I have read that some fellows set their PE % change to Fuel/Air ratio vs coolant temp to "0"

Can I take the percentage from "coolant temp" and add it to PE % change to Fuel/Air ratio vs RPM without changing my AFR???

My AFR is set to 13.0-13.2 at WOT and would want to keep it there.

 

You did not provide you year and model info.. I will answer using my setup..For an OBD1 using TunerCat $EE you can select help - calibration help - tables - % Change to AFR to view this information. The AFR at WOT is determined by the following formula " WOT AFR = 14.7 / (1 + %Change vs Cool/100 + %Change vs RPM/100) " Therefore if you 'zero' out the AFR vs coolant table settings then the AFR vs RPM settings will control the WOT AFR. This simplifies making changes as you only have to alter one table not two when tuning. EG. with AFR vs RPM setting for 5200 RPM at 13 and AFR vs coolant zereo'ed out, WOT AFR = 14.7/ (1 + 0 + (13/100)) = 14.7/1.13 = 13.0 AFR. OR setting of 11.3 = 14.7/1.113 = 13.2 AFR. So by zero'ing out the coolant table the RPM table selects the AFR. But then you give up the option of running a richer PE AFR when the engine is cold. You need to understand the implications.

 

bobdec, thanks for the quick reply.
Yes, I have OBD1 and I'm using TunerCat ECM DA2 with BLM locker. It's a 1992 LT1.
I know the formula but wasn't sure if it really would work. I'll check it out with my wideband just to make sure after I make changes.

You know, I'm sorting out all the issues I have one at a time. Ever since I changed to the bigger cam, cam surge is my biggest problem. Maybe I'll just start a new thread and ask for more help.

BTW, anyone stepping on the gas pedal in such a manor (WOT) while the engine is cold isn't very smart.

 

They should have a table for %Change to F/A ratio vs IAT at WOT, that would be much more usefull.

Hal

 

but they don't