RedRallyeZ

iTrader: (20)

Very new to tuning, but bought HP tuners pro and have been injesting as much info as I can via here, HP tuners forum, and few YouTube channels.

Starting to wrap my head around PE table and its functions and as I look at my tune, it seems to be excessively on the rich side. see below:

1.4853515625 1.4853515625 1.4853515625 1.4853515625 1.4853515625 1.4853515625 1.4853515625 1.4853515625 1.4853515625 1.443359375 1.416015625 1.375 1.375 1.375 1.375 1.333984375 1.333984375 1.333984375 1.333984375

The story behind the car is that it was dyne tuned by Hawk's performance in 2009 as an A4 stalled car. Dyno tune happened at the same time heads and cam went in. I switched to an M6 and the car hasn't been driven much due to various reasons, but I'm back in it now. My work in progress tune is copied below.

I have a Wideband installed now so I can go log some data, but I have a Racetronix pump/hotwire kit and 36lb injectors ready to go in first. I know I'm at or beyond the limit of stock fuel, just haven't had a chance to put them in yet. I suspect that any logging I do will be skewed by fuel system not being able to keep up. Even so, when I compare my PE table to the files available in the repository, they seem really rich. 14.72/1.485=9.9AFR.

Am I missing something? im getting started with MAF then VE tuning once the new fuel system is in, but I think my PE table has a lot left to give before I even get moving.

Darth_V8r

iTrader: (4)

Try 1.25 as a start. Honestly I like 1.17 on NA gasoline

RedRallyeZ

iTrader: (20)

do you know why the tuner may have started so far on the rich side? Just going covering himself?

AgFormula02

iTrader: (13)

he may have been trying to make up for a less than perfect fuel system. Not the smartest way to do it , but who knows.
I would not change it yet. PE is just a multiplier.
Leave as is, do a wot pull, see where rear AFR is and compare to commanded AFR.
My concern to a drastic change is that if you have this 1.4xx factor and it barely keeps 13.2 AFR at wot (just and example) changing to 1.2x or lower) may put you critically lean.
Until you can compare/validate vs a real wideband reading, you don’t have a point of reference.

RedRallyeZ

iTrader: (20)

understood. From what I can gather about what PE is and what it is used for, that makes sense.

Ive logged a few pulls while scanning and had to get off the throttle quicker than I wanted to, but even when limited by traffic and road conditions, short WOT stints put me up over 93% IDC. Im not going to worry too much about gathering data now when there's no way for my fuel system to keep up.

Ive got the pump and injectors on my workbench, I just have to find an afternoon to do it. The tank is full from winter storage so I wanted to drain it down a bit before I dropped the tank.

LilJayV10

iTrader: (39)

Your IDC will go down considerably if you run a reasonable AFR like 12.8:1 or .90 Lambda, if it's actually running that rich.

ChopperDoc

Take a look at your other targets in the fuel tables. You should be commanding 12.5 (ish) on an NA car in PE. However, there may be some other wonky numbers somewhere modifying your commanded to something else (other than 14.63 stoich, and 12.5 PE), for whatever reason. Check the OL EQ table, and set it to 1.0 in operating temps. Look at other modifiers and see what they are set to as well. End of story: PE is just a modifier for commanded fuel. The air models do the rest from there, provided they are accurate.

If your fuel system can't keep up with the fueling, then commanded really won't matter. You could command 1:1 or something crazy but your injectors won't be able to do it. As stated above, the duty cycle may come down when you AFR is actually correct. If you are actually like 9:1 then that's pig rich and you can lean that up a lot. It will make more power too, so worth checking into.

RedRallyeZ

iTrader: (20)

Got it, the part about PE being a multiplier makes sense. I checked the OL EQ table and its stock. Not straight 1's throughout, but definitely not as far off as PE. I feel pretty confident that I can shift the PE table more towards the 12.5 target, but I just wish I knew why it got set so rich to being with...

RedXray

Your OL EQ settings are compounding your rich issue when in PE. When you're in PE it switches from closed loop to open loop and any value above 1.00 in the OL EQ adds even more fuel as ChopperDoc posted.

Here is the OL EQ table in my tune

ChopperDoc

In all reality, stock PE numbers are VERY rich. I’m not sure exactly why they do that, other than when they make these “cookie cutter” tunes, perhaps it’s a way of erroring on the safe side. Perhaps for warranty or maybe to compensate for narrowband O2 variations, or maybe max LTFT or something like that. The PCM adds or subtracts the last known LTFT before going into OL, and PE happens to trigger OL.

if I were you, I would get that WB going, set your targets to 12.5 in PE (1.17) and slowly work up to WOT watching your AFR closely. Then tune the airmass models as applicable the usual way.

RonSSNova

iTrader: (3)

I think GM tunes em rich for safety. Trucks can be especially rich. Imagine how rich they go when COT kicks in.

Some, maybe a lot, of Tuners simply adjust the PE to get what they desire for AFR out the tailpipe at WOT.

It works, but the tune isn’t calibrated.

I don’t tune that way. I prefer the proper way as taught by Banish years ago. In other words a calibrated tune.

RedXray

PE activation on GM trucks are set really high to around 80% throttle which is on the lean side (until PE is activated) whereas PE activation on GM cars are set much lower.