Originally Posted by BEAMERBOI
Just drove it with new mod and I can tell the difference it has more tork and the turbo's really sing...... Sweet! Defiantly can tell a difference in power. not a hole lot but it is much more responsive and has zero lag.
Glad to hear!
I swear by K&N (oil-soaked cloth fiber) filters myself - they have always given me both more performance and better mileage.
The downside is that they do let slightly more particles through - there is a tiny amount of pitting in the pistons of my old 4.9l engine after ten years (with the same filter!), but not enough that it is inconsistent with ten years of use, or affects anything.
Oh, and the K&N filters aren't available for the X1 35i yet. So your mini-review is useful info!