About same main jets front and rear when using CPR (or other similar concepts),
Originally Posted by blublapp
An austrian tuner tested this out on the dyno. It's necessary because of the construction form of the original airbox in which the rear cylinder gets more air, so more fuel is needed too. He sells open airboxes too and gives out this information. My setup with an ITG filter (same as CPR) is 155/155 mains at present.
This is interesting stuff if correct and perhaps there are other inmates with skills to approve/disapprove on this.
Actually, I have an oval K&N (similar concept with respect to air flows) with 175/180 on the SDR motor since 35000 kms. Exactly same nice light brown color on both plugs.