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> VFN - Bolt on fiberglass hood - 95 Z28, Weight reduction much less than expected
z28barnett
post Jun 20 2005, 08:46 PM
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I installed a VFN flat fiberglass hood on my camaro.

The bare stock steel hood weight was 44.5 lbs.

The bare fiberglass hood weight was 34 lbs.

The weight savings was only 10.5 lbs

The weights were measured with a digital bathroom scale. With me holding the hood each time and my weight subtracted out.

The VFN site lists the hood weight as follows.

'93-97 Stock flat Bolt On Hood (with or without vents).Price=360.00 Weight=18 Ship: Truck Freight.

The stock steel hood weight checks with other sources, so I am reasonably confident in the scales.

So it would appear that the weights that VFN gives are a wild ass guess.

The hood is a good quality piece and the fit is good after I redrilled the upper hood brackets. The rear of the hood is way too high without redrilling the hood brackets. Also had to dremel areas around the hinges to get clearance

The front edge of my stock steel hood was rusting through and the area is prone to hail storms, so I am happy with the hood even though the weight is much greater than they listed by around 16 lbs.

Moral of the story is for weight reduction go with a pin-on hood or perhaps carbon fiber and weigh the hood before you install it.

Z28
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nape
post Jun 20 2005, 11:31 PM
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Yeah, bolt-on fiberglass hoods are lighter, but it seems like the companies just guess. Back when I planned on drag racing the car, I had a bolt-on Harwood 4" cowl and it didn't seem that light either.

You want to check the other way though too. I bought a pin-on fiberglass hood from Glasstek and while it's only 7lbs, it's pretty damn flimsy. Definately wouldn't want one on a street car.
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rmackintosh
post Jun 21 2005, 05:29 AM
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well the pin on VFN is light as hell.... :leaving:
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torontoZ28
post Jun 21 2005, 02:30 PM
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my friend had a bolt-on carbon fibre hood made for his 2000 z28 from RK sport. looks like a pretty high quality piece (its for a street car, not a race car), and it is pretty light. If you add the cost of painting the fibreglass hood, its only a few hundred more for the carbon fibre.
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z28barnett
post Jun 21 2005, 03:05 PM
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I posted the weight of the hood for a good reason.

As I expected several people have told me how light their hoods are, but no actual weights.

The 34 lb hood feels light to me so numbers are the only good way to go.

I posted the weight of the hood so people could decide for themselves with some accurate weight information.

I did not want an unpainted carbon fiber hood. It is interesting that carbon fiber is about 2.3 g/CC and fiberglass is about
2.55 g/CC.

That means that carbon fiber would only save about 10% if the hood is laid up at the same thickness. Carbon fiber would be much stronger than fiberglass, but not that much lighter. Since the strength of the hood is not very important and fiberglass is half of the cost it may be the better choice.

The RKSport hood is not completely carbon fiber. The cosmetic carbon fiber from RKsport and VFN is a thin layer of carbon fiber over a fiberglass base. That gives you the look, but it is really a glass hood.

You don't save on painting with many carbon fiber hoods. The resin will yellow and crack unless the hood is painted with a clear coat to protect it. VFN cosmetic carbon fiber hoods are this way.

If you are putting on a hood, weigh it and your stock hood. Then post the info here, and we will have a resource for accurate info.

Z28
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rmackintosh
post Jun 21 2005, 10:19 PM
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QUOTE (z28barnett @ Jun 21 2005, 09:05)
I posted the weight of the hood for a good reason.

As I expected several people have told me how light their hoods are, but no actual weights.

The 34 lb hood feels light to me so numbers are the only good way to go.

I posted the weight of the hood so people could decide for themselves with some accurate weight information.

I did not want an unpainted carbon fiber hood. It is interesting that carbon fiber is about 2.3 g/CC and fiberglass is about
2.55 g/CC.

That means that carbon fiber would only save about 10% if the hood is laid up at the same thickness. Carbon fiber would be much stronger than fiberglass, but not that much lighter. Since the strength of the hood is not very important and fiberglass is half of the cost it may be the better choice.

The RKSport hood is not completely carbon fiber. The cosmetic carbon fiber from RKsport and VFN is a thin layer of carbon fiber over a fiberglass base. That gives you the look, but it is really a glass hood.

You don't save on painting with many carbon fiber hoods. The resin will yellow and crack unless the hood is painted with a clear coat to protect it. VFN cosmetic carbon fiber hoods are this way.

If you are putting on a hood, weigh it and your stock hood. Then post the info here, and we will have a resource for accurate info.

Z28

...well one day if I am bored and have the car out of the trailer to wash it...I will weigh it....

I DO KNOW, that when I took the stock hood off, I STRUGGLED to carry it by myself without dragging it along the floor....PRETTY F'ing HEAVY....and I can take the pins off of the VFN and balance it in ONE HAND with no strain to reach under the hood now....they quoted 12 lbs.....it IS NOT more that a few lbs. more than that...... (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif)
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torontoZ28
post Jun 21 2005, 11:11 PM
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QUOTE (z28barnett @ Jun 21 2005, 11:05)
The RKSport hood is not completely carbon fiber. The cosmetic carbon fiber from RKsport and VFN is a thin layer of carbon fiber over a fiberglass base. That gives you the look, but it is really a glass hood.

wow. i didnt realize that! i should have asked him to weigh it before installing.
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firehawkclone
post Jun 22 2005, 02:52 AM
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It's not a VFN hood, in fact i don't know who make's it, but my Firehawk replica hood is 50lbs (IMG:http://www.frrax.com/rrforum/style_emoticons/default/blink.gif) with all bracket's on it and half the hing!

Maybe i should get a stock hood (IMG:http://www.frrax.com/rrforum/style_emoticons/default/rotf.gif)
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NickS
post Jun 22 2005, 05:35 AM
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FWIW, the Blaine Fab carbon fiber hood on the AI car weighs 7.5lbs with the wickerbill in the back.
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z28barnett
post Jun 22 2005, 11:34 PM
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QUOTE (NickS @ Jun 21 2005, 23:35)
FWIW, the Blaine Fab carbon fiber hood on the AI car weighs 7.5lbs with the wickerbill in the back.

That would be a pin on hood I assume?

Thanks for the post and the weight, might be good to give the basic type of hood, pin or bolt on ect.

Thanks

Z28
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nape
post Jun 23 2005, 04:33 AM
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QUOTE (NickS @ Jun 21 2005, 23:35)
FWIW, the Blaine Fab carbon fiber hood on the AI car weighs 7.5lbs with the wickerbill in the back.

Is that hood fairly rigid?

Like I said earlier in the thread, I have one from Glasstek that's fiberglass and it weighs that much, but it seems pretty flimsy.

How much do his CF hoods cost?
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