Custom glasfibre hood.

[Vekke]

I have started to manufacture glasfibre hood. Old steel weigths 12.7kg and I hope the new will weigth under 7 kg. Hood will have windscreen wiper deflectors and air outlet in the front on hood. Hood will be attached in the same way as original.

Materials are glasfibre, polyester resin, glasfibre-padding and polyfoam.

1. I laminated 4 layer of glasfibre on top of the hood. I will fill out the hood gaps on the front and sides...
2.Then I put glasfibre padding to the rear latches so i got skrew places for rear attachement.
3. Put in ready in shape cutted polyfoam on top of glasfibre hood. Attached it with 4 srews.
4. First shapes with aglegrinder.
5. then with manual hand tools.
6. plastic tape on top of foam, so the foam would not meld under polyester resin.
7. 3 layers of glasfibre mat.

Pics can be found:

seatti - Windows Live

Next step is strengtening ribs inside hood and plate for front latch. And the final touch is the air outlet.

I will paint the hood with brush to red...

[skyl4rk]

Looks good, that is a great idea.

What do you think is the best shape to divert air over the windshield wipers? Is a large gap between the wipershield and the windshield OK?

[Vekke]

I am not sure if that big gap is best choice. In normal cars the gap is smaller but maybe because there is a visibility issue also to consern. Now the edge is paraller to widscreen agle. However its eeasier to grid that smaller if tuft test proves that gap too big.

[Istas]

Hey, looking very nice! You're really doing some good work on that car. I would not have the patience for working with fiberglass.

Have you tried different positions with the front tire deflectors?

[Vekke]

I moved their position 1 inch inwards, because most cars have them like closer to that position. I think the position is usually the outside corner near the tire centerline :/

[Istas]

Actually, I think slightly offset towards the center of the car is where they should be, about, since the airflow under the car there is already angled toward the outside of the car. Putting the deflector directly in front of the tire would push air out from the side of the car, which would create more drag.

[vtec-e]

Thats some nice work there Vekke. Did you spray some release agent onto the hood before you laid the fibreglass onto it? You could mould the underside of your hood to make ribs for it. After removing the hood and turning it over of course.... Then bond the two parts together? Then it would look like a normal hood, only lighter! I have no real experience with that stuff so forgive my ignorance.

ollie

[Christ]

You can just wax the hood... or tape aluminum foil to it before you lay the fiber down. As far as the bottom of the hood, you don't need all that ribbing under there... you can get away with a basic framework, which will save weight.

With glass, it's weight comes from the amount of resin you use, and the type... the more unnecessary work you put into it, the more resin you have to use, and the more weight you end up with.

[Vekke]

I didint use any release agent in the upper part of the hood!. There isnt any need because the paint surface is so smooth and there isnt any big shapes... I could do the inside like vtec described above but like crist said I dont need that much ribs.

The goal is to make hood shaped as fuel efficient shapes as possible but at the same time save some weigth. My weigth goal is 7-8 kg so around -5 kg of weigth savings.