The fc3s.org NA CF hood was about 19 lbs +/- 1 lb. It was a full replacement hood made with 282 aircraft carbon (5.7oz) with epoxy and 3M urethane bonding agent. I am not sure if anybody is still producing that hood now that fc3s.org is out of business. You can get cheapie racing CF hood skins that are about 7 lbs, but they are not of the quality that most people would want on a street car.

 

actually i think its about the same.
but i only look at 24hr memberships which is probably the most expensive.

 

The most commonly used Kevlar 49 is actually mildly cheaper than carbon.
While its slightly stronger than carbon, its not near as stiff. It is also weak in compressive strength, especially when the wet leyup method is used. It is tougher than carbon as well. Since the hood is not a part loaded by the chassis, its lacking stiffness would be of zero consequence.
The big differences are that its lighter, doesn't explode apart when it reaches its compressive yield, and it is considerable quieter than carbon panels.

 

Get the best of both worlds and use a carbon/kevlar weave. You get the stiffness of the carbon with the toughness of a kevlar.
You can even get the kevlar in different colors to it looks cool.

 

Why make a part stiffer and heavier if the application doesn't warrant it?

 

Because I would argue that stiffness is just as important for a hood as toughness.
My point of view is as a racer, more specifically an autocrosser. I've seen two common problems when using composite hoods. First is the driver forgets to put the hood pins back in after checking something, goes out on a run and the hood flies open and folds backwards across the top of the windshield. Second is they prop the hood open between runs to let the engine cool down and a strong wind catches it and folds it like a taco.
And the way I see it there are a couple of possible outcomes depending on how the hood was built. If it's full carbon chances are the hood would break in half. So not only would you have to make a new hood, you also wouldn't be allowed to complete the rest of your runs.
If the hood was built with kevlar or fiberglass (similar toughness, but heavier), then you would still have to make a new hood, but chances are it's still in one piece. So you unfold it, put the hood pins back in and make your runs.
So with that in mind, I would probably build it like this:

----- carbon -----
----- kevlar or fiberglass -----
----- foam core -----
----- kevlar or fiberglass -----
----- carbon -----

I don't think a full kevlar hood would be stiff enough, and a full carbon hood would be too brittle.
Also, kevlar is not just a little cheaper than carbon, it's about half the cost.
It's likely that the ViS hood is actually full fiberglass with just a single carbon layer on the outer skin.

 

Before reading further, I reported your post. However, when looking at the report, mods should look at your post in context, and realize that it wasn't intended to be spam and was made with the best of intentions (and was almost correct.) Thanks for digging that up!
Linky no worky for me.... any idea why?

How much does the one at AndysAutoSport cost? The VIS one looks to be about $500 shipped; I'd rather get something less expensive.
Yeah, while it's not a very sensible upgrade from an aluminum hood, if you've got a steel hood and are going to spend the money for an aluminum plus the hundred-plus dollars to ship it, may as well spring for a bit more and go CF. Plus, that way you needn't really worry about painting like you would with an already-painted aluminum hood.

 

Why? The hood is not a structural agent, what does it matter if it bends slightly while the chassis flexes? You should care about your chassis stiffness, and the stressed skins attached to it, but the hood and fenders are not stressed skins.
Kevlar is at least as stiff as aluminum when laminated to be 75% of its weight... your reasoning means that the stock hood deflects too much for your satisfaction.

 

Are you trying to sell me some kevlar?
The point is, we found one company that makes a composite NA hood. If you don't like that one you are free to make your own with as much kevlar as your heart desires.

 

Exactly. Spend a weekend or two and make your own hood.

It's not that difficult if you have some knowlege of how to work fibers/resin/composites. A first timer could probably do it.

I could do it and i've been dicking around with fiberglass for about a month now and i'm getting good results with bondo mat, short strand and jelly. No pure liquid resin. Off the shelf vatozone mediocre at best materials......

Now for a hood i'd use liquid resin and long hair WITH mat reinforcement but do the top skin in carbon fiber.


www.fiberglassforums.com

All you'd ever need to diy **** if people dont make what you like.

The downside is it is an aquired skill, requires patience and ALOT of trial and error. I've been getting lucky in my endeavors.


All said and done unless you REALLY enjoy making one off stuff you should just pony up the cash for what's already out there.

 

This whole thread was about getting a lighter hood. I pointed out that for the same price as carbon, you could make a lighter piece using kevlar.
You piped up about using carbon for its stiffness.
I countered with the fact that a hood does not need to be built to be stiff since it is not a component stressed by the chassis.
You said you thought stiffness is a hood was important, never explained why you thought so, and then rambled about "racers" too stupid to set their pins, and hood skins stupidly installed on prop rods...
I'm providing facts, not selling anything.

Been there, done that.

 

Actually Kevlar is quite a bit cheaper than Carbon, at least from where we've been buying it lately.
www.solarcomposites.com

 

Your website shows it being roughly 25% cheaper when you account for equal mass. My source (local) is cheaper for carbon, and roughly the same for kevlar.
If you were getting a hood built by someone though, I wouldn't expect any price difference between the two, simply because the products are so labour intensive, and the difficulties in cutting and properly wetting kevlar would offset any cost savings on the material.