PE Values

[edv2122]

I have a 2006 C6 Corvette. So today I did some data logging and got my LTFT around 0 at a 65 mph cruise. I had to go -9% on the slope to accomplish this. Now I want to adjust the PE values and based on the general rule of thumb I should be adding +9 on the PE values. My question is won't that richen up mixute at WOT? If so why would I want to do that if the car runs better a bit lean. Can someone explain this to an amatuer tuner?

I did read the sticky on this but it I need a little further explanation.

[06MonteSS]

before you go and just add 9% to the PE ranges, do a WOT log and lets see where your O2's are reading at. That will determine how much (if any) we adjust the PE ranges.

[100LL]

Along this same topic, I've got an 05 C6 and logged the O2's for the stock tune and find the the WOT values are .87/.88 with a 12.22 Equivalence Ratio (AFR?)

When I install the 91 octane Preditor tune (and 30-40 miles to settle in) the O2's read .86/.87 at WOT with a 11.99 Equivalence Ratio.

I know that a WB sensor is the only way to get honest AFR at WOT, but the numbers above confuse me. Both sets of O2 numbers are on the low side with the Preditor tune being leaner, yet the calculated AFR (the ER) shows both are on the rich side with the stock tune as being leaner of the two at WOT

Is there any way to extract enough useful data from the NB sensors, or the Preditor in general, to at least guard against going dangerously lean if one was to adjust the PE? I'm also an amateur, am I reading this wrong?


Dan

[06MonteSS]

I would adjust the PE ranges up one or two percent to get the O2's reading at least .88xxx to be safe...

[edv2122]

OK so I did some WOT logs today and I ended up only needing to go +2 on the PE tables to get me around .89/90 on the o2 bank 1 sensor 1 and o2 bank 2 sensor 1. Soooo I went -9 on the injector slope to get me around 0 on the LTFT and + 2 on the PE tables to dial me in.

I got to say with the Diablo tune alone the car felt much peppier through the entire RPM and it feels awesome now with the car dialed in. I have not dynoed but the ol butt meter is surely showing some HP gains. Believe me I am always skeptical and this is only the 3rd time I really felt a difference with a performance mod.

I have a Vararam coming next week so I am probally going to have to tweak these values again but at least I know how to do it now.

Oh, and after a week or so of driving with the Diablo tune my MPG went up 1 and i have been hitting the throttle. Wow, better gas and performance, I love it!

[mikel]

Sweet....now wait till you feel the rush from the Vararam.
There will be no questioning that with the Butt-o-meter!

Thanks

[edv2122]

Sweet....now wait till you feel the rush from the Vararam.
There will be no questioning that with the Butt-o-meter!

Thanks

Mike
after install of the Vararam would you suggest riding around with the parameters as is till the car learns the mod OR should I do the ol negative battery disconnect and try tunning right away?

[mikel]

I'd drive around for 20-30 miles then check the trims and adjust from there.
Keep inmind that the Vararam move ALOT of air, and it may be a good idea to add a bit of extra fuel up top for when you get into high speed situations.

Thanks

[06MonteSS]

I got to say with the Diablo tune alone the car felt much peppier through the entire RPM and it feels awesome now with the car dialed in. I have not dynoed but the ol butt meter is surely showing some HP gains. Believe me I am always skeptical and this is only the 3rd time I really felt a difference with a performance mod.

Oh, and after a week or so of driving with the Diablo tune my MPG went up 1 and i have been hitting the throttle. Wow, better gas and performance, I love it!

AWESOME!!!