Where is the PE stuff in the 8746 ECU? I can't find it anywhere in any of the ECU's I have for TunerPro RT. I need to bump the %TPS up and I can't seem to find the constant.
TIA...

 

Okay, I think I may have found it. I was using the 8746jonprevost ECU and I switched ECU's to the 8746.ecu file. It has two tables in it that enable PE. They are "TPS% for PE mode vs RPM (low temp)" and the same for high temp. I also saw a TPS PE hyst constant. What is that and what does it do? I am trying to start tuning the Jeep with all the variables already established for tuning...like changing the PE enable to higher values so it won't screw with my first attempts at VE table logging and tuning.

 

Okay, I think I may have found it. I was using the 8746jonprevost ECU and I switched ECU's to the 8746.ecu file. It has two tables in it that enable PE. They are "TPS% for PE mode vs RPM (low temp)" and the same for high temp. I also saw a TPS PE hyst constant. What is that and what does it do? I am trying to start tuning the Jeep with all the variables already established for tuning...like changing the PE enable to higher values so it won't screw with my first attempts at VE table logging and tuning.
EDIT: I found it in the other ECU now. It is just under a different heading. Something like "TPS threshold for WOT Mode."

 

The hyst constant is the amount of TPS you are able to decrease by (lifting the go pedal) and still stay in PE. IOW: once in PE mode this term is subtracted from the 'go-into' PE mode TPS term vs. RPM. Then the TPS is required to fall below this value before exiting PE.

Hard to explain, hope I didn't confuse. . .

RBob.

 

Thanks, Rbob. I actually do understand it. The last line made it all perfectly clear. So, the hyst is subtracted from whatever TPS the ECM senses when going into PE mode. The TPS is required to fall below the calculated value before falling out of PE. Right?
I am going to edit that item in my ECU and put this statement in there as a comment so that I'll remember it later.
Seems like this could be really useful for tuning the PE later in the game.

 

Correct. An example would be where 30% TPS is required to go into PE mode, with a 3% hysteresis term.

Once the TPS is above 30% the ECM will go into PE mode. The TPS% now needs to be below 27% to exit PE mode (30% - 3% = 27%).

GM uses hysteresis terms a lot. Prevents a mode from chattering in & out.

RBob.

 

Hmmm...hysteresis loop, maybe? I can't believe I didn't pick up on that before.
I may be getting the hang of this stuff.