This tags on to the earlier thread about trying to design the hood so that it releases more heat. So here is the upshot of my research and thoughts.

I am going to put a set of rear facing louvers in the hood, exactly where the old forward facing hood scoops are. Here is the link to the product I have found that looks perfect for what I am trying to do here. http://www.raceace.com/products.html

The large ones will cover the area where the old scoops are exactly, thus requiring minimal body work to make it look OK.

However, the existing fiber glass hood has damage where it was allowed to close too fast before I installed the lift gate style hydraulic lift cylinders. The cracks are right over where the old radiator filler was. There now are two inherent, 6" spider web shaped cracks that you cannot simply bondo over. The cracks have shown up again later as the paint shrinks.

I have three choices here.

1. I can re-install the steel hood which weighs 30 pounds more than the glass one, with the vent in it, although I would likely go with the smaller vents if I use the steel hood. The steel hood is not pretty at this point. I would have to clean, prep and paint it, in addition to adding the vents.

2. I can install the vents in the existing hood, and live with the cracks. From 20 feet away you do not see them.

3. I can buy a new AAR hood and start over. This costs $500. It seems to me this is too much money to save 30 pounds.

I can save 30 pounds by either spending money, or living with the cracks.

I suppose I could live with the cracks. The hood scoops are actually beginning to crack loose from the hood surface because of the expansion and contraction of the plastic with the intense heat of the turbo. The current set up is not a viable, long term thing. I think the metal hood, with the aluminum louvers will be the most stable, and least vulnerable to the underhood heat this turbo produces.

I guess the steel removed where the louvers will go will reduce the weight of the steel hood some. Maybe a pound or so. Has anybody tried to reduce the weight of a stock hood with lightening holes in the under bracing? Can you remove some of that entirely? I was thinking of removing upper surface and bracing entirely where the vents go. Anybody think that will leave the hood too shaky and weak. It seems it would be at least as strong as the fiber glass one with a big hole cut in it. There would be ways to brace it underneath with aluminum if I remove the steel bracing. If I use the steel hood, I will possibly go with counter sunk #4 screws instead of pop rivets.

Another advantage of the steel is that I can do the work off the car while still retaining drivability with the glass hood, and swap them out in an afternoon or so.

Are there any thoughts on all this? Thanks

Sam

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What about the fiberglass hood that's re-enforced with some extra fiberglass.....

I'd re-enforce the cracks and what your best quesstimate of other weak areas are. (add the fiberglass on the underside)

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Before I installed the current glass hood I reinforced the underside with a glass duplication of the stock hood undersides. . Do you know how to make a good repair of crack damage to a fiberglass body part? Do you dig down and lay glass mat in the damaged area? It seems there is always going to be an edge of some kind where the repair material meets the old, and that this will show eventually.

This hood is from Unlimited, which is no where near as nice as AAR parts according to information posted on other forums about this stuff. The body work that was done originally to straighten it out eventually showed up as well. Unlimited obviously did not expect their users to care about aesthetics, which I can never completely abandon.

But I hear you. Maybe it is worth a little work on this hood to save 30 pounds. What about the idea of covering the top side of the hood with vinyl wrap of some kind? Maybe even carbon fiber looking wrap. It would have to go on before the vents panels. I wonder if that stuff would disguise the cracks, or even heal them a bit. There are some companies around here that specialize in wrapping entire cars.

Sam

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Years ago I was obsessed with losing weight in my Duster. One of the things I experimented with was lightening the stock hood. After cutting some of the bracing it got 8 pounds lighter. Since that wasn't enough I removed the springs, replaced the latch with two hood pins and removed more of the bracing keeping only what was on the very edges. When all was said in done I saved about 35 pounds.

On about the third pass I made the hood buckled up in the middle of the front as the pins were only on the outside edges. It looked like a giant scoop for about a second until one of the pins quit. About a millionth of a second later the other pin took a powder and the steel hood folded back covering the windshield completely. This was just before the traps and that car ran about 110.

My efforts got me almost 3 hundredths, but cost me a straight hood and a pair of underwear. Some how the windshield didn't break and it only put one small scratch in the paint on the roof which actually did buff out. The next hood I put on had all the bracing.

30 lbs will get you about 0.05 sec in the 1/4 on your car.

Some bracing and springs could be removed from steel hood and not get catastrophic buckling as Wayne described. Might be worth it to deal with turbo heat.

Lou

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Home of Slant6-powered fun machines since 1988

If heat is a problem with your fiberglass hood, would adding some foil insulation to the hood above the turbocharger be of any help?

Frank, I've actually got a pretty decent heat shield on the turbo now. Thanks for the thought though.

SAm

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