I recently put on a K&N FIPK and the gibson SS cat back. The two totgether sound good and I can feel the improvement. Now that I have those done I want to do more(seems addictive) I was wondering if the throttle body spacer does anything and if it will still fit with the FIPK becauce it would push out the intake a little more. Oh, and I figure that I am getting between 10-15 more HP. K&N has the dyno on a 2000 X and it show around 6hp gained I figure with the exhaust is about the same and the two together maybe a little more.

Pete, i've only seen one X actually use the TBS in person, the owner said it made a difference but most people say no. I doubt it would increase HP, the guy who I know who owns one just said it was increase in throttle response. So it is up to your own judgement. Otherwise it sometimes can get annoying hearing the whistle from the TBS especially offroad.

I've got one on my X.
Now I don't think it did anything BIG in performance.
But it does give the X an open 4 barrel sound.

i have a tbs...i dont know if it makes much of a difference...it does fit with the fipk 2....an sob to get it on though...gotta push damn hard to move the intake out of the way...but its possible...oh and it makes an annnoying hissing noise when you press on the gas like half way