[Tommy]

My experience also says black side pipes are faster. That's because my muffled street pipes are shiny ceramic, but my straight-through track pipes are BBQ grill black. I think the forward thrust of all that noise exiting out the straight pipes at full throttle must be good for at least two or three MPH. The only time they seemed slower was when I had to back off the throttle passing the microphone used to identify cars exceeding the track's noise limit.