CAI hood vent?

[Tangent]

I know that the trapped air under the hood can generate lift but I don't think it has anything to do with the temperature of the air for practical purposes. Just think about how massive of a volume of hot air a hot air ballon needs and how little weight it can lift relative to that. Having hot air trapped in the under-hood area vs cold air probably would work out to a difference of half an ounce of lift...

I'd maybe consider venting my hood if I start tracking the car alot and have cooling issues. (There are plenty of better solutions to that problem though) Vents just aft of the radiator are great at extracting the hot air from behind the rad and promoting much faster air flow thorugh it. That what those hoods that take the big dip before the front edge are for. Plenty of ricers are using them for looks now, but lots of race cars have them as well. You can see them clearly just inboard of and back from the headlights on this Maserati racer:

[uofom3]

one of the main reasons that louvers are used on hoods is to dicipate heat. This is not done to cool the air on the intake path, or to create a "cold air intake" but to reduce the amount of heat tripped under the hood to reduce lift. Heat rises - the cooler the engine compartment can be, the less lift on the front of the car. Properly placed vents can help the rediator get better air flow and possibly reduce overall under hood temps, but to achieve what you are talking about you need to find a way to channel the air into something that will allow the air to not be turbulant when it reaches the actually intake. With your proposed setup, you'll have increased drag, imbalance the car at speed, and create a seriously turbulant air enviornment under the hood. The reason the factory uses stock airboxes with the little trumpet that sticks behind the bumper is because the air is not turbulant (read low pressure) in that part of the engine bay. The motor is able to intake more stable air - and something that is stable is easier to get - easier to get ='s a larger quantity, and the engine is happy. I run a factory "evo" airbox on my m3, and i have also had a cone filter. The car runs noticeably better and quicker (especially if its warm outside) with the factory airbox, and a factory air filter. The ultimate best solution to this problem is to remove the high beam on the drivers side and use some sort of ducting to pipe air directly to the filter. The tubing channels the air properly, and alows truly cool air to be taken in at the filter. I have seen this applied and it really does work. a really good writeup on this topic can be found at :

https://www.e30m3performance.com

[nefarious7907]

you could try and make a functional m3 fender vent and that may or may not be considered ricey but it is still a BMW design.

[Jand3rson]

Holy old thread, Batman! :shock:

I've long since abandoned this idea.

[B2ThaZiZza]

I was this foam like thing at this shop called AJ-USA(ajusa.com)and it covers the airfilter on CAI's, it doesnt obstruct the flow of the filter but prevents dirt,water,etc from being stuck on the filter. I dont remember what its called or who makes it but looks like a neat thing to get if your considering to put a vent on your hood.

[gstuning]

It seems that there are always those who don´t want to help or whatever and it really is getting boring,

Anyway,
on you idea,
If you want to remove extra air from the engine compartment then removing the heater fan cover will allow air to go out from where the wipers are,

Also remember, that the amount of air needed to be removed is amazing,
so that will not work,

To begin with the E30 TB is 62mm wide, if you measure the little plastic tube that goes on the air filter box from the headlights how big is that?
If you are going to be running a M20B25 NA then building a stock looking intake system with M30 sizes is your best bet, that will work better then any form of CAI.

as I have said before , With great challenges comes great engineering
so keep on thinking,

[big headed junior]

I think your best bet for a hood vent is to get a catolog from chassis works they are a drag race company they make a killer scope that sits flush with the hood and you can get one in either 6 or 12 inches long

[Streetspec_iS]

tilt your hood. lots of FI guys i know do it here. nothing to do with CAI, it just lets the heat get out preventing saturation, esp on FI cars. it looks ghetto, but function over form, u know.

[Nick325is]

What about adding a rain gutter so yoou dont get water in your intake.



Paint technical diagrams...

is it just me or does the lower right picture look like a penis in a picasso painting? :P

Its not just you

[PanamaE30]

What about adding a rain gutter so yoou dont get water in your intake.



Paint technical diagrams...

is it just me or does the lower right picture look like a penis in a picasso painting? :P

[Matto]

What about adding a rain gutter so yoou dont get water in your intake.



Paint technical diagrams...

[Skafrog]

yes, it is. Unless you drive through a lake, you wont suck enough water past the intake runners (where it evaporates) to matter.

[MinkerVR6]

Ok, let's say thay we all agreed on putting a scoop, well not a scoop, a big ass hole on our hood above the CAI. What about water? I believe that is a more important aspect than if it would give you more performance or not. I'd be afraid that it would get soaked and my engine would lock up. But hey, that's just me....

[e30Matt]

this looks like some sort of vent, like on the benz greg posted. but why on the passenger side? turbo maybe? or it could be something other than a vent (sticker maybe)

Those look like stickers to me, but hey, whateva.

I like the flow-through idea.

[Skafrog]

First of all....

The myth of RAM AIR is exactly that. A myth. Someone did the calculations... The super cool headlight delete mod would only provide like .1bar positive pressure at something like 120mph. Same with a brake duct vent.

It wasn't even .1 bar, it was like a .2-.4 HP increase at a 100mph or something like that.

Can you dig up the sheets for that possibly?
If I can gain .4 HP just from doing the headlight mod while on the track, hell yes.