HP 1.8 TS

[richardholdener]

Drivetrain losses are actually not a percentage nor are they a truly fixed value. Lets take a wild example here of a 1000-hp turbo V8. If the dirvetrain loss in a Camaro or Mustang is 15% at the 400-hp level, it will not be the same 15% at the 1000-hp level. The drivetrain losses will only increase slightly with increased engine output. Percentages are usefule and fairly accurate with stock vehicles since the OEMs have a direct correlation between the hp tested (under their specific conditions) on the engine dyno and on a chassis dyno. Once you modify the motor, the percentage starts changing. Minor mods (10-15 hp) will have little effect on the accuracy of the percentage but the greater the power output, the more the strict percentage will be off. Best to use actual dyno numbers and gains registered there on. BTW-The stock 1.8L in the 08 Scion Xd put out 119-120 wheel hp on my Dynojet.

Originally Posted by thebarber

the standard #'s i use are 13% and 25% for manual/auto drivetrain loses from the crank to the wheels.....usually fairly accurate....