If I go from V&H Monster Ovals to V&H Pro Pipe would I have to retune my bike? I have a TTS Mastertuner the bike was dynoed tuned with the Monster Ovals.

 

Anything that has an effect on the air flow would require or should require the retune. That is what I have been told. Might ask V&H how much difference there is in the restriction of the two mufflers. Might not be big enough to make a difference

 

Yes you do. The MO's have a lot more restriction than the pro pipe, it would run too lean if you free up the exhaust back pressure. I have the MO's and am thinking of going to Super trapp 2:1, my tuner said it wont take much to tune because I have a base map from the Crushers before the MO's.