I agree the 9/15 is pretty sweet
i went from 4.5 mil cut on a 13/15 to the out of the box 9/15
definately pulled more at real low rpm, sorta had a fad in mid and i guess even on top, perhaps slightly less
this is compared to the 13/15 i ran
personally i am going back to the 13/15, especially after the motor is rebuilt. i think i'll get slippage with the 9/15
Actually Dave can't believe i'm not spinning it or the 13/15, i also told him my fat a$$ is attached to the ski too
i'm not sure if the out of the box setup can be cut back any further on mine, seemed like that was probably as far back as it can go. Dave wants the pump assy if i were to want it cut further to truly investigate it
none-the-less i had good bite with it, especially in the wash of her SXR
it's definately worth trying for sure
and i was surprised because it was a little heavier (nothing dramatic, but you can feel it in your hands for sure), but perhaps it falls inline with the heavier flywheel theory that drag racers like