if i took of the airbox lid off of my 2003 400ex it would add power right? what kinda power would it add? torque or top speed? also do i just unclip it and leave the clips there? i just put the lid somewhere else and then just put the seat back on?

 

wont do much of anything except maybe make your engine bog. Add a slip on, rejet, a new K&N filter, then remove the lid. They all compliment each other. Just one change wont do much by itself.

 

coming out of a corner you may have a tad bit more torque given you rejet. if you don't you are just running the risk of hurting the motor from a lean ratio. don't expect more top speed.

 

i have heard that u will actually lose power because the air will slow down. but if u leave it on it will force the air to rush through (making more power then slow air). im not sure if this is true and no i dont run a lid and it seems to have more power without (rejet) but i also have a more high flowing exhaust pipe and a high flow filter.

 

yeah, i have tested with this before. from physics, the more volume means less velocity. the lower volume gives greater velocity. however, i really could never tell a difference in power.