| 45mm will be just fine if it's the noise and a small performance gain you need. If you plan on working the motor a bit more, then go for a 50mm half system.
The 45's will be the cheapest option to.
A chip from JHP is as good as any and not too expensive at around £35.
Once it's all fitted up, get it set up properly to make sure everything is just right. The chips are not a simple plug'n'play............ |