Originally Posted by DiavelM3
Aren't these intakes (Including the OEM intake) designed to move air into the intake system more efficiently while the car is in motion (Not a RAM air system but similar)?
Also, at what point would you do a tune (ECU tune like a Dinan)? After an intake, pulley, exhaust mod? Or would you do a tune after doing just an intake mod like this?
The stock airbox is very efficient, I have a hard time seeing any improvements being made. The plastic construction goes a long way to prevent thermal conductivity (ie: heatsoak). However, the connecting elements (filter, charge-pipes) are where the primary gains are being seen. On the software end, you should be on 231E.
Pulleys are different - they free
up power rather than gain (less parasitic drag on engine). The end result is the same. you really can't go wrong.
On the exhaust side, catalytic converters rob HP on the M3 - as they are very restrictive. Switching to HFC or removing them altogether will show sizable gains and possible shave some unneeded weight.