That is impressive and I really appreciate you posting before and after results and operating with RWHP. That is the most credible way to use dynoresults IMHO.
As tested this car has a 122hp (!!!) gain at the rear wheels
. It's common to use a 15-18% drivetrain loss factor, meaning that the stock car had around 620HP at the flywheel (which also is in line with what others have tested).
The Manhart MH5S then has around 740-760HP
at the crank!!!!!
(645x1,15 or 1,18 = 740-760)
Or if the drivetrain loss number of 15-18% is calculated from the crank HP, the results would be:
645/0,85 = 758HP
(with 15% drivetrain loss - 758x0,85= 645RWHP)
645/0,82 = 786HP
(with 18% drivetrain loss - 786x0,82= 645RWHP)
Not sure if people normally just add drivetrain loss of 15-18% to the RWHP figure or if they actually take the RWHP figure and divide it by the "drivetrain efficiency" factor...
Either way, this car is seriously impressive