I have a K&N and I and probally going to get a K&N PowerLid and an FMF Powerbomb.. would a DynoJet Kit Stage 1&2 be enough? This is the info from there site:

Stage 1
For midly tuned machines using stock airbox with stock or aftermarket filter. May also be used with a good aftermarket exhaust system.

Stage 2
For mildly tuned machines using stock airbox lid removed, using stock or aftermarket filter. Sould also be used with a good aftermarket exhaust system.

Also, what one should I use? Thanks a lot!

P.S. This is for a 2003 400EX

 

Instructions tell you exactly which to use. Stage 1 is for lid on, stage 2 lid off/cut/holes.