New hood design, want feedback.

[spacemanspif]

What you are basically planning is a cowl hood. The proper term for these is "cowl induction hood" as they are used heavily on cars with carburetors because they take advantage of the "bubble" where the bump meets the windshield in order to suck ambient air into the air cleaner. If you want to use it for aero purposes you'd need to seal the cowl to the windshield (or get it very close). I have a 3 inch cowl on my Monte for intake clearance and taped over the vents that allow air back into the engine compartment. If you were to do the "double hood" plan and cut holes in the "under hood", you could run the risk of pulling air INTO the engine compartment, negating the exhaust plan you have. Its my understanding that if you want to remove air from the engine compartment it is best done on the far corners of the hood or even through holes cut in the fenders.

Commercially available cowl hood for Civic:


Buick GNX had some engine heat issues due to the Turbo. Buick added vents on the fenders to exhaust more heat from the engine compartment. It's been said that sitting in traffic with the fan running, the heat coming from those side vents could burn the hair off your arm that is resting on the door when the windows are rolled down.

[YeahPete]

I don't think that will help any. Like someone else said, "biggest gains are in the rear." It's not worth the time and $$ that will be spent.

[whatmaycome14]

Originally Posted by tvbd56

One thing that I see is that it would act as a windshield wiper deflector. Instead on the air hitting every single part of the windshield wipers, the air should travel above the wipers.

The windshield wipers would be completely removed in order to allow contact with the windshield itself.

[freebeard]

I consider aerohead's response in this thread authoritative.

http://ecomodder.com/forum/showthrea...tml#post408459

[whatmaycome14]

Originally Posted by spacemanspif

If you want to use it for aero purposes you'd need to seal the cowl to the windshield (or get it very close).

Yes, that would be the intended design.

Originally Posted by spacemanspif

Its my understanding that if you want to remove air from the engine compartment it is best done on the far corners of the hood or even through holes cut in the fenders.

Yeah, I'm thinking this as well.

[whatmaycome14]

Anyway, the impression that I'm learning is that the high pressure zone isn't really hurting anything, so I'm trying to "fix" a problem that isn't there.

However, vents and louvers on the existing hood should help with air flow through the engine bay, but that is a topic for a different day I suppose.

[UltArc]

I think you should try it. Some wax paper, great foam, and a wire coat hanger could make a passable mock up.

I get what you're saying, more so in regards to avoiding the wipers which another user mentioned. Worth a shot, least you can do is teach us a real world lesson

[jedi_sol]

Hey, you're pretty good at google sketchup...would you be willing to make a 3-d model of my Sti with a Kammback?

[aerohead]

Originally Posted by whatmaycome14

Not to the extent that I think I need to apparently. However, the high pressure zone would only have an impact if the rear of the hood was not sealed. I'm thinking that if it were sealed against the glass, then the air would have no choice but to continue to flow over or around the car, no?

I taped closed this entire area at Bonneville and measured no change at 105-mph.

[whatmaycome14]

Originally Posted by jedi_sol

Hey, you're pretty good at google sketchup...would you be willing to make a 3-d model of my Sti with a Kammback?

Sure thing! I'll have to use a model from the 2009 year. Nobody has created a 2013 version. It should still work though, right?

http://smg.photobucket.com/user/mkii...STI%20Kammback