Ok, it's like this. The T'bike pipes are designed for the ideal intake/output conditions on a stock 790cc BA/SM/Bonnie/T100. But...this is measured strictly by hp ahnd torque. You actually get the MOSYT hp and torque from a leaner motor than a rich one. So, too lean? Don't know for sure. Maybe someone with a stock setup can pull their plugs and tell us what they look like. Or even a G/A analysis would be even better.
Now, if you open the air up, you will need to balance the flow by flowing the gas more, larger main jets. This is not to say it is guaranteed to improve the performance, in fact T'Bike says their setup is perfect and any changes may actually decrease the performance. However, my past dyno runs and seat of the pants tells me otherwise.
What's that mean? Ok, if you get, for example, a 28% increase in hp and torque by bolting them on with stock setup this is the baseline. Then, if you remove the airbox and rejet accordingly to get the most effeecient fuel burn, you may experience another 10% increase due to more gas/air burning faster = more faster down the road.
Make any sense to ya? PapaDean is a far wiser man when it comes to carb operation so maybe he can chime in here too. I just now that my Thunderbike pipes haul some serious butt and when I went to bigger jets and such it hauled even more butt faster. Then the big bore, holy cc's it hauls large butts up hills even faster now.
Have you read this
Article on tuning exhaust systems ? It's a good reference and explains the relationship between the effeciency of motors with exhaust systems and how they are properly tuned using valve timopng, exhaust length and header dimensions. All of this is how T'Pipe builds their pipes. In theory, you have room for improvement as the valve timing and exhaust physical attributes are constant in the formulas.
