MikeysFC

Looking to get some opinions on vented hoods and their benefit. Ordinarily I wouldn't consider it, but living in the valley of the sun, any cooler under hood temps are better, not to mention my car tends to have a hard time starting after I drive it hard, which I've been led to believe is due to underhood temps. I'm looking at either buying an aftermarket vented hood, or cutting holes in the factory hood. I'm leaning towards modified stock for fitment purposes. My primary concern is water getting into the bay and getting sucked up by the intake, or getting on important electrical things. For those of you who have vented hoods, what precautions do you take, and what issues have you expereinced? I've attached a picture of what I'd like to do to the stock hood. IMHO, it looks classy, and seems to be functional. So...any info?

Steven622

You are wasting your time unless you a do a reverse vented hood like a Kaminari hood


It doesn't have to be a kaminari hood, but vent placement should be close to the front since that's the low pressure zone of the hood, and it sweeps air right out of the bay. I noticed a dramatic improvement after putting one on my STI and logged significantly lower intercooler temps, and noted my thermostat would work harder since it had to stay closed more often. In addition, I've driven cars with vented hoods with vents closer towards the back in the rain and I can actually see the vents sucking up rain. With the vents in the front, the rain bounces off of a boundary layer created by the vent placement.

1FastS2k

I believe that you need some sort of air diversion in front of the vent to direct the cooler air over the opening so that the hot air can escape and join the flow further downstream. As seen in this pic:





Many of the newer CF vented hoods come with rain guards that can be installed if you are worried about that sort of thing.

Disclaimer:

I am in no way an engineer or a specialist on aerodynamics.

MikeysFC

Thanks guys. The Kaminari looks real nice.

Steven622

Good news, the Kaminari is pretty cheap.

http://www.kaminari.com/honda-s2000-hood-r-c-frp-2002

berny2435

What fasts2k said. Any venting will help over stock. There are good and bad places to put vents though. I believe there was a conversation in the racer forum on this. little flap in front of a vent can help pull air out of a basic hole in the hood. Ugly but effective. A naca duct vent reverse mounted with a flap in front of it can work if used in the correct area.

I've always wondered if it would be worth while to design a hood system that would create a venturi effect. Use a naca duct in front of hood, going into small ducting attached inside hood with some slits in it The speed of the air sucks the hot air out of the compartment out a hole in the hood with a flap in front of it. Problem with this design on the s2000 hood is that the front if the hood isn't in a high pressure area.

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sidewayzAP1

Very interested in this hood... hows the fitment??? Ive never heard of kaminari???

Brutus

I have a foggy recollection about part of a post that Adam wrote some time ago that said the nurburgring guys lift the back of the hood slightly to add cooling effect. Sounds like a cheap possibility.

Steven622

If you want to really gain effectiveness, you need to seal up the bottom of your engine bay, otherwise it will still exit out of the bottom of the compartment.


As for how Kaminari fits, it fits very good I have their hood on my STI. Dropped temps dramatically over the stock crap hoodscoop.

hotlicia

I have a similar one like the one posted above. It was put on when i turboed the car and havent had any heat issues.