Polyurethane And Carbon Fiber
 

Just some questions on the 2.
Which one is lighter CF or PU?
Which one is better CF or PU?
Has anyone ever heard of SPU? Super Polyurethane?
Has anyone made a Polyurethane kit for the RX-8 thats worth purchasing? (IE: fitment issues) This is the only one I found http://www.tspracing.com/rx804bk.html
I was going to get a Carbon Fiber hood but it feels just as heavy as the stock hood? You guys know why? I mean I dont want to pay $750 for a hood that weighs just as much as stock.
Thanks for the info.

AFAIK, carbon fiber is a superior material in so far as it weighs very little for the strength it provides. It also has some nice heat-blocking capabilities. But, as with most materials, I think it depends on what the application is. For a kit, I'd rather have carbon. It seems far more rigid than poly (which is why the sagging issues crop up). However, poly seems to be easier to work with and cheaper. But, apparently, good fiberglass is a better compromise as it is rigid and easy to work with.

From all accounts I've heard, a carbon hood should weight roughly the same as a stock RX-8 hood. This is because our hood is made of aluminum. If, for example, you go open the hood on a Civic, you'll see that it weighs quite a bit more than an RX-8 hood (something I took for granted). For some of these other cars, a CF hood might be a decent investment, but not really for the '8. As I mentioned before, carbon fiber is really good at blocking heat. Aluminum is good at transferring heat. So, if you do get a carbon hood, you might want to get one with vents. Rotary engines already run really hot. While I haven't heard anyone doing any damage with a non-vented CF hood, you can never be too careful.

Thanks I appreciate the info.

which is lighter...polyurethane, carbon fiber, or carbon fiber stickers?

Mu....
 

I'm afraid Mugatu is right. (There, I said it.)

A real CF hood would be WAY lighter than stock, but I doubt you will ever see one. The stuff they call CF is actually "HeavyAss" brand fibreglass, with a top coat of the cheapest CF you will ever see, then another coat of thick shiny gel to protect it.

Real CF would weigh about the same as that gelcoat!!

S