TCC Desired Pressure Table Axes

[David-L]

I am looking at the TCC Desired Pressure table [TCM 5672] and the axis labels just aren't making sense to me. What are they and where do they come from? I do not see any PIDs in the scanner that correlate to these names or values, perhaps I'm just missing them. One axis is labeled as "Line Pressure" and the other is "PCA Pressure". The only channels in the scanner are PCS 1-5 command pressure, TCC line pressure, and whatever fill pressure command is. There's no PCA or Line pressure.

I've read through the threads below, but its just not clicking in my head. Can anyone here explain it differently? And where does the gain of 2.045 come from in post#61 https://forum.hptuners.com/showthrea...-3000-HP/page4?? I don't see it in the editor. Is it some hard set value?

https://forum.hptuners.com/showthrea...-3000-HP/page4
https://forum.hptuners.com/showthrea...l80e-pressures
https://forum.hptuners.com/showthrea...eter-questions

Channels.PNG

[hjtrbo]

The gain value is what I take to be a close estimate of the boost ratio of the valve from signal pressure to line pressure. I.e Feed it 400kPa x 2.045 + 300 = 1118kPa. Next time you log a wide open shift with PCS1 recording, look at the shift pressure table and use the gain + offset to see how close it is...

I presume PCS A is the TCC solenoid. I have no idea of the gain / offset of that valve. I had started to make some rough correlations but gave up as I got the lock up of my stall perfect and realised that rabbit holes age me faster.

What I can say, is that the desired pressure table works and is well worth playing with, especially if an aftermarket stall is fitted. After all the fucking around I done with this table, in the end I found going back to OEM and moving everything 5 columns left and turning off TCC adapts worked best for me.

[sevinn]

The gain value is what I take to be a close estimate of the boost ratio of the valve from signal pressure to line pressure. I.e Feed it 400kPa x 2.045 + 300 = 1118kPa. Next time you log a wide open shift with PCS1 recording, look at the shift pressure table and use the gain + offset to see how close it is...

I presume PCS A is the TCC solenoid. I have no idea of the gain / offset of that valve. I had started to make some rough correlations but gave up as I got the lock up of my stall perfect and realised that rabbit holes age me faster.

What I can say, is that the desired pressure table works and is well worth playing with, especially if an aftermarket stall is fitted. After all the fucking around I done with this table, in the end I found going back to OEM and moving everything 5 columns left and turning off TCC adapts worked best for me.

I agree with you 100% here, I stopped trying to make sense of it and just shift everything over a few columns and interp up a few rows and everything is usually good to go.

[gerry_foster]

I agree with you 100% here, I stopped trying to make sense of it and just shift everything over a few columns and interp up a few rows and everything is usually good to go.

Thank you for this information, just solved my 8L90E issues

[sevinn]

Thank you for this information, just solved my 8L90E issues

That's great to hear!!