Hood Scoop? Need suggestions

[dslocal]

i wish i had figured this out before i went and cut into stuff.
Anyways It would probably just be easier to get another hood, There is actually a white supra at the junkyard now so I might go get that one...
Anything else I should do to the hood while I'm welding on it?

And thanks for the photoshop by the way^

 

[dslocal]

Yeah like that ^ but with the naca duct as forward as underhood space will allow.

the only thing I really have to watch out for is the intercooler pipe coming off the rear turbo. I will see what I can do.
Have any idea of approximate demensions I should use for naca duct?
Thanks again. SM kicks ass!

 

[Neodeuccio]

the only thing I really have to watch out for is the intercooler pipe coming off the rear turbo. I will see what I can do.
Have any idea of approximate demensions I should use for naca duct?
Thanks again. SM kicks ass!

Check this out: NACA_Profile_Calculator.xls

This should allow you to measure how much space you have available, then calculate the the maximum size duct that will fit in that area while still maintaining the correct proportions.

And yes, SM is fucking awesome! I just hope that in some small way I help. Good luck!

 

[supraman7mgte]

okay,Q;do you still have the plastic underliner? just curious if adding an air inlet on the hood will affect the abilty of the other duct to remove engine heat.i just figure that just the air coming in through the radiator area across the the engine and then OUT the hood would be best.by no means am i stating that my idea is the best,i just left it to best guessing.plus it looks kinda cool.

 

[Neodeuccio]

That's a good question. Far beyond my ability to calculate. I never was any good at fluid dynamics...

 

[Canuckrz]

Hm, good point, but as long as the exit vent is large enough the pressure change shouldn't be significant enough to disrupt the flow to the rad/ic. I can't really say for sure though.

Personally I'm only putting in an exit vent because I'm going to be running a cai so increasing the flow to my IC/rad is what I'm going for rather than getting air to the turbo/in-bay intake. But that being said my plan is much different than yours, though you could run some kind of cai/air box easily as you already have a ffim so no ic pipes to get into the way; and then you could just blanket/ceramic coat the turbo's/downpipe/exhaust manifold to decrease engine-bay heat and the turbo would likely spool faster because it would keep the egt's high and because gases expand as they're heated yadda yadda yadda you get where I'm going with this.

Its a bit more complicated but likely more efficient. But to each his own; 1 size doesn't fit all; etc etc.

 

[Neodeuccio]

yadda yadda yadda ...etc etc.

That was a really good post. I approve, both on the technical parts and the babbling.

 

[dslocal]

ok well thanks for that link, Neo. Big help. Anyways to supraman I do not have the plastic underliner thingy anymore, Mine was all torn to hell from the previous owner so I am making a new one out of some 20 ga aluminum I got from a street sign. Hahaha.
And as far as a could air intake goes or the air box, I already have a piece of 3" tubing feeding in cold air from the right fog lamp, I just need to mount it, But I am still trying to lower intake temps because lower temps equal a cooler charge and more power.
Btw the manifolds, hot sides on the turbos and the downpipes are already cermac coated...

One question though, How does the air normally flow on a stock mk3? Through the front grill, intercooler, radiator, Then where? Out the bottom?

 

[Canuckrz]

Not completely sure, which is why I'm doing my hood like this to give it a better path http://www.supramania.com/forums/showpost.php?p=711272&postcount=33

It will give the air coming off the fan shroud a better exit so it promotes more flow through the IC and rad; and it should suck some of the engine bay air out while its at it. Besides that its simple, clean, and looks like sex.


Here's something else you might be interested in, its a silicone gasket which helps block the heat that the intake manifold would absorb from the block normally: http://store.driftmotion.com/static/i-heatshieldinggasket1jz.php

Also I'd get the ffim and any IC piping inside the engine bay ceramic coated as well to help prevent heat soak.

I'd make an air box for the filters regardless personally, because once you come to a stop that 3" pipe and hood vents will be near useless to the air intake and it would go back to sucking in engine bay air. Personally I'd rather have a setup that got outside air all the time, more predictable intake temperatures, etc etc...

The modifications you're looking into are much the same as I'm planning to do myself, which is basically make the engine/air intake as cool and efficient as possible rather than just stuffing more fuel and air in. So I've been looking into a lot of these various things for a little while now. Good luck with your build I'll be interested in watching it as it progresses.

@Neodeuccio

Thanks man, nothing can be technical without some babbling involved eh? :biglaugh: