I did the K&N FIPK cold air system, easy install, no issues. Haven't dyno'd it for difference, 10-15 is small, but I figured every lil bit helps, plus I feel like it's a bit more responsive to throttle now - but not sure if that's real or perceived. I have the XMetal TB to install, I too think the K&N with TB is going to make a nice combo - together maybe 20rwhp or more & even better throttle response. I just need to take an hour or so & install the TB.