15-03-2012, 12:25 AM
There will be some controversy over what I say next:
Notice on the graph, it says "Driveline Efficiency 95%" - that means your driveline loses 5% power... Which isn't right for an FWD car, mine's identical - i.e. they didn't do a coast down test on the rollers.
Which means if you do the maths...
141hp = 105% of the WHP figure...
1% = 141HP/105%
1% = 1.342 * 100% = Wheel Figure = 134.2HP
10% of 134.2 = 13.42
5% of 134.2 = 6.71
Power Loss @ 15% = 20.13
Wheel Figure + 15% Losses = Flywheel = 154.33HP
Do the same with the torque figure of 251lb.ft which brings it to 273.7lb.ft torque...
Which I'd say is MUCH closer to the actual figures...
Generally it's accepted a FWD car will lose about 15%, RWD about 20% and AWD/4WD about 20-25% depending on how it's setup... At least, Dyno Dynamics "Shootout" rollers use these corrections...
Notice on the graph, it says "Driveline Efficiency 95%" - that means your driveline loses 5% power... Which isn't right for an FWD car, mine's identical - i.e. they didn't do a coast down test on the rollers.
Which means if you do the maths...
141hp = 105% of the WHP figure...
1% = 141HP/105%
1% = 1.342 * 100% = Wheel Figure = 134.2HP
10% of 134.2 = 13.42
5% of 134.2 = 6.71
Power Loss @ 15% = 20.13
Wheel Figure + 15% Losses = Flywheel = 154.33HP
Do the same with the torque figure of 251lb.ft which brings it to 273.7lb.ft torque...
Which I'd say is MUCH closer to the actual figures...
Generally it's accepted a FWD car will lose about 15%, RWD about 20% and AWD/4WD about 20-25% depending on how it's setup... At least, Dyno Dynamics "Shootout" rollers use these corrections...
