I've noticed that several people at recent Evo meets I've attended have been running with the stock air box lid removed. To me, it seems like that would have two consequences: One being the induction of hotter air and the other having the possibility of water entering the system via the hood vent.

Are these consequences valid? Do the pros outweigh the cons?

Thanks in advance!

 

I popped mine off once just for a drive to lunch. I am a sucker for the awesome BOV noise (even with a stock intake system!) and loved every minute of it. I don't see how the stock filter is really sealing well in this scenario though, so I wouldn't do it long term. I mean, the lid basically applies clamping pressure to seal the filter gasket. W/out that pressure, I'd be afraid that raw air can just bypass around the sides of the filter.

Personally, I think the cons you listed *are* valid. What pros are there beside the cool sound?

 

i have no idea about the gains of having it off but if i were you id only pull it off occasionally and definately not if it is raining!

 

The same "trick" threw mine into limp mode a few years back. The ECU saw too much air under high load, freaked out and thew 1/2 of a tank of gas at it (exaggerating a bit)

I don't see how it's much different than adding an intake & cone without a tune.

Hot air is your enemy, less dense, lower cylinder pressure. More strain on the engine to make equivalent power that it would with cooler air.

Your observation about the dirt is a good one.