Why not a carbon fiber body?

[rlboyles]

It would seem a carbon fiber body would be a perfect fit for a Cobra, but from searching, it seems like a rare thing? Why?

[fordracing65]

Fiberglass is cheaper and with business its all about the bottom line profit, plus with these cars being so light as it is fiberglass works fine, easy to repair and alot of shops do it, there are some carbon shells but the costs really is'nt that justifiable when glass is so much cheaper.

[strictlypersonl]

The Cobra body shape doesn't lend itself to exotic materials. There are too many compound curves. In order to fully take advantage of graphite's stiffness, you really need matched dies or vacuum-bagging, neither of which is practical with a one-piece (wrap-around) body. Graphite's great on easier shapes where you can use a low resin-to-reinforcement ratio, but more complex shapes are very difficult. Not to mention, figure roughly $40/lb for materials when properly laid up with epoxy.

The bottom line is you don't gain much except for the status.

[gsharapa]

Actually carbon fiber works better than fiberglass when it comes to the curves and fender wheel wells etc. My car is carbon fiber and the lips on the fenders are rolled just like aluminum and very difficult to tell the difference. Hard to do that with fiberglass...The only thing about carbon fiber is under high fluorescent lights you can see the carbon fiber imprint like expensive race cars, but I actually like that.

[dallas_]

G-Pete has a carbon fiber body also. I expect they will become more common as time goes on. The ones I've seen are amazing.

[LMH]

I don't really know much about the process of making a carbon fiber body or working with it. Could a CF body be made in a mold used for fiberglass?
Larry

[G-Pete]

Originally Posted by LMH

I don't really know much about the process of making a carbon fiber body or working with it. Could a CF body be made in a mold used for fiberglass?
Larry

Yes, it does not matter which mold you use.

CF is expensive and the technique to do it right is complicated (compare to fiberglass).
The result are strong thin lightweight bodies. Whenever you drill holes or cut CF you need to wear a class III respirator these dust particles a pretty toxic.

If you like the looks of CF you can sand the surface and just apply clear coat.

[Bartruff1]

cost.....benefit

[rlboyles]

G-Pete the carbon fiber body on your car looks sweet. I probably missed it, but looking at your build pages I didn't see where you got your 289 FIA body? Make it yourself, had some dude make it, or bought it from a company?

Seems like the big thing is light weight. As always a lot of different numbers get tossed out. G-Pete did you weigh your 289 FIA body?

As a comparison, I saw an article from what appeared to be the man who runs ERA, and he put up a number of 300# for his body. That would seem a good touchstone for the potential weight savings.

[dallas_]

I think I remember hearing Gary and Pete say their bodies are less than 50 lbs.
If so, that's a significant weight savings.

[Three Peaks]

I have one of Roger Bollick's (Exact Cobras) Carbon fiber bodies and it is a thing of beauty. And the weight is well below 50 lbs. and very stiff.

Bob

[Dominik]

I was told that the weight savings from 'glass to Carbon Fibre is not that drastic in a wet lay-up, unless you use an autoclave - which is impractical for a complete body.

The CSX4000 main piece weighs 30kg in fibreglass. Add boot lid, spare tire insert, doors, hood, main tub (where you sit) with aluminium firewall and tunnel and you are at 70 to 75kg.

The tubular door/boot/hood frames are excluded. Give or take 5kg to be added to the 95kg of the chassis.

Total: 170kg for body and chassis.

[G-Pete]

The body, trunk, doors and hood all together 39 pounds.

The body was made by Brian Bumgarner of Missouri (816-309-1930) - in the picture below you see his car. He will just clear coat the car to show the CF finish. We plan to have the cars done by end of May...

[twobjshelbys]

My (former) Shelby Cobra CSX4005LA was a carbon fiber car. I think 6 were made (maybe 7) by HST. Two of the LA cars were CF.

[double ugly]

the Exact body weighs 46 lbs.