2G Hood vents!

[greyforestgst]

well, the car's running great, nothings broken, everything is in order. i figure its time to do a couple of the little mods i've been meaning to do in my spare time.

i'd like to cut a couple holes in my hood ala lancer evolution, mask it off with grill mesh, then put a fan or two below there wired to ignition to blow hot air up and out of the engine bay. cutting the holes is no problem really; i'd mark out the shape and size of the holes on the bottom side of the hood with sharpee, drill a hole, then sawzall to get a rough portion of it gone. die grind to the sharpee line, then dremel to smooth everything out. if you look on the underside of the hood, you can see about where i'm wanting to cut. i don't want to mess with any of the ribbing, so there's pretty much minimal flat parts to work with that are just sheetmetal.
im not sure how securing the mesh would be accomplished. maybe just some high temp adhesive would do the trick. spot welding would be very nice, but i don't have access to any arc welders. the fans would be pretty easy. using short screws i could make use of the thick ribbing along the outside of the hole to secure them without much trouble. wiring is also no problem, simple just to run down the hood, then attach to the wiper nozzle tubes as they run down to the firewall. from there its just a matter of tapping in to an ignition wire and grounding.

constructing it would be a fun test of my skills, and would imo look kind of neat and be functional as well. a picture would help here, but im extremely lazy. you can see pretty easily what im talking about though, and you are limited to two holes either over the turbo / intake pipe / radiator, over the valve cover, or over the intake mani.
my problem is getting water on any of those things mentioned. 99ish subarus, of course the evos, and people with those aftermarket hoods all have open gaps to the engine bay. how do they get away with it, without rusting, shorting out water-sensitive electronic bits, etc.?

 

[greyforestgst]

here's the evo's
no water trays, no fans, just nothin.

 

[DrZiplok]

You pick (carefully) where the holes will go, then test to make sure that no water gets on anything expensive.

For a DSM, you really want the hole in front of the head, over the exhaust manifold, to suck more air through the radiator and out over the hood. There's not much in that area that's going to be upset if it gets a bit wet.

 

[redeclipse97]

You need a W vented turbo hood, it pulls air from the front of the car like a cowl-induction hood to reduce underhood temperature right over the exaust manifold. No goofy fans and it works and looks good. Also instead of adding weight, you'll be reducing weight.

 

[greyforestgst]

yeah, except i plan on spending maybe $40 at most, and adding 5 maybe 5 pounds...

i dont think fans running off ignition would be too goofy...painted black you could barely see em. just feel the hot air blowing out over them


over the turbo looks like it would fall on the least electronics. im still curious as how the evo gets away with it though.

 

[greyforestgst]

ttt

 

[greyforestgst]

sorry to keep bumping this, but id really like some sort of confirmation that cutting a couple vents in my hood will not rust / destroy some part of my engine bay.

 

[DrZiplok]

You don't need the fans, especially if you can create some minor suction over the holes.

Properly-designed hoods do this by angling the vents so they face rearwards. Aftermarket vents achieve the same thing; see eg. the Carbontrix vents.

A little water on the exhaust side of the engine isn't going to be a problem; it gets plenty wet when you go through a puddle as it is.

 

[DSM_Drew]

I agree that the fans would be pretty useless, unless your car sits at idle in traffic in hot whether for long periods of time. Heat rises naturally and when driving air would flow through the front and out the vents.

I've been thinking of doing this with a spare hood I have for my car. I think I'm going to get one or two louvered hood vents from RRE. The vents are not on their website but they do sell them.