[arayz]

Alex have 356.8 engine hp

[335dM]

318whp @18% loss = 375.24 bhp

[Puerto Rican 335d]

Dixy the set of wires are BROWN and they have a SILVER tag on them you can clamp on the the torque reader ok on any of the BROWN wires

[2deerwhistlers]

Originally Posted by 335dM

318whp @18% loss = 375.24 bhp

What tune are you rocking?

[TDIwyse]

This place has a huge database of different cars and also has the advantage of not having the tire/wheel loss involved in the equation. Lots of statistical data on the measured power/torque delivered to the axles vs manufacturer claimed numbers. They have great explanations of the different types of losses involved (constant, speed and load losses). They describe why using a fixed loss or trying to measure loss with a rolling road type dyno will not be accurate. It was an interesting read.


http://rototest-research.eu/index.ph...&Menu=38&ID=11


The 335d results are located here:

http://rototest-research.eu/popup/pe...p?ChartsID=688

Compare to an M3 with manual transmission

http://rototest-research.eu/popup/pe...p?ChartsID=768

The diesel with automatic actually measured lower losses (closer to stated power/torque) than the manual transmission M3.

[arayz]

Originally Posted by 335dM

318whp 18% loss = 375.24 bhp

How much u want to bet ur wrong ?

Ill buy u a wagner ic if im wrong and u buy me one if im right ^^

[WreckerX5d]

With the 8.5% loss, like the results TDIwyse posted, the car with 318whp has 345bhp.

[Hoooper]

Originally Posted by TDIwyse

The diesel with automatic actually measured lower losses (closer to stated power/torque) than the manual transmission M3.

Those are based on manufacturer stated numbers though which are pretty often not correct, BMW certainly enjoys underrating their engines. The only way to really get it figured out in my opinion would be to run one on an engine dyno and then run it on the same dyno connected through the trans. Otherwise you're introducing a whole bunch of variable not the least of which is that dyno results are often just plain wrong.

[WreckerX5d]

Originally Posted by Hoooper

Those are based on manufacturer stated numbers though which are pretty often not correct, BMW certainly enjoys underrating their engines. The only way to really get it figured out in my opinion would be to run one on an engine dyno and then run it on the same dyno connected through the trans. Otherwise you're introducing a whole bunch of variable not the least of which is that dyno results are often just plain wrong.

That seems like too much effort for a number.

[Hoooper]

Originally Posted by Wrecker335d

That seems like too much effort for a number.

I agree, and I figure that's why you don't really ever see the values. You might be able to find some for widely used transmissions in the aftermarket like a th350, th400, t56, a700, etc. but nobody is going to take the time and expense to do it for ours. In the end it doesn't really matter for us, what you make at the flywheel doesn't mean anything unless you plan to swap it into a plane and bolt a propeller to it. Wheel power numbers are more useful.

[TDIwyse]

Originally Posted by Hoooper

Those are based on manufacturer stated numbers though which are pretty often not correct, BMW certainly enjoys underrating their engines. The only way to really get it figured out in my opinion would be to run one on an engine dyno and then run it on the same dyno connected through the trans. Otherwise you're introducing a whole bunch of variable not the least of which is that dyno results are often just plain wrong.

I agree.

They have a plot of the % variation from claimed to measured across >400 separate auto's and bunches of manufacturers. Average % "loss" from claimed performance was ~10%. But this didn't have the tires involved which add more loss (that's why the tires get hot when they're rolling ... they dissipate power).

I find the whole drivetrain % loss on dyno's to get back to crank a little like Black Magic. Why do we care about anything other than what gets put to the ground?

[Hoooper]

Originally Posted by TDIwyse

I find the whole drivetrain % loss on dyno's to get back to crank a little like Black Magic. Why do we care about anything other than what gets put to the ground?

Haha, yep absolutely. A lot of the European dyno charts show a 25% value for figured drivetrain loss and then everyone wonders why the cars compared to similar US dyno numbers don't seem to perform. Might as well not dyno and just through darts to decide what your figures are. WHP and WTQ are king in the real world, nobody should care what theoretically is put to the flywheel.