CF vs FG - what are the disadvantages of FiberGlass?
 

Hello,

I am thinking of getting a vented hood to help cooling (not that there is anything wrong) and I was wondering what to choose cheaper Fiberglass or Carbon Fiber.

I would like to know whether it is one these "you get what you paid for" with FiberGlass as it seems to be really inexpensive compared to CF.

Thanks,

Sorry for my laziness if there are plenty of threads on it already...

Depends what you plan to do with the car. If your going to track it and weight is of value, of course you would benefit from carbon fiber. Or if your going for a show car look or not having the hood painted, it would give it that aggressive look. However, if your just using it as a daily necessity to vent heat or might paint over it to match the car, fiberglass is just fine. If anything your just getting the "look" of it from my opinion.

why don't you do a cooling mod that would make a bigger difference, like upgraded oil coolers? The stock hood is plenty light (aluminum remember?), and half the aftermarket hoods out there are flimsy pieces of shit that don't last (especially fiberglass). You may also have to deal with the bullshit of hoodpins.

If your goal is better cooling there are so many better ways to spend your money.

There's almost ZERO parts on the market that take advantage of the extra strength of carbon fiber (and thus extra weight savings). Most just have 2 products, a fiberglass one, and a fiberglass one w/ a cosmetic carbon layer.

I have already spent time and money on the water cooling system so far (Pettit AST, rad silicon hoses, Koyo rad, FC thermoswitch) and I am at the point where it 's either oil cooling system or vented hood (engine's 9000 miles). One thing though, is I don't have a garage, although I found ways to do everything myself so far, upgrading the single oil cooler on my Touring by a Mocal or Setrab for instance would a bit complicated for me and my limited garage availability issue). I will AutoX and track it with limited usage and "spirited driving" street most of the time (not my daily driver either). I thought that vented hood just for cooling efficiency would be a good idea. I realize oil cooling efficiency would be more beneficial but at one point hot air escaping cramped engine bay would be good too (ideally both I know, well eventually, don't know ratio).

And how about in terms of reliability and life duration (I don't know if one would go bad earlier, or whatever disadvantage of either of those, apart from weight saving)?

It's pretty simple, if your going to paint it ( which you should ) there is no reason to go with carbon.

How about weight comparison between stock and FB? I know CF is super light, my friends R32's CF hood is so light.

Lets say the carbon is 4 lbs lighter, do you really think it going to improve any aspect of your car? The only impact it will have is on your bank account...... Dont get me wrong, I like the carbon fiber look, but especially in a street car is possesses no befits whatsoever. BTW Loyoto Machida ftmfw.

Do you know the weight advantage of FB vs stock hood by any chance?

From what I remember the FB and CF hoods for the most part are heavier than stock, unless you go dry carbon you won't see much, if any weight advantage for the FD hood.

99% of the Carbon Fiber hoods out there are "wet carbon." So underneath it is a layer of fiberglass. So if your going to paint it get the Fiberglass hood and save yourself some money.

If I were you I'd install water injection.

AI systems are possibly the biggest cooling upgrade around because they keep the temperatures down at the core. Especially if you're going to the track.

I'm pretty sure that wet carbon is still all carbon fiber. Wet carbon describes a CF matrix that is filled solid with resin, giving it a wet look. Dry carbon has less resin.

Get yourself set up with a parallel oil cooler setup, its leaps and bounds more efficient than a stock (sequential) system.

Thanks for your answers everybody.

Correct.

Dry Carbon refers to Carbon infusion and Pre-Preg constructions.

Wet Carbon is all the rest.

The reason cosmetic carbon is used is $$$. Let's say a hood in CF today is 750$, well a "proper" CF Hood would easily be 1,500$ just because you are using a material that is 10 times more expensive also Epoxy resin is also much more expensive than Poly or Vinyl Esthers.

The way I see it if you plan to paint it go with FG if not go with the CF....

Not to mention autoclave time, vacuum bagging, etc. Real dry carbon is expensive for a reason.

bonnets
 

One big advantage of a fibreglass hood is should you have to , It can be repaired , Dont think cf can. Cf shatters sending splinters every where, Not good on the track.

Fiberglass will splinter too. You can repair CF in the same manner as you would a fiberglass piece.

90% of the FG hoods people bring into my shop to have painted fit like *SHIT*. Although most people seem to be perfectly happy with, and actually RECOMMEND them afterwards. Don't know why, maybe I just have high standards?

CF will *usually* fit better out of the box because the company selling it knows you're just going to bolt it on and go. A FG one has to be painted so they leave it to the body shop to fix their SHODDY work.

That's my findings anyways.

OH. And no matter what hood you buy, if its lighter then stock, I'd be amazed. If you're concerned about weight at all unbolt the stock hood and feel it. Shit weighs nothing.