that's why the calculator uses MPH, not ET. chassis setup shouldn't affect MPH too much. they'll kill your launch, which affects etc. try it next time you're at a test & tune by varying your launch. go for a hard launch, then a light launch...you're ET might vary widely, but your MPH will probably be very close.

Ryan- I'd assume then that the moroso calculator is actually calculating power to the pavement, not flywheel HP? or does it have some algorithm in it to accomodate drivetrain loss, at which case, then it looses accuracy, as a manual trans probably has a good 15-20HP efficiency gain over a 904, which has a good 15-20hp efficiency gain over a 727....