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Novel VAG-COM use - Road Dyno

Posted: Sun May 27, 2007 7:31 pm
by Crunchster
Was doing some logging on my brothers MRC Stage 1 tuned B5 RS4 yesterday when found a VAG-COM block (120 IIRC) that records "engine torque (actual)".

Now, I'm a bit dubious as to how this is measured, but I took the logs, calculated torque in lbft (Nm*0.737562), then converted to bhp (torque in lbft*rpm/5252), and plotted it on a graph. Here are the results:

3rd gear
Image

5th gear
Image

Comments welcome, and post your graphs :D

Crunchster

RE: Novel VAG-COM use - Road Dyno

Posted: Sun May 27, 2007 7:34 pm
by Crunchster
PS This was with 1.5 bar peak, 1.35 held tailing to 1.2 bar at peak power. Charge temps were in the 50-60 degrees C range at the end of each pull (particularly in 5th) so not a bad result I reckon... :)

RE: Novel VAG-COM use - Road Dyno

Posted: Sun May 27, 2007 7:50 pm
by Crunchster
Here's the boost plots, MRP (bar) vs rpm

Image

RE: Novel VAG-COM use - Road Dyno

Posted: Mon May 28, 2007 12:06 am
by shineydave
looks good to me, maybe Uwe would be good enough to pass comment on how block 120 is created so we know how valid the data is

RE: Novel VAG-COM use - Road Dyno

Posted: Mon May 28, 2007 11:21 pm
by Crunchster
I have no idea how it is calculated, but suspect it may be derived from mass air flow. The logging parameter is "engine torque (actual)", then the rest of the calculations to get from Nm are pretty straight forward, as detailed above.