I looked at the specs of the two different kits from K&N before I purchased mine. Looking at K&N's dyno chart, the 57 series kit starts to increase from stock HP around 3700 rpm, on up. Even though the power curve seems to start at a lower rpm range on the 77 series , I dont think the rpm point of increase matters too much in a 1/4 mile run. I ran well above 3700, through several gears, in the 1/4.Npath wrote: From what I've read from K&N, the model you have is best on highway/freeway driving. You don't really feel any increase to power till you reach about 5000rpm's.
The 77 series CAI by K&N gives quicker HP gain after 1600rpm's. I have the 77 series but haven't installed it yet. This series has a polished aluminum tube, not plastic.
Let us know about your 77 when you get it in. Post some pics too!