Does anyone have an opinion and experience about adding a K&N filter to an X with a factory supercharger? (2002 SE/SC)

At first, it seems like a good idea, but then I don't know. Too much airflow with a supercharger could have an opposite effect.

I already put a Flowmaster muffler on. Adding the K&N filter as well might be too much.

Any thoughts?

Which K & N filter do you want to know about? K & N has filters for the S/C so its fine.

I have the K&N FIPK2, aftermarket muffler (performance), and 2.3" pulley on my 02' supercharged X, all with no problems for the supercharger.

As far as too much airflow causing problems with the supercharger...there is nothing there for a reduction in inlet restriction to damage.

FWIW I gained about 1Lbs of boost by switching to the K&N filter.

just beware of oiling...too much and it will affect your MAF sensor and by modifying your air intake, Nissan will not, I repeat, WILL NOT honor the warranty if your sensor goes bad...I'm dealing with this now in Carson. Be sure to keep the old stuff to put it back together before taking it in for any kind of warranty service!

Oiling? Do you mean re-oiling the filter after cleaning?