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Light carbon fiber hood?

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Old Dec 4, 2003 | 10:55 PM
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Light carbon fiber hood?

I'm looking for a light carbon fiber hood for a race use only car. I'd like it to be at least 5lbs lighter than the stock hood (I weighed it at 21.8lbs), vents for cooling, and decent fit quality. I will be painting the hood, so finish quality isn't of primary importance.

Any suggestions? Most of the decent quality hoods tend to be about as heavy as the stock hood. I'm willing to accept some loss in strenth/durability if that means it is light.

Thanks in advance.
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Old Dec 4, 2003 | 11:04 PM
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get on the tredmill and lose 5 lbs, or take a **** before you race. 5 lbs in the hood for a sacrifice in quality is dumb IMHO
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Old Dec 4, 2003 | 11:18 PM
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well dont forget the advantage of having vents without having to hack up your stock hood. i have been looking for the same thing but havent been able to find it. when the time comes im making my own hood.
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Old Dec 5, 2003 | 12:02 AM
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my scoot hood i made out of full cf weighted in at a heavy 10.5lbs with 1 layer of 12k12k twill reinforced with about 3 layers in certine areas, im pretty sure i can make one which weights 6.5lbs and possibly stronger but i have not tried again yet.

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Old Dec 5, 2003 | 12:28 AM
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Originally posted by XSTransAm
get on the tredmill and lose 5 lbs, or take a **** before you race. 5 lbs in the hood for a sacrifice in quality is dumb IMHO
Thanks for the advice. 5lbs here and 5lbs there done enough times makes for a light racecar. You can't really half *** it or you may as well not bother.

Perhaps I didn't make myself clear. I'm not looking for a super light POS, but I will trade some bling for weight.
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Old Dec 5, 2003 | 12:47 AM
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I've seen ultra light-weight bonnets in japan - only 2-3kg - but the price tag is truly horrific (IIRC, 5 times the cost of a standard aftermarket CF bonnet).

You'd have to be a very serious racer with a very serious wallet to justify the cost.
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Old Dec 5, 2003 | 01:23 AM
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I have a OEM style carbon fiber hood, and from just lifting upon opening the hood, it feels much ligher, at least half.
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Old Dec 5, 2003 | 01:30 AM
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the stock hood itself is damn light. But I do want a carbon fiber hood anyways. I'm thinking of getting the Mazdaspeed one myself, possibly something else depending on how I feel when I shop for one. It also depends on how much monies I have
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Old Dec 5, 2003 | 01:34 AM
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whatever you do, do not paint cf hood!!!
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Old Dec 5, 2003 | 01:36 AM
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why? It doesn't hold or what? I think it looks good not to paint a cf hood anyways.
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Old Dec 8, 2003 | 07:52 PM
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who knows the weight of the fg scoot hood ( rotaryextreme - replica ) .
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Old Dec 9, 2003 | 08:59 PM
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Originally posted by RX7SpiritR
why? It doesn't hold or what? I think it looks good not to paint a cf hood anyways.
because its a waste of time, the paint will hold but the whole point of buying cf is for the cf look, if you dont like it, buy the fiberglass version cuz its the same thing and has the same strenght.
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Old Dec 9, 2003 | 09:03 PM
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RX7SpiritR----Where in BIG BEAR?

Also you want DRY CARBON, wet carbon as in RExtreme is wet carbon which is actually sometimes a little bit heavier then just fiberglass.
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Old Dec 9, 2003 | 09:48 PM
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Originally posted by skunks
because its a waste of time, the paint will hold but the whole point of buying cf is for the cf look, if you dont like it, buy the fiberglass version cuz its the same thing and has the same strenght.
That's not true. If FG has the same strength as CF, then why does it cost more? More importantly, why do F1 race teams, even more important, aero space use CF and not just FG? I know for a fact that CF is much stronger than FG.
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Old Dec 9, 2003 | 09:52 PM
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Originally posted by RedAnotherDimension
That's not true. If FG has the same strength as CF, then why does it cost more? More importantly, why do F1 race teams, even more important, aero space use CF and not just FG? I know for a fact that CF is much stronger than FG.
see what you fail to realize is that there are different type of cf and lay ups. yes cf is a bit stronger but 99% of the hoods out there are just a thin layer of cf layed over a fiberglass/gelcoat hood. learn something before posting please
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Old Dec 9, 2003 | 10:38 PM
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What SKUNKS is posting on is WET CARBON FIBER, like I mentioned, its the same weight, sometimes more due to the extra layer.

DRY carbon is 100% carbon fiber, very very very lights and about 50-60% stronger then fiberglass
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Old Dec 9, 2003 | 10:53 PM
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For what it is being used for, carbon fiber on an RX7 is just for looks and doesn't server more of a purpose than fiberglass. Maybe if your an F1 driver going 200mph or you drive a space shuttle, it would be beneficial to spend the extra money for the tiny strength increase cause it may save your life.


Also the weight differences are so minimal on just a carbon fiber hood over a fiberglass, it's not worth twice the price. And like Skunk said, most of the hoods out there are fiberglass cores and carbon fiber overlays.


I do like the bling factor though.
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Old Dec 9, 2003 | 10:54 PM
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if it was 100% carbon it would still be flexible cloth.

the difference between what you call dry (and is actually called prepreg) and wet layup carbon is just the percentage of resin in the finished part. a prepreg part can be as low as 30% resin while a wet layup might be 50%. less resin yields a stronger lighter part, however even wet layup carbon is stronger than fiberglass by a good margin.
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Old Dec 9, 2003 | 11:17 PM
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But is the extra strength needed on a FD? No



On a space shuttle or F1 car? Yes
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Old Dec 9, 2003 | 11:24 PM
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Originally posted by rockshox
if it was 100% carbon it would still be flexible cloth.

the difference between what you call dry (and is actually called prepreg) and wet layup carbon is just the percentage of resin in the finished part. a prepreg part can be as low as 30% resin while a wet layup might be 50%. less resin yields a stronger lighter part, however even wet layup carbon is stronger than fiberglass by a good margin.

YA YA YA, you know what I meant.

Wet lay^up would be stronger and heavier too, the point is to get it lighter, not heavier.

A hood isnt going to save your life. its all about looks which dry carbon looks kind of shitty, and wet looks better, dry would be good if your racing and trying to lighten up your car
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Old Dec 11, 2003 | 01:26 AM
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So does any one make a dry carbon hood? Like I said, I'm looking for a little (yes I know is will only be a little) weight savings and appearance is not important.

Or are any hoods that are not too much $$$ all aimed at the volume market which seems to want the look, not so much the weight savings?

Thanks for all the responses!
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Old Dec 11, 2003 | 05:25 AM
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RE-Amemiya is all I know about.
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Old Dec 11, 2003 | 01:45 PM
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RE Amemiya does not make dry carbon hood.

The only dry carbon and autoclaved hood made is by Mazdaspeed. The R Spec hood is about $3350 with shipping from Japan

Who wants one? I can import it for you.

Originally posted by SpiritR
RE-Amemiya is all I know about.
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Old Dec 11, 2003 | 01:53 PM
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What you said is totally wrong. You need to grab a composite book and start reading.

1. carbon fiber sheet is stronger than fiberglass mat or cloth.

2. There are many weights of fiberglass and carbon fiber sheets. Wet carbon fiber will not be heavier. All our carbon fiber hoods are lighter than fiberglass by 1-2 lbs. We can make you a super heavy one too by using more fiberglass. The fabricator has total control over the weight of the product.

3. Dry carbon is not always 100% carbon. Actually dry carbon should be referred as vacuum formed or vacuum bagged. There are many vacuum formed parts using mix of carbon fiber and fiberglass. Yeah, you can do 100% carbon fiber if you have money. But to build the thickness and strength, I rather use the honeycomb.

Chuck Huang

Originally posted by SpiritR
What SKUNKS is posting on is WET CARBON FIBER, like I mentioned, its the same weight, sometimes more due to the extra layer.

DRY carbon is 100% carbon fiber, very very very lights and about 50-60% stronger then fiberglass
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Old Dec 11, 2003 | 10:05 PM
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take a poopoo you will feel five pounds lighter
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