The stock Mazda transmission was designed for an engine with a much greater range in RPM's. I believe the redline was at 7,000rpm which makes for a >5,000 rpm range figuring idle at 1,000rpm and usefulness starting at 2,000rpm. The S&S idles at 1,000rpm becomes almost useful at 2,000rpm but the real torque as well as smoothness starts at 3,000rpm and tops out at 5,000rpm! That makes for a >2,000rpm sweep which is not a sweep. It's too short.
I'd like to have an 8-speed to help fill in those holes then you'd have useful power all the way up the speedometer!
