the car would be a complete car with proper sound isolation and proper finish etc. So it would be basically a rebody of sorts.

I can't think of a better platform than the mighty Vette. It crossed my mind to use a Kappa because it's newer but not as expensive as a C6. But I would want a V8 swap, so might as well go with a C4 or C5.

Thanks for your help.

I think you should go on racing junk and look around for a few months until you find what you are looking for. Why go through all this?

You can buy a project like you want or a complete race car for a few grand.

If it were me and increasing the wheel base was your main priority, I'd buy a C4, cut the mid section of the car and add frames, sub frames and a longer propeller shaft.

That seems easier to me than screwing around with moving the front suspension.

My .02.

I'm not sure I understand what you mean. But maybe you misunderstood me. I'm not building a race car when I said open wheel. It's a road car. :)

sounds like you want to build a vette-kart....

do a search...

its been done...

ALOT...

The problem with this is, the reason to make the wheelbase longer is exactly to make the front longer, so the cabin sits more towards the rear. If I understood you correctly, your way would actually make the cabin longer?

I couldn't find clear pictures of the C4 frame from the top. But I thought maybe if cutting behind the front suspension and adding a spacer there, it would be simpler and not need to fabricate new suspension mounting points etc?

Yeah, I saw those. But this is not what this is. It will definitely have a body. ;)

You'll have to post a pic, or something for frame of reference. Take a street car and change wheel base and make open wheel? I don't get it.

Something like THIS?




https://cimg1.ibsrv.net/gimg/www.cor...051d1b38e9.jpg

https://cimg1.ibsrv.net/gimg/www.cor...57e2a5e77c.jpg

https://cimg6.ibsrv.net/gimg/www.cor...ef1a54f97a.jpg

No, no. Not at all. ;)

I mentioned it would have a clamshell hood in my OP. So it can't be a naked car. :)

Sorry. Let me be more clear. The idea is not that different from 30's hot rods. They were open wheel and yet still had a body. ;)

I got you now. One diff though; 30's car bods were typically narrower than the track by quite a bit. They had fenders and running boards that protruded out beyond the body. What this means is that once you remove everything but the body, the wheels were wider than the body, giving in a sporty look. A modern car won't have those features and so I feel that it will look a bit more ungainly. IDK for sure though. Maybe you have a grand master plan.

Nothing wrong w/the C4 chassis as a building point. A C5 won't be meaningfully better other than that the frame is stiffer than the C4 frame. Here is a TON of info on the C4 frame for your reading pleasure...

FRAME TECH

You may have to click on "broken pics" to get them to open directly at photofuckit.com

That's because the fenders were not part of the body. So to extend a frame and not have to worry about the body is/was a much easier project. If you really want an open wheel C4 or C5 corvette you will have to eliminate or significantly cut most of the panels off the car. If all you want to do is extend the frame check out the Limo companies that have specifically made C4 or C5 limousines. You want frame cutting / stretching info they're the experts.

the C5 structure is stronger, bar none
These arent like older cars where you lift the body off the frame, you cant.

The older street rods used suspension components mostly not the whole C4 structure.
Think you need to check into these more to see how the body is attached to the structure before going forward not sure its what you want.
Both gens are dirt cheap just get a well maintained one. C5 engine is cake to work on, the rest of the electronics are more complicated. Both have discontinued parts.
Cheap fixer vettes can be the most expensive as majority of parts are vette specific so they "got ya" on $$

Hey thanks for that link. Great info there it seems. I need to go through it. But I already found some useful images. :)


Yes, the bodies were narrower. But I had the impression I could do the same with the C4 and leave the wheels off the body. This is the main reason I think the C4 would be easier. I think the C5 has fender holders or whatever you call them bolted to the body. The C4 being a clamshell hood doesn't.


https://cimg5.ibsrv.net/gimg/www.cor...b367539dff.jpg



At the front, see how the frame narrows down after the cockpit? I was thinking this could be the narrower body? So the wheels would be left out.

This is the advantage I see in the C4 over the C5. At the front I don't really need to cut anything off the frame. In the C5 I would have to cut the frame where the fenders bolt to. But the C4 doesn't have them. Unless I'm getting the wrong impression from looking at pictures.

I wasn't thinking the C4 was body on frame. But you can still take off all the body panels and have a basically driveable car, right?


https://cimg0.ibsrv.net/gimg/www.cor...f8818393b0.jpg
So a rebody is much easier than on some other cars. I think the C4 is even easier to rebody than the C5 for the reasons I explained above.

Yes. I did that in the thread that I linked above. Video of a "no body" C4 driving....right here:


This is what a C4 looks like with NO body, and the rear subframe (fuel tank support) removed:

https://www.corvetteforum.com/forums...2&d=1505096887


https://www.corvetteforum.com/forums...3&d=1505096887




I think both cars would be similar. The body panels are attached in very similar ways. The C4 does have a clam shell, but once opened or removed, there are still a bunch of braces and panels that are bolted to the frame, similar to how the C5^ fenders are bolted to the frame. You're un-bolting all of that either way. The rear fenders, tub, halo....all that stuff is glued to the frame on both cars. Use a heat gun and HEAT it, and the panels come off relatively easily. Don't heat it...and you'll ruin everything trying to get it off the frame.

Oh yeah, I have seen them on CL by ,e before. Te 2 I seen over the years had lt1 motors. I think I seen someone do the caterham Idea too using a c4 in wisconsin.

I'd still find a kit or someone's project if this is what you wanted.

Thanks for posting the pictures. They help a lot to understand.

By the way, I've been looking for a picture from the top to see how wide the engine is within the frame and other details. But I can't find a picture from directly above a stripped car. C4 or C5.

About the body panels I was not aware parts were glued or that the C4 also had stuff to unbolt even it being a clamshell. So I guess as you say it doesn't make much difference which one I use. Unless if I want to keep the hood a clamshell and having the clamshell system already in place in the C4 would make it way easier.