NefMoto

Hi,

I have an issue with my car. I tuned boost pid last year winter. It seemed everything is good. I haven't used the car a lot ~1000km since November. Today I logged some parameter and found that I've overboost. I've attached a picture with todays log and thelog from november. What I can see is that the requested WG duty is similar and the requested boost also, but the actual boost is over the required. What did happen?

Thank you

It looks like a N75 valve contaminated with dried oil that has formed due to infrequent use.

I've change my N75 valve. I have to do the kfldrl calibration again... :-\

This is why feed forward is a bit of a double edged sword. On one hand you get much more stable PID response as a whole, at the cost of flexibility if the hw changes.

Yes. I was stupid when just cleaned the N75 valve last year and did not buy new one. After the clean it was stable, or seems stable.

Is there any tutorial how to calibrate the original Boost PID? I can do the measure runs to get the turbo and N75 characteristic. But what to do after? How to tune KFLDRL and KFLDIMX?

Thanks

Cell values in IMX correspond the the numbers in DRL (linearization) DRL cells are output to wastegate.. so..

IF IMX is 90
DRL has columns 80 and 95,80 column has 70, 95 has 80....  you will get an interpolated result between 70 and 80.   It traces very similar to KFPED>KFMIRL>KFMIOP

Good starting point would be to take stock IMX and DRL values and divide them by difference of old gate versus new wastegate difference.

You could read through the feed forward LDR thread and extrapolate how to make it work via the information contained in there.

Thanks. Currently I have the feed forward pid. I totally understand that how it works. But as I see a little change at the system and the pid is not working properly. That's why I thinking to have the original PID and just tune it for the new N75 valve and the higher boost pressure.

Hi!

I've done the logs with the new N75 valve. I found a strange thing. With 80%DC the system generate the same pressure as 95% or a little bit higher. What could be the problem?

Thank you

Do you have the 5120 hack, because as far as i know the Stock ecu cant read more than 2560mbar, so you are at the map sensor limit

I don't have it because I don't need it. My problem is not the maximum boost. If can check the picture you can see under 3000rpm my setup generate more turbo pressure with 80%DC compare to 95%

something is very wrong with your wg, n75, or something else.

N75 valve is new. Currently I've calibrated the drl table to have a stable pid so it is working. I don't know how can I find the root cause.

Final results. I think 187g/s not bad from a k03s 18 years old turbocharger(~150000km).