Power and torque graphs from VAGCOM

[EspenW]

On the newer cars, all sorts of cool things can be logged with VAGCOM: AFR, EGT, MAF flow,boost,misfires, timing pull, etc in addition to the things we can do on the older cars like IAT and timing.

One very cool feature is block 120. It displays a value for the torque produced at the engine. It is calculated from various parameters like airflow, temperature, ignition angle, etc, and it seems to be very accurate for a stock ECU. The ECU supposedly uses the information for the traction control management, etc.

I tested on a B6 A4 1.8TQ. It is rated at 163ps @5700rpm and 225nm from 1950 to 4700rpm.

I did a 3rd gear pull from 1500rpm to redline and made charts. As long as you have torque and rpm, power is only an equation away.
I got 160hp at 5800rpm and a maximum of 250nm. These engines are underrated from the factory, so the higher torque number makes sense.

Here are the charts for power and torque. I also logged horsepower at the wheels with my MR Dyno meter and got a maximum of 136hp at the wheels. The shape of the "engine hp" and whp graphs track each other nicely.

[S2central.net]

That'll be an ME7 trick - torque demand based system - bit more exotic than our old M2.x.x but yes it is a nice feature !

[EspenW]

Yep, the ME7 is pretty awesome.
Found a way to get MAF values from the old school Motronics?

[Rusty]

Got to be a way of measuring voltage off it and logging it... just need the conversion graph or equation then.

[S2central.net]

This gets us right back to my eternal search for a flow graph from our wee MAF... Bosch publish them nowadays for voltage vs grams of air, but I have never sourced a datasheet for our MAF. A man with a flowbench and a voltmeter is all we need to collect some data as we can convert CFM from the bench into air mass. Then it will be easy to plot the MAF and confirm a good one vs a bad one. I did some quick calcs before about what sort of range was required from the bench for our MAF - another way to do it is test in parallel with a reference MAF (e.g Bosch HFM with its official data) - that gives another checkpoint for the CFM to mass conversion.

[EspenW]

Could MAF data in any way be connected to the load data that we can log?

[GazzaG60]

you may laugh and tell me where to go.

can you not get a hoover or somthing you know the cfm of.

attach to said maf and flow it and measure signals.

or maybe engineer the other way and use an SMT6 to do map instead of maf v emulated and reverse it back.

or just buy vems.

gotta agree me7 is a good system.

[GazzaG60]

id ecpect i can get cfm of certain vacs too. after all we make them and design them along with the filters for hepa or exhaust where cfm is the daddy figure

[HPmuirt]

Most modern PC fans are fairly accurately spec'ed regarding cfm if that helps and are 12V too.

Cheers n

Si

[S2central.net]

PMSL at PC fans... Try and visualise the amount of air being inhaled by 2.2l engine every minute and imagine what sort of PC or Hoover can ingest. A proper flow bench is required.

[S2central.net]

Could MAF data in any way be connected to the load data that we can log?

It is related somehow but I have never cracked that little mystery. Once we have the MAF characterised then it would be possible to look for some sort of correlation from datalogging.

[quattro84]

Some bosch (motorsport) MAF's are supplied with full caracteristics., i don't have any but they float around on the interwebz.

We use open Bosch ECU's in the development stage of new engine, and the torque predictions are quite accurate because the equations are adjusted during the calibration in the development stages.

[EspenW]

It shall be interesting to see if the torque values will be valid after I reflash the ECU with the BSR software (had it running stock map for the MOT). A lot of aftermarket maps will make the block 120 measurements invalid.