Novel VAG-COM use - Road Dyno

[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


5th gear


Comments welcome, and post your graphs

Crunchster

[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...

[Crunchster]

Here's the boost plots, MRP (bar) vs rpm

[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

[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.