vette c4 front suspension point dimensions

Hey guys,
im looking for some dimensions on the origonal mounting points for the c4 front suspension.
i know alot of you gus are running c4 front suspensions, so i figured somebody has all the specs/measurements/angles i need to set up where i need to fab my mounts up.
i am building this from scratch out of tube moly, and i want to set this front up at stock geometry, then go from there.
thanks guys
jay
 
Most GT40 replicas only use the C4 upright, then fabricate the wishbones etc to suit the chassis as the wishbones are not mounted parallel to the car centerline, but converge toward the front in most cases. Also check the scrub radius of your C4 stuff and plan to reduce it as much as possible during your build by relocating rotors ,calipers ,inboard further if possible.
 

Charlie M

Supporter
Jay,

I started to go down this route. I want to run pin-drive BRM style wheels. The Corvette wheels have a very deep backspace (around 6.5"). If I used the Vette suspension with the wheels I want the scrub radius is bad (as J M said) and there would be very little foot room in between the LCA pivots. I decided to look for something else.

I actually bought an '86 Vette and disassembled, measured, and made CAD models of the front suspension components. If you're still interested in pursuing this, PM an email address to me and I'll put together the info you're looking for.

Charlie
 
guys , this is not for a gt40.
its for my porsche 911 project where i think i can fit all this well.
i will be using c5 z06 17x9.5" wheels but i wil check the scrub. charlie, i am sending a pm
thanks
jay
 

Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
guys , this is not for a gt40.
its for my porsche 911 project where i think i can fit all this well.
i will be using c5 z06 17x9.5" wheels but i wil check the scrub. charlie, i am sending a pm
thanks
jay

Curious as to why you chose a GT40 forum to ask your Corvette question?
 
well bigfoot.
i am using a 016 audi transaxle, and have found alot of help on here, as well as noticed alot of technical knowledge on this board.
Ive also noticed in my searches of the internet, that c4 front suspension is used on gt40's at times.
since people here may build custom frames to add c4 front suspension to, i thoguht there would be a chance someone here would have the dimensions available.

does that make sense?
 

Charlie M

Supporter
The DRB's use C4 Corvette suspension. A couple of those guys have helped me out with suspension questions. I've been to Corvette forums with questions like Jay's. I couldn't find much help there. This forum is a great resource for many car building questions.

Charlie
 
Jay - I think a kit manufacturer named Active Power uses Vette suspension components on their GT40 and M series chassis.You might check with them or peruse their website. A.J.
 
guys , this is not for a gt40.
its for my porsche 911 project where i think i can fit all this well.
i will be using c5 z06 17x9.5" wheels but i wil check the scrub. charlie, i am sending a pm
thanks
jay

I'm using complete C5 uprights & hubs, Z06 brake package and stock wheels from a C6. With that lot put together (basically a Z06 setup) the front scrub radius is ~0.5"

The corvette PCD at 5" is a PITA to get non-corvette looking wheels for and they've got somewhat unique offsets also to get the scrub radius right.

I personally think that the C5 route is going to be a better way to go in the long run, as essentially its still the current stuff.

I am NOT a Corvette expert but from what I've read though the stock suspension geometry on the C5 was horrible (to be technical). You've not got an engine getting in the way of the front suspension so why continue with the compromises that that forced on the original design?

Whatever you do have fun with it though :thumbsup:
 

Charlie M

Supporter
I've had several PM requests for the C4 front suspension dimensions so I'll post them here. I took the best measurements of the mounting points that I could with the stuff on the car so I can't guarantee the accuracy but they should be close. It was a few years ago that I did this, I may have arrived at the distance between the control arm pivots using the published track width for a 1986 Corvette. The components I removed, measured and modeled in CAD so they should be fairly accurate.

I've seen manuals used by body shops that give chassis dimensions. If anyone here has access to something like that and can confirm some of the dimensions, that would be helpful.

HTH

Charlie
 

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Terry Oxandale

Skinny Man
Thanks for the diagrams. I took stock setting and then modified it to gain a better anti-dive, while still maintaining the caster increase on compression. Keep in mind the C4 had two different uprights. The earlier one is about 1" shorter (upper portion of the upright) than the later versions. This becomes helpful if you need to change the IC for any reason (poor planning, post build changes, etc).
 

Charlie M

Supporter
Keep in mind the C4 had two different uprights. The earlier one is about 1" shorter (upper portion of the upright) than the later versions. This becomes helpful if you need to change the IC for any reason (poor planning, post build changes, etc).

The measurements I took were on an early one (1986). I bought the car as a potential donor but changed my mind and sold it.

Charlie
 
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