[TDIwyse]

Originally Posted by Yozh

Number 6 in the below diagram. Mounts onto #1, you can see it if you take the engine cover off. Pipe #9 takes exhaust feed just below the high pressure turbo, M17 banjo bolt.
Attachment 1142165

Thanks! I hadn't noticed that before. Hmmm, now I really wish I had taken some data on that parameter as I was modifying the exhaust and moving to the EWG ... I don't suppose you would post some full fuel/rpm logs on this with your car?

[TDIwyse]

Originally Posted by Yozh

Thanks TDI. Can you confirm that in Torque settings you have left boost adjustment at "zero". Please and thank you. I wish BMWhat would have a boost parameter. Seems weird not to have one.

Yes, I'm leaving boost adjustment at "zero".

Note, if you still have EGR working the Torque boost numbers at low/mid fueling can be WAY off, as most of the intake air is from the EGR which does not flow through the MAF ... so Torque will be reading ~0 psi of boost because the MAF reading is so low due to heavy EGR utilization.

[iaknown]

Logging with wastegate open was mentioned earlier, not exactly sure what information you're after though....

[Yozh]

Originally Posted by TDIwyse

Thanks! I hadn't noticed that before. Hmmm, now I really wish I had taken some data on that parameter as I was modifying the exhaust and moving to the EWG ... I don't suppose you would post some full fuel/rpm logs on this with your car?

I would be happy to provide what I have, but I doubt I am a good reference. As you may recall I was tripping limp and code 4530 and have now eliminated the problems and double check all of the controllers. I'm also running gutted DPF with DOC so I'm going to have a bit more back pressure. Still running rich though, so I'm thinking it is either the SCR plugged by urea and soot or the tune does not like my DPF/DOC in place of the downpipe. There is still a shadow code for exhaust regain control right after the tune.

But here is a drive this morning, nothing crazy, but some data. I can do some full fuelling runs as well. Although, someone with an Ecotune and downpipe should be able to provide you a better reference sample.

Note: the first little bit there is zero rpm as I was monitoring a different parameter, so ignore the first part.



And this is turbine speed vs exhaust back pressure. I believe this is for the low pressure stage. You can also monitor the turbine control valve proportion between the high pressure and low pressure stages if that is useful

[TDIwyse]

Originally Posted by Yozh

I would be happy to provide what I have, but I doubt I am a good reference. As you may recall I was tripping limp and code 4530 and have now eliminated the problems and double check all of the controllers. I'm also running gutted DPF with DOC so I'm going to have a bit more back pressure. Still running rich though, so I'm thinking it is either the SCR plugged by urea and soot or the tune does not like my DPF/DOC in place of the downpipe. There is still a shadow code for exhaust regain control right after the tune.

But here is a drive this morning, nothing crazy, but some data. I can do some full fuelling runs as well. Although, someone with an Ecotune and downpipe should be able to provide you a better reference sample.

Note: the first little bit there is zero rpm as I was monitoring a different parameter, so ignore the first part.

Attachment 1142379

And this is turbine speed vs exhaust back pressure. I believe this is for the low pressure stage. You can also monitor the turbine control valve proportion between the high pressure and low pressure stages if that is useful

Attachment 1142399

Thanks!

Do you know the units on the pressure?

I had watched the turbine control valve with Bav Tech. Hadn't looked for the drive pressure or turbine speed ... Might have to go to put back on the BMWhat for some of this ... Guess I have some more data to collect :-)

iaknown, do you have BMWhat or a way to measure these parameters? would be interesting to gather some data from multiple vehicles.

[DWR]

Originally Posted by Yozh

And this is turbine speed vs exhaust back pressure.

Yozh, the graph says engine speed, but you've said turbine speed. I'm unaware of a turbine speed sensor? The values look like engine speed. Too low for turbine rpm unless there is a multiplication correction factor. Please clarify. Thanks.

[Yozh]

Originally Posted by TDIwyse

Thanks!

Do you know the units on the pressure?

hPa

[Yozh]

Originally Posted by DWR

Yozh, the graph says engine speed, but you've said turbine speed. I'm unaware of a turbine speed sensor? The values look like engine speed. Too low for turbine rpm unless there is a multiplication correction factor. Please clarify. Thanks.

Good point, I'll have to check rpm vs the turbine speed.

Edit: here is a plot of rpm vs turbine speed, they seem to be different. I also do not see a specific sensor that monitors the speed of the turbine. May be they derive it from some other parameters.

[iaknown]

Originally Posted by TDIwyse

iaknown, do you have BMWhat or a way to measure these parameters? would be interesting to gather some data from multiple vehicles.

I do but my car is still in pieces. Will do some logging once I get it back going.

I've never heard of a turbine speed sensor on our cars, that would require wires off of the turbo somewhere. I know other BMW's have it though. The software must be reading the same PID, so who knows what that would be on our cars....

[TDIwyse]

Yozh helped me out with BMWhat log stuff. Thanks.

I agree the turbine speed data I'm getting from BMWhat can't possibly be correct... It's way too low.

But the turbo pressure stuff is interesting. I just wish BMWhat updated the parameter log faster as it's not catching a lot of the information even in a 4th gear pull. Maybe I can find a really steep hill to slow the time to accelerate down ...

Here was some messing around a bit this afternoon with some turbine stuff at moderate applications of the skinny pedal. The left Y axis is in psi and is absolute pressure (so it includes ~14.7 psi from normal atmospheric pressure), the right is the ratio of drive pressure to boost pressure (calculated). From what I've gathered you'd want to keep that ratio below ~1.5:1 ideally, with some saying up to a 2:1 is ok for short bursts...



Will try to get more data in the next few days.

[DWR]

Originally Posted by Yozh

Edit: here is a plot of rpm vs turbine speed, they seem to be different. I also do not see a specific sensor that monitors the speed of the turbine. May be they derive it from some other parameters.

I'd say they track too closely for it be anything but a derivative of engine rpm. That kind of response looks more like a crank driven centifugal supercharger than an exhaust driven turbine!

[DWR]

Originally Posted by TDIwyse

I just wish BMWhat updated the parameter log faster as it's not catching a lot of the information even in a 4th gear pull.

I wish we could get the PIDs for these parameters and use Torque ...

[DWR]

Originally Posted by TDIwyse

From what I've gathered you'd want to keep that ratio below ~1.5:1 ideally, with some saying up to a 2:1 is ok for short bursts...

I think for the calculation you are doing (drive pressure across the system and not across the turbine), it is not unusual to see close to 2:1, in remaps without or with minimal exhaust modifications. Based on the data you and iaknown have provided on exhaust modifications, it looks like those mods might be improving that ratio.

[Mik325tds]

@DWR
Would a CAN log help? I could try to make one tomorrow.
Does BMW use UDS?

[Mik325tds]

Strange. I can't find drive pressure as an EDIABAS job. But it does give me the current charge-air pressure.

[stevers314]

I suspect the turbine speed is related to the input shaft on the transmission and not either of the turbochargers. From the graphs it appears to be at a stall speed during idle and the differing peaks make me believe that's the wonderful slipping going on in lower gears.

[Hoooper]

Stevers that was my thought as well. It appears to be the output speed from the torque converter

[TDIwyse]

Ugh BMWhat has really slow data sampling.

This is an example 4th gear full fuel run from this afternoon. Drive Pressure to Boost pressure ratio looks good with the EWG in play. It at least is capturing a data point near to where the "spike" used to be (at ~2800 rpm) but I was letting off the fuel before the next rpm point due to speed issues.

Did I mention the sampling period is SLOW ... Would really need to find a 20% grade hill and tow a trailer to make a pull slow enough to get more sample points ...

[iaknown]

BMWhat logging sucks in my opinion. The resolution is just horrible. And Torque can't be trusted with too much accuracy because it is a universal CAN program and for it to work a conversion is taking place which affects accuracy.

For honest logging the only thing to use is INPA w/Ediabas.....Test-O (as shown above) is incredible for this. Since it works through INPA it shows the true values and take any conversion errors out of the equation, plus the resolution is incredible.....

[TDIwyse]

iaknown, would you give us a tutorial or point us to a good reference on how to setup/use/purchase INPA?

[DWR]

Originally Posted by TDIwyse

iaknown, would you give us a tutorial or point us to a good reference on how to setup/use/purchase INPA?

Yes! Please and thank you.

[Yozh]

Originally Posted by TDIwyse

iaknown, would you give us a tutorial or point us to a good reference on how to setup/use/purchase INPA?

Yes please. I even have a D-Can cable.