does a K&N air filter effect the 03 grizzly's 660 performance?
 

i just got a 03 grizzly 660 and i want to know if the K&N air filter will effect it at all?

does a K&N air filter effect the 03 grizzly's 660 performance?
 

K&N filters flow more air so it should give you better performance.

does a K&N air filter effect the 03 grizzly's 660 performance?
 

pretend you have a straw with with a little bitty hole on both ends. If you make one hole bigger, it gets a little easier to blow through, if you make both holes bigger it gets alot easier. Works the same way with pipe and filter. Might consider opening up the stock exhaust a lil or buying another one.

does a K&N air filter effect the 03 grizzly's 660 performance?
 

Probably a little better with the filter, but I wouldn't figure much. Add the pipe to it and you will notice a difference pretty clearly. The HMF did a lot for mine, though I must say its extremely loud. Much quicker though now.