how much does a cowl hood really help?

[seannz28]

I am pondering getting a 4 inch cowl hood to compliment my new engine....but what good will it really do? is it all just cosmetic? apperently it creats a vacuum near the windshield and that draws more air into the air cleaner...is this true?

[Benm109]

A cowl induction hood can give you cooler air which is better air (as you probably know). You have to make it functional though by making it so that the vacuum is created from your air cleaner. You can fab some sheet metal around your air cleaner assembly so that the air cleaner is blocked from sucking in hot air from the engine and can only suck in cooler air from the cowl area. If you just put on a cowl hood, though, it will allow for cooler air to enter the engine compartment. I hope this helps, but I can't explain things very well.

[FORMULA FANATIC]

As above............. if you can keep ONLY ram air into the throttle body and no engine heated air, You can expect 5 to 10 HP increase above 60nph or so.

Phil

[Injuneer]

Re: how much does a cowl hood really help?

Originally posted by seannz28
I am pondering getting a 4 inch cowl hood to compliment my new engine....but what good will it really do? is it all just cosmetic? apperently it creats a vacuum near the windshield and that draws more air into the air cleaner...is this true?

Actually, there is a high pressure zone near the intersection of the hood trailing edge and the windshiled - not a "vacuum". It's the increased "pressure" that helps push air into whatever is connected at that point.