[Yozh]

After TDIwyse has posted his data logs with the new turbos, as he usually does with some great data. It made me think that may be we should have a thread dedicated to logs. We have TestO, Torque and Carly at our disposal. TestO provides the best logs, but others have some ability to gather data as well. It would be great to show performance, but also be nice to be able to compare parameters when trying to troubleshoot. For example, it would be nice to see turbo switchover behavior, or how requested vs. actual boost looks and compares to another car. Looking at the parameters table, there are hundreds, and some are interesting but rarely reported. Of course there is lots on injection, glow plugs, etc. There is one on intercooler efficiency - be nice to use that one for intercooler comparisons. Anyway, wonder if this is something that can be supported by the community.

Just for fun, this is a snippet of my drive to work this am...

[TDIwyse]

Originally Posted by Yozh

...It made me think that may be we should have a thread dedicated to logs...

Love it.

I had started something like this back in 2/2012 on TheFest site (but haven't been active over there for a long time): http://www.bimmerfest.com/forums/sho...d.php?t=598240

There's a lot of good data and behaviors captured for the car when it still had all the OEM systems in place. Things like DPF regens, EGR/Throttle behaviors, injection event behaviors, etc.

[TDIwyse]

Originally Posted by Yozh

... It would be great to show performance, but also be nice to be able to compare parameters when trying to troubleshoot. For example, it would be nice to see turbo switchover behavior, or how requested vs. actual boost looks and compares to another car. ...

I found my old log from this post: http://www.e90post.com/forums/showth...tchover&page=5

It had, what I think, might be the turbine switchover command. If it's not the correct one someone please let me know. It is at least tightly correlated with the precise rpm where the LP turbo comes online and the EMP behavior radically changes on my vehicle.

STAT_TrbCh_r_WERT

[Yozh]

Originally Posted by TDIwyse

It had, what I think, might be the turbine switchover command. If it's not the correct one someone please let me know. It is at least tightly correlated with the precise rpm where the LP turbo comes online and the EMP behavior radically changes on my vehicle.

STAT_TrbCh_r_WERT

STAT_TrbCh_r_WERT is a boost pressure plate target duty ratio.

In the graph I had posted in the first post in light blue is a similar parameter: TrbCh rPs which is a STAT_LADEDRUCKSTELLER_ANSTEUERUNG_WERT, it is Boost pressure plate output duty.

There are quite a few boost pressure plate parameters, I'm sure some of them are doubles and some of them are not applicable, but would be nice to compare some of them and find the most useful.

I find mine behaves most likely correct, but not exactly what BMW describes that it's all small turbo under 1500rpm. I think it depends on boost request, where in normal driving it may start bleeding EMP to LP turbo as early as 1000 rpm, then if more boost is required, it will start closing back up again to give more to HP and then in higher rpm where more boost is required, it will open up for more and more LP feed.

[TDIwyse]

Originally Posted by Yozh

STAT_TrbCh_r_WERT is a boost pressure plate target duty ratio.
...

Thanks.

Do you know which parameter is the control for the turbine switchover valve?

[kydiesel35]

I don't have testO at the moment... What logs do you want from torque? May take a couple days but I should be able to find time.

[grizzjr1]

I'd be glad to chip in on some logs when I get my car back together. I'm honestly pretty surprised we don't have a good size database of logs already. I have a few I can post, but they are from trying to figure out my turbo issue. AFR won't read, which is odd. Any specific parameters you guys want logged? And how do you guys go about graphing them so nicely? I put them in an Excel sheet. I haven't been able to use TestO yet, but will when my cable is here tomorrow

EDIT: Nevermind... I wasn't even thinking about Excels ability to insert graphs. Derp. I am looking at the last log I made before I tore apart the car. There is something fishy going on, it appears as though suddenly my exhaust manifold pressure sensor dies, then the exhaust temp a millisecond later, and 2 seconds later the Pre DOC egt dies... This continues for 4 more seconds then everything comes back online like nothing happened. Very odd! I attached a log and a picture of the graph from that time. 27:45.1 to 27:52.4. Have you guys seen sensors die and just come back online? Or is this an issue with torque logging?

Light gray that jumps is ex temp post DOC
Orange is exhaust MAP
Yellow is pre DPF temps

[pheno]

Great idea! I can also provide some logs but I only have this "partial" engine as I like to call it after owned E34 540 v8 for 9 years :-) It's an N47 DDE7.1 4 cyl. 2.0 liters. It seems DDE7.1 does not have STAT_TrbCh_r_WERT :/

Yozh: Love the resolution of your log. Seems TestO is working quite nicely for you. 'Custom jobs' is the key for getting the best resolution (multiple data points in one reply packet from DDE).

If you have created some good 'custom jobs' for TestO I'd be happy to add them in the next release of TestO. I was thinking it would be easy for 335d owners to pick them.. and then we could see exactly the same data points in each log also. Thanks.

[Yozh]

Originally Posted by TDIwyse

Thanks.

Do you know which parameter is the control for the turbine switchover valve?

Here is what I was able to find so far:

-STAT_LADEDRUCKSTELLER_ANSTEUERUNG_WERT = Boost pressure plate - output duty;
-STAT_TrbCh_r_WERT = Boost pressure plate - target duty ratio.

On my car these two are exactly the same and simulate what the pressure converter for the turbine switchover is being requested of.

The following ones are dead and show no value or show a constant value and do not change. To me, these make sense as there is no positional feedback from the turbine switchover like there is for EGR or the swirl flaps (both, on US cars):

-STAT_TrbCh_rAct_WERT = Boost pressure plate - corrected actual position;
-STAT_TrbCh_rRaw_WERT = Boost pressure plate - actual position raw value;
-STAT_TrbCh_rSens_WERT = Boost pressure plate - actual position of sensor characteristic.

For the compressor bypass, I have found the following:

-STAT_CByVlv_st_WERT = High pressure compressor bypass valve - Status.
This one shows a zero value when closed and a "1" when open. Conditions are over 3000 rpm and higher boost.

-STAT_TrbChLP_rPs_WERT = Low-pressure supercharging pressure plate - output duty.
This one is at "95" when closed and at "5" when open. Same conditions as above.

-STAT_TrbChLP_r_WERT = Low-pressure supercharging pressure plate - target duty ratio.
Same as previous, but at "94.995" when closed and at "5.00487" when open.

I have not looked for the wastegate yet.

[Yozh]

Originally Posted by grizzjr1

Or is this an issue with torque logging?

I have noticed Torque having blips sometimes. Can look at my logs if it was one sensor or all of them. But if you are going to go TestO, then do not look back. TestO would be a much better platform to confirm if one of your sensors is dropping out or you have just a communication issue. Hope we can figure out in this thread how to diagnose various issues, along with a "problem" of too much power such as in TDIwyse's case.

Originally Posted by pheno

It's an N47 DDE7.1 4 cyl. 2.0 liters. It seems DDE7.1 does not have STAT_TrbCh_r_WERT :/

Is it a single or bi-turbo version of N47 that you have. If sinlge, then that parameter should be dead. If bi-turbo, then try STAT_LADEDRUCKSTELLER_ANSTEUERUNG_WERT.

Originally Posted by pheno

Yozh: Love the resolution of your log. Seems TestO is working quite nicely for you. 'Custom jobs' is the key for getting the best resolution (multiple data points in one reply packet from DDE).

Thanks Pheno. I have taken your advise on custom jobs to heart and thank you again for such a great tool that you have created for us.

Originally Posted by pheno

If you have created some good 'custom jobs' for TestO I'd be happy to add them in the next release of TestO. I was thinking it would be easy for 335d owners to pick them.. and then we could see exactly the same data points in each log also. Thanks.

Hope to do so. And with more testing would come up with some useful diagnostic ones. Still playing with it and enjoying it more and more.

[pheno]

Would it be possible to calculate torque/HP from the parameters that can be requested from DDE or even a close estimate ?

There's possibility in TestO to create a formula based on data point values and add that result for logging and viewing. Easiest example would be to convert km/h into mph.

I'm not a diesel guru but I'd guess there must be some formula how to do that. I guess calculating torque must be based on injected amount, RPM, Air mass, etc. There seems to be a parameter to get acceleration also.

[TDIwyse]

Originally Posted by pheno

Would it be possible to calculate torque/HP from the parameters that can be requested from DDE or even a close estimate ?

There's possibility in TestO to create a formula based on data point values and add that result for logging and viewing. Easiest example would be to convert km/h into mph.

I'm not a diesel guru but I'd guess there must be some formula how to do that. I guess calculating torque must be based on injected amount, RPM, Air mass, etc. There seems to be a parameter to get acceleration also.

Theoretically, this should be doable. Force=Mass*Acceleration ... this would be similar to how accelerometer based devices calculate it (G-Tech, PerfExpert, etc.).

You'd need to know the mass of the car. TestO could get acceleration from the delta speed/delta time (change in speed vs change in sample time step ... this might need to be averaged over multiple samples if there's variation). If you know the acceleration and mass, you could get force. From force, and knowing the rpm, you should be able to get power.

What would be neat, is if you could also account from wind drag like PerfExpert does. You need the Fa and Cd of the vehicle (these are published, so it's knowable), and then you can account for wind drag forces from velocity and back out those losses.

The car also knows the ambient temp and pressure (although it seems to have a 10mBar resolution, which isn't great), so you could apply correction factors to the measured results to account for ambient variations (again, similar to PerfExpert).

Edit: You'd probably also need to know the gear ratio, differential ratio and tire diameters...

[TDIwyse]

Originally Posted by grizzjr1

...I am looking at the last log I made before I tore apart the car. There is something fishy going on, it appears as though suddenly my exhaust manifold pressure sensor dies, then the exhaust temp a millisecond later, and 2 seconds later the Pre DOC egt dies... This continues for 4 more seconds then everything comes back online like nothing happened. Very odd! I attached a log and a picture of the graph from that time. 27:45.1 to 27:52.4. Have you guys seen sensors die and just come back online? Or is this an issue with torque logging?

Light gray that jumps is ex temp post DOC
Orange is exhaust MAP
Yellow is pre DPF temps

I use Torque a lot, and haven't seen anything like that. Perhaps your obd dongle is loosing sync/connection with the phone? But I'd expect everything to fall out then ... Moving to TestO like Yozh said, which provides a hard connection to the measuring device, would eliminate one possibility.

But intermittent sensor behavior like that can sometimes be an electrical issue. Is it possible the connectors to those sensors are not fully engaged and locked in place? Or did the wire connectors get damaged? Or is the wire loom and connection going back to the DDE having any issues?

Chasing electrical issues can be a major pain ...

[pheno]

Originally Posted by Yozh

I have noticed Torque having blips sometimes. Can look at my logs if it was one sensor or all of them. But if you are going to go TestO, then do not look back. TestO would be a much better platform to confirm if one of your sensors is dropping out or you have just a communication issue. Hope we can figure out in this thread how to diagnose various issues, along with a "problem" of too much power such as in TDIwyse's case.


Is it a single or bi-turbo version of N47 that you have. If sinlge, then that parameter should be dead. If bi-turbo, then try STAT_LADEDRUCKSTELLER_ANSTEUERUNG_WERT.

Thanks Pheno. I have taken your advise on custom jobs to heart and thank you again for such a great tool that you have created for us.

Hope to do so. And with more testing would come up with some useful diagnostic ones. Still playing with it and enjoying it more and more.

Thanks !

I got only single turbo year model 2008. STAT_LADEDRUCKSTELLER_ANSTEUERUNG_WERT yes that sounds familiar. So it's the output duty cycle for "boost controller" ?

[DWR]

Originally Posted by TDIwyse

Theoretically, this should be doable. Force=Mass*Acceleration ... this would be similar to how accelerometer based devices calculate it (G-Tech, PerfExpert, etc.).

You'd need to know the mass of the car. TestO could get acceleration from the delta speed/delta time (change in speed vs change in sample time step ... this might need to be averaged over multiple samples if there's variation). If you know the acceleration and mass, you could get force. From force, and knowing the rpm, you should be able to get power.

Weight and Acceleration derived from speed differential with respect to time is all that is required. However, you can't use the OBDII speed PID because it does not have sufficient resolution. Wheel speed sensor data is better, and that is why it is used in various control strategies, ie:ABS.

Originally Posted by TDIwyse

What would be neat, is if you could also account from wind drag like PerfExpert does. You need the Fa and Cd of the vehicle (these are published, so it's knowable), and then you can account for wind drag forces from velocity and back out those losses ..

I think you and I have both fit the curve for wind resistance, and found close agreement. I don't have that with me right now. May be you could publish the function for wind drag as a function of velocity. Wind Drag = CV^2

BTW, you can get pretty close to Crank HP using coastdown deceleration from high speed (100+ mph). The HP loss measured will include wind, and drivetrain losses. It is not perfect because transmission losses in neutral are not the same as in gear, but it is pretty close in an automatic.

[TDIwyse]

Originally Posted by DWR

...
I think you and I have both fit the curve for wind resistance, and found close agreement. I don't have that with me right now. May be you could publish the function for wind drag as a function of velocity. Wind Drag = CV^2

BTW, you can get pretty close to Crank HP using coastdown deceleration from high speed (100+ mph). The HP loss measured will include wind, and drivetrain losses. It is not perfect because transmission losses in neutral are not the same as in gear, but it is pretty close in an automatic.

I pulled up my old spreadsheet and tried to show the calculations I had used. Please check my equation for wind drag power. Force goes as v^2, but I'm pretty sure power goes as v^3.

It's been a long time since I've looked at this, so I'm not sure of the details on some of these values/equations.

I see I was trying to correct for wind effects (for example, a negative "wind" parameter acted like a tail wind and reduced "wind adjusted speed", and that was what I was using to calculate the wind drag power).

And I used an air density calculation within the wind drag power equation, but I don't recall how/where I derived that.

Question on the coast down method. I had read that this approach isn't very accurate due to very different loads on the components during heavy accelerating vs lightly loaded coasting, and most helical cut differential gears will have different losses when "forward" loaded versus "reverse"? I haven't done significant research into this, or done my own measurements, so I have no data to use to compare.

Edit: This is one of the things I had read about the difficulty of finding the actual drivetrain loss during full power accelerating: http://www.superstreetonline.com/how...in-power-loss/

[DWR]

Originally Posted by TDIwyse

I pulled up my old spreadsheet and tried to show the calculations I had used. Please check my equation for wind drag power. Force goes as v^2, but I'm pretty sure power goes as v^3.
Question on the coast down method. I had read that this approach isn't very accurate due to very different loads on the components during heavy accelerating vs lightly loaded coasting, and most helical cut differential gears will have different losses when "forward" loaded versus "reverse"? I haven't done significant research into this, or done my own measurements, so I have no data to use to compare.

We are on the same page. Wind drag is a force. Wind drag power I guess is your term for drag times velocity, cool.

Of course, the loss is related to the power. That is how it is usually referenced, as a percentage. ZF6HP transmission accounts for 8% loss according to ZF. We have the rear gear ratio, so we can back into force. We can calculate the wind drag, as you have shown above. Sorry if I was a little casual with my post. It does involve a multi term equation. As far as thoughts about friction being different in one direction than the other, it is probably true. I just don't think a 5-10% error on a 5% term is that big of a deal.

[Persian Whisperjet]

Originally Posted by TDIwyse

This is one of the things I had read about the difficulty of finding the actual drivetrain loss during full power accelerating: http://www.superstreetonline.com/how...in-power-loss/

Great piece!

[DWR]

I think if you are fairly new to the automotive scene that article is informative. I'm not sure who reading this forum thought that crank horsepower could be measured on a chassis dyno. Rotational inertia is certainly a bigger piece of the accelerated mass than most are aware of, but to call it a loss is a little misdirected. Or should we also account for the rotational inertia of the engine?

[pheno]

Interesting discussion about how to calculate Nm and HP! I believe I can incorporate features TDIWyse mentioned in TestO but let's proceed step by step and see how far we can go. It would be nice to have these calculated values. Sort of a road dyno. I remember we had some discussion about this DWR or maybe not :-) ?


I just logged an interesting parameter: vehicle acceleration STAT_FAHRZEUGBESCHLIEGUNG among others. It was very slippery so I didn't get any good pull. Anyway that value seems to update fast or let's say as fast as the other values. If this proves to be accurate enough I believe we have the most important variable solved.

I also found parameter that's translated something like: torque from clutch. STAT_ActMod_trqClth_WERT. Also updates fast and in real time. It must be a calculated value by DDE based on the resolution and not any fixed value taken from some table. Might be a good reference to compare with other values.

[grizzjr1]

Originally Posted by Yozh

I have noticed Torque having blips sometimes. Can look at my logs if it was one sensor or all of them. But if you are going to go TestO, then do not look back. TestO would be a much better platform to confirm if one of your sensors is dropping out or you have just a communication issue. Hope we can figure out in this thread how to diagnose various issues, along with a "problem" of too much power such as in TDIwyse's case.

Originally Posted by TDIwyse

I use Torque a lot, and haven't seen anything like that. Perhaps your obd dongle is loosing sync/connection with the phone? But I'd expect everything to fall out then ... Moving to TestO like Yozh said, which provides a hard connection to the measuring device, would eliminate one possibility.

But intermittent sensor behavior like that can sometimes be an electrical issue. Is it possible the connectors to those sensors are not fully engaged and locked in place? Or did the wire connectors get damaged? Or is the wire loom and connection going back to the DDE having any issues?

Chasing electrical issues can be a major pain ...

I am going to go with my dongle losing connection, after those first few logs I was worried! After doing another 10 or so, I have noticed when it begins to disconnect. Drops a few sensors then holds the others static until it is unplugged and reconnected. Odd.

I went over all of the sensor connections since I have spent so much time in that area while I was trying to figure out turbo issues. They seem to be good. I haven't had a single surge issue since I have disconnected my throttle plate, so I guess that it was sticking! I haven't seen that issue yet around the forums, I am going to gut the plate and disconnect it to keep the computer happy. Or I suppose I can just throw my race pipe on. Still doesn't explain why I can hit 33 psi with just JBD at 100 percent, but I'm not certain whats up there.

I ordered a DCAN cable and it will be here Monday. I would be happy to log (45 minute drive to work) and look around for other fun stuff. For now I'm just enjoying the car functioning properly with the R90 installed and meth working again. Transmission tune should be coming out soon as well, that's exciting!

Thanks again for all of your guys' help to the community.

[Yozh]

Originally Posted by pheno

I just logged an interesting parameter: vehicle acceleration STAT_FAHRZEUGBESCHLIEGUNG among others.

I wonder how this one compares to STAT_MoFVSS_a_WERT = Vehcle acceleration for function monitoring.

Originally Posted by pheno

I also found parameter that's translated something like: torque from clutch. STAT_ActMod_trqClth_WERT. Also updates fast and in real time. It must be a calculated value by DDE based on the resolution and not any fixed value taken from some table. Might be a good reference to compare with other values.

I have monitored the one called STAT_MOTORMOMENT_AKTUELL_WERT = Current Engine Torque, and have pegged it against the one called STAT_VERHAELTNIS_AKTUELLES_MOMENT_MAXIMALMOMENT_WE RT = Ratio of Actual Torque to Maximum Torque.

It's interesting that my max torque for the MOTORMOMENT AKTUELL does not go past 590Nm (but then I was not pushing it either). Here is a graph where blue is an actual torque and orange is the ratio. For whatever reason TestO did not graph the ratio for me. At 590Nm the ration is 100%, so that value is somehow stored in the system as max and thus not a measured value.



Be interesting to see if STAT_ActMod_trqClth_WERT is the same or follows the STAT MOTORMOMENT AKTUELL WERT.