Hello,
I need to make a cowl type hood for my project to clear my intake manifold. I want to do a reverse cowl type setup like a lot of domestic aftermarket hoods have but better looking

I'll probably use my existing hood to create the plug and when it's finished out nicely I'll do a carbon fiber overlay. Then pop off the carbon skin, and bond that to a spare hood which will be trimmed of it's original skin. I'll leave the stock steel skeleton and latch assy. there for strength and functionality. I'll cut the skeleton where the intake manifold sits for clearance or course.

My question is, what material would be best for creating my plug? I'll be building up the "cowl" area ontop of my stock hood about 1-2" high at the highest point and about 2' long x 2' wide.

I'll keep the plug intact so that I could produce a few more cowl'd carbon "skins" if there's a market for it. This way no actual mold will be necessary. Is this a good plan?

Thanks,
Fred

 

No. That plan sounds like way too much work without a lot of reward really. I won't go into what all the problems are with this plan but here is my advice. Actually before I go into it why not just buy a fiberglass cowl and rivet it to the stock hood. I bet you could find something for $100. Then just cut part of the factory hood. If you don't like this idea here is the fabrication part. Buy some Polyethylene foam and carve out the shape of the cowl keeping in mind the curve of the hood as well. Get that bonded and formed to the stock hood. Then use some filling primer like featherfill and prime the entire hood. Then realease with mold wax and PVA for insurance and pull a mold off the structure and then build a new hood in that mold. Now you have a hood with integrated hood cowl. Pulling the factory hood skeleton from the top side sounds like a nightmare! An overlay will be very resin rich and require a ton of finish work. Then you might have the two halves come apart over time due to the difference in CTE between the carbon and steel. They will expand at different rates when heated.

 

Well, thanks for the advice. I got my idea from the Opera S2000's carbon fiber fender skins seen here:
http://www.sportcompactcarweb.....html

I figured this is the way they did them, maybe they made a mold though to produce the skin.

Seperating the hood skin from the skeleton is not hard I've done it already they just use some thick glue from the factory that has to be cut (it's like silicone or something).

I was looking for an easier way to produce a one off part that would be acceptable. I don't need to produce many duplicates just thought it would be nice if I could, not necessary though.


Modified by Fred Allen Burge at 8:37 AM 11/6/2006

 

Ok sir, after reading this post at the forum in your sig:
http://www.racingcomposites.net/unt?id=42

I realize what a massive job it is to do this correctly, if you want reproducability. The time it would take me to make the plug, the mold and then the finished part just isn't worth it in this case. So, how about this plan:

Use the foam you recommended, bond it to my stock hood (I'm thinking liquid nails or the like), carve it to shape, layer over the new foam shape some fiberglass cloth overlapping onto the stock hood. Then apply bondo, sand, sand,sand until nice and smooth, paint to desired color. Finally flip hood over and cut out the steel skin and skeleton directly under the new scoop area and carve/cut/scoop out the foam. That would leave me a "one off" hood with functional scoop for engine clearance. If it looked good enough then a mold could be taken off of it later if desired.

Sound doable?

Fred