12-06-2014, 01:21 PM
Well, with 198lb.ft I'd say that's actually a good result...
Does your car do 5420RPM though whilst under heavy load? I'm going to say it won't do that RPM with load on the engine and wouldn't make that much power up there, if anything your power figure will be slightly up from actuality.
You need to understand that the torque is what they're reading - the measured torque IS accurate unless their drivetrain loss equation is wrong... Which it usually is... Just take the ATW figure and add about 17% on - their drivetrain calculation is about 19%, so again, your torque figure is actually up...
If I do a quick bit of mathematics to give you an ATW figure - if we take your 19.11% drivetrain and rotating mass loss figure - I'm going for the highest percentage I can get to give you the biggest results (
) - I'm also going to use the uncorrected values because ISO/DIN barometric correction IMHO is bullshit, especially on turbo engines.
198.7 (Lbf.Ft) - 37.95 (drivetrain loss max) = 160.7 Lbf.Ft ATW (peak)
They reckoned on your power ATW being 126.5HP.
That's starting to sound quite like it, take the Torque produced at peak power which to me looks about 174Lbf.Ft ATF
So 174Lbf.Ft ATF - minus our 19.11% drivetrain loss equals 140.75 Lbf.Ft produced at peak POWER.
Peak power was made @ 4455RPM (we're going to have to assume this figure, sounds a little high to me)
So calculation for power is (Torque(Lbf.Ft) / RPM) * 5252 = (140.75 / 4455) * 5252 = 165.93HP ATW.
So even if your drivetrain loss is slightly more than originally thought... If you don't know what RPM it was done from, you simply can't tell - this is why chassis dynos are such crap!
For the record - my dyno results I corrected with 15% transmission losses - that's the standard for FWD cars, it's near IMPOSSIBLE to measure drivetrain loses, you can estimate the static losses, but not dynamic... If you want to compare your results IMHO just correct at 15% and then they're comparable - that means that the power your car puts to the road is measured in the same way as my car... Therefore your results are comparable - if I go for a 19% transmission loss, I'm making like 190hp!
Does your car do 5420RPM though whilst under heavy load? I'm going to say it won't do that RPM with load on the engine and wouldn't make that much power up there, if anything your power figure will be slightly up from actuality.
You need to understand that the torque is what they're reading - the measured torque IS accurate unless their drivetrain loss equation is wrong... Which it usually is... Just take the ATW figure and add about 17% on - their drivetrain calculation is about 19%, so again, your torque figure is actually up...
If I do a quick bit of mathematics to give you an ATW figure - if we take your 19.11% drivetrain and rotating mass loss figure - I'm going for the highest percentage I can get to give you the biggest results (
) - I'm also going to use the uncorrected values because ISO/DIN barometric correction IMHO is bullshit, especially on turbo engines.198.7 (Lbf.Ft) - 37.95 (drivetrain loss max) = 160.7 Lbf.Ft ATW (peak)
They reckoned on your power ATW being 126.5HP.
That's starting to sound quite like it, take the Torque produced at peak power which to me looks about 174Lbf.Ft ATF
So 174Lbf.Ft ATF - minus our 19.11% drivetrain loss equals 140.75 Lbf.Ft produced at peak POWER.
Peak power was made @ 4455RPM (we're going to have to assume this figure, sounds a little high to me)
So calculation for power is (Torque(Lbf.Ft) / RPM) * 5252 = (140.75 / 4455) * 5252 = 165.93HP ATW.
So even if your drivetrain loss is slightly more than originally thought... If you don't know what RPM it was done from, you simply can't tell - this is why chassis dynos are such crap!
For the record - my dyno results I corrected with 15% transmission losses - that's the standard for FWD cars, it's near IMPOSSIBLE to measure drivetrain loses, you can estimate the static losses, but not dynamic... If you want to compare your results IMHO just correct at 15% and then they're comparable - that means that the power your car puts to the road is measured in the same way as my car... Therefore your results are comparable - if I go for a 19% transmission loss, I'm making like 190hp!
