i can give you examples of how they work if interested....... well il do it anyway.. ha ha
i have had both cone filter and air box and have measured BHP on cone yet to do airbox..... im lucky that a close friend of mine owns a rolling road and if im nice enough lets me use it time to tim ha ha ha.
my 1st 3.0 track car had a cone filter induction kit....... it sounded all very nice yes, and did increase bhp by 3 bhp at top end ... lower down however it suffered a 4bhp loss untill about 4100rpm....... now all i did was fit a filter and didn't change air feed simply used omega standard 1................. so yes i would fit one for noise and top end...... and just to add never had any problem of oil on maf at all.... :-/
the latest track car uses an air box with piper X panel filter... i have also taken trumpet out from top of air box ...... and original cold air feed replaced with 600mm x 80mm RAID induction Tube that fits in hole perfect and have place intake in lower half of bumper grill .....
look through lower bumper by tow eye
Now yes i dont get any noise but it feels noticibly better ... i haven't yet however had it tested but aim to either later today (tuesday) or tomorrow.......
hope this all helps.
