Importedpower

Alright, to start off, I am an Electrical Engineering student at USC, and i've been pondering going up to get my hood vented by a member here later this summer. I am an avid supporter of FUNCTIONALITY. I know that from a stop, the vents will keep my FIPK sucking in some cool air. However, while moving, how functional is the hood really? I still want to do it, but i have been measuring and looking at several forms of NACA Ducting/louvers. Here is where my posts purpose comes into the light.

With the oem hood, uncut, the air is directed through the front bumper, around the radiator, and into the bay, which can escape out the bottom, and the windshield side of the hood while in motion. Check-

With the OEM hood, Vented, the way the hood is shaped, the hood's vents will pull air in, but, with the air coming in from the radiator etc, how much air would it let in, or would it force hot air out? (((((Is the goal of venting to VENT hot air, or induct more cooler air?))))

I am working on some rough sketches to see if that clears up what im saying.

GOAL: To find a setup of Naca ducts, louvers, or other modifications that could direct MORE air in and out of the bay, and keep it cooler in the bay, as well all know, a cooler bay is a happier bay. (also looking into rain details/covers, if i figure something out, i will gladly post all templates, measurements, and products/companies i used for others to make their own)

Sideways

Start by removing the weather strip for the back of the hood that runs in front of the wind shield.

Fight On.

Importedpower

I am gauging how the car works Stock with heat dissipation, vs say an under tray etc. From various sources, and common sense if you have ever been under a car, more air escapes out the bottom than the top. And one would imagine that since Cold air is Denser than warm air, that you would want the cold air going into the car from above, to counter the "Lift" effect when traveling at speed. similar to how a front splitter would function.

So i think my primary design would be 3 various sized naca ducts (or similar design) mounted on the hood, and by function, they would force air into the bay, and "flush" the heat out of the base of the bay more efficiently that simply putting a vented mesh. Granted, its much more cooling that would probably ever be needed by me, unless i go turbo that is.


The ducts should force enough air at speed (on the right side of the hood) to push the hot air out of the bottom of the bay and under you car. This hot air is less dense and would likely produce a small amount of downforce, and significant cooling considering it would blow straight past the header and likely throw a hood bit of that radiant heat out of the bay and out the back of your car.

EDIT: Also, trying to make a design in which you can simply unbolt the sections you dont want, but this would be a fixture in the inside of the cut area, sort of like a mating piece between the two. Also help with rain since you could cover them back up if needed

JDMpearlwhyteZ

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Importedpower

I have a basic side/top view drawn up with the basic vents and flow, im working on detail the second with my ideas. However, due to the angle of the hood cuts, i may have to use a modified naca duct, make it scoop at an angle due to this issue. Also, for those of you with undertrays, as i know gp fabrication is working on an affordable one now, i will take this into consideration after the initial designs

Current Hood Designs used by other companies seem to vent heat out of the top of the engine bay. IE:
J's Racing
Chargespeed
Seibon
ASM
ETC

All of these hoods share a rearward vent, which would direct air out of the bay, instead of into the bay.

So here is my question:
Should i design something to push more cool air into the bay, or something to allow for the heat to better flow out? both are easily achievable (sort of) but i just wonder why they don't push air in to keep it cooler and allow it to flow out from under the engine like it does from the factory?

Awaiting input =D

vaj303

I'm curious to find out what the engine bay looks like after running into an unexpected rain storm. And how would you wash the car if you had a vented oem hood...wouldn't the bay get all wet?

Importedpower

Everything in your engine bay is waterproof except the intake filter if you have an intake. In my case, injen makes a very nice "heat shield" you can flip over the intake cover the filters, works for aem aswell. S-factor has a diy on the rain cover for his FIPK, im going to do the same as he did there

ever driven in the rain, then popped the hood to see the water marks all over everything? water gets in here and there anyways, plus kicks up from the bottom side of the engine bay.

Honda007

Most companies attempt to vent air out of the engine bay, to help create negative pressure (kind of like a vacuum) this in theory allows more air to run through the bay. If you ram more air in it will equalize pressure between the front of the bay/ radiator area and the actual engine bay area and air flow will be stagnant, this assuming velocity remains constant. There is a bit more at work, but I'm trying to keep it simple. I may be wrong.

Importedpower

The way i see it, and i can design the vents either way, but as the fans blow at the radiator, and air is induced from the front of the bay, any vents along the top would simply take some of that air out of the bay before it went fully across? i will scan some of my sketches in a sec and post em up

S~Factor

I have done over 65 vented hoods and all are very happy with the result. I have one guy that makes 750 rwhp and he did a back to back comparison of before and after the vented hood. His engine bay temp gauge always read around 210 degrees, on his drive home after venting the hood, his temp gauge was around 195 degrees. Venting your hood DOES work.

I think it dissipate heat more than suck in more air from above. You can see this when you are stopped at a light after the car has ran for a few minutes.


This is an old picture of my engine bay but you can see the air heatshield here.