by RomanV » Mon Apr 19, 2010 12:34 am
Is it not fairly irrelevant on a turbo car, where the air is getting heated up a whole lot by the turbo anyway?
It's only how cold the air is entering the intake runners that's really relevant, and thats more determined by the turbo and intercooler.
More value on an NA setup I'd say, especially when combined with drawing air from the high pressure front area of the car, reducing pressure loss.
Helmholtz etc is pretty well irrelevant for an air filter box, for the size of the box and the size of the inlet/outlet pipes it only work at like 1500rpm or something like that, I cant remember the exact figures. But when I did some of the maths on it a while ago, you'd need an air filter box either impractically large, or impractically small to get any resonance affect from it. Having a resonator box inline with the intake piping (As per almost all cars factory intakes) is the most practical way to change resonance characteristics of intake tract.
IMO the best way to design an air filter box is pretty much as per the ARC ones, have a nice full rolled bellmouth protruding clear from the edges of the box, with as bigger volume as practical after the filter. And having the intake on the other side of the box taking air from in front of the radiator panel, high pressure area of the car.
That's something which wont show any gains on the dyno, but will definitely help while the car is at speed.
There are some sweet articles on Autospeed.com about how to test effectiveness of standard intake components, most things I've read that have been written by Julian Edgar have been awesome.