Carried out this mod on mine this morning.
Went out and there was no negative effect, whether there's a gain, i'm not sure but still pulled very strongly 8)
I have an idea of getting more cold air into the intake pipe which involves running a piece of flexible aluminium pipe down to a cooler part of the engine bay (Comptech icebox style)
Then conecting into the bottom of the intake pipe by cutting a hole in the bottom, thus keeping the original open end aswell.
Do you think this would have the effect i'm after?