The expensive vented carbon fiber hoods aren't that great either for how much you pay for them.

Prices seem to have increased by 30-50% despite the yen being weak
I got my Varis for mid-teens and now it’s over $2k

For pure function, trackspec vents are more efficient

I’m no engineer, but …yeah, those triangular shapes are what are called NACA ducts and are supposed to be the best shape for drawing air in

The hood I’ve seen for both the z34 and r35 all have those positioned further forward to suck in cold air

Any opening in the rear should be designed to let hot air out

^I was convinced this makes most sense, but then at the same time, a lot of stock cars like GTR, M3 and similar, have NACA ducts positioned to the back, near the windshield.

I'm still thinking about what to do here, I'll do some cardboard cutouts and see various fitments on the hood, both on the hood and beneath it, to see where it's easiest to cut, what seems to be good position to draw the air out, and what is aesthetically pleasing.

I don't want to get too far afield down "GTR hoods" but NONE of the reputable companies (high end JDM or OEM/Nismo/N-Attack) have the NACA ducts positioned at the REAR of the hood

They are much closer to the middle, if toward the front (usually in combination with additional release vents)

I've attached images of the Z1 Time Attack 370Z (custom) as well as a Super Taikyu Z34 (Ings+1 hood).

or we can use are brains

cold air in through the front
air flow front to back cools engine/removes heat
hot air escapes up and out the back, and possibly side if you have venting there

there's really no sense in putting an air INLET at the back of the hood, unless you have a convoluted physics defying setup underneath

but i don't have an engineering degree

My favorite part of the post.

Lol, I agree. And really, I really appreciate the input. The reason I'm mentioning gtr hood is the fact that while air goes over the car in a straightforward motion, doesn't mean that in an enclosed compartment it couldn't circle the other way around. And no, I'm not trying to complicate here, I'm just considering all options. Cutting the hood is a one way street, no going back, so I'm looking at ALL aspects.
I do think it makes sense to put the inlet first, then the outlet. I just gotta figure out a way to make it look good as well.

It’s cutting a stock hood off a mass produced 15 year old car. You aren’t hacking up an f40

If heat management is a actual goal then get the track spec vents and be done with it


You are making it more complicated


This platform is old. Problems have solutions now.

My favorite technical aerodynamics drawing. https://www.buildyourownracecar.com/...erBodyFlow.png

https://www.buildyourownracecar.com/...-and-design/2/

Well....yeah but no. My car in particular is 15 years old, but it has 20k miles. It's in mint condition with first paint. It barely has any rock chips. No need to do anything stupid on it. The mods I choose and do are well thought through and I don't plan on getting rid of the car in any near future, if at all (luckily, I have the luxury of being able to keep it regardless of other circumstances). So yeah, even cutting a hood on the mass produced old car, isn't just a "let's go" process for me, sorry.

buy another hood for track use

why are we making this hard

when your goofy vents, or worse, nonvented hood results in overheating on track, it won't really matter how important you think "first paint" is

The front bumper on my Nismo is chipped from doing track days.

Racing on a dirt oval will do that. :rofl2:

The guy in front decides to ride high on the curb. :shakes head: