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Old 03-12-2012, 12:11 PM
TDIwyse TDIwyse is offline
Officially Welcomed to the 'Fest
Location: Midwest
Join Date: Sep 2010
Posts: 429
Mein Auto: 4 diesels

Saw some comments in another thread regarding DPF back pressure and since I had data available . . .

Here is some measured data which includes the backpressure on my d from the BT tool during full fuel acceleration runs. The March 10th one was directly after a completed DPF regen, so is likely the lowest possible back pressure condition possible regarding the DPF. The March 4th one would've been as it was getting loaded up previous to the regen.

It's neat that using the recorded rpm and "torque" data you can make a dyno plot. This could be fun I'll need to increase the recording speed of the data next time (the "dyno plot" has a shift occuring in there and time is too coarse, but it shows some good potential).

Interestingly the pressure across the DPF during full fuel isn't as bad as I would've expected. 140 hPa is ~2 psi.

Oh, and here are the reported "units" for the data I've been taken.

Time sec
Coolant temperature C
Exhaust Gas Recirculation duty cycle command %
Actual boost pressure hPa
Actual rail pressure bar
Exhaust gas pressure before particle filter hPa
Traveled distance with this oil km
Average engine speed rpm
Fuel temperature C
Engine oil temperature communicated on Low CAN C
Command time for main injection 1 usec
Command time for pre-injection 1 usec
Command time for pre-injection 2 usec
Command time for post injection 1 usec
Command time for post injection 2 usec
Traveled distance since last regeneration (16bit) km
Actual ash quantity g
Soot mass in particle filter g
Differential pressure of the particle filter hPa
Absolute pressure in particle filter hPa
Corrected pressure before particle filter hPa
Fuel quantity consumed since last succesful regeneration l
Temperature befor oxydation catalyst C
Temperature before particle filter C
Ratio between actual and maximal torque output %
Current engine torque output Nm
Desired drive torque Nm
Actual slip torque Nm
Attached Thumbnails
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2011 335d 11.8 sec 120 mph 1/4 mile NHRA certified track

2004 Ram Cummins with lots-o-mods
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