desTRUCKtive

What does PE stand for in tuning? I know that VE is Volumetric Efficiancy.

horist

PE = Performance Enrichment. When you go WOT (or anytime driving under heavier loads and TPS) you enter PE mode. The PCM then adds additional fuel to richen the mixture up (ideally it should be 14.7:1 / PE scalar = requested AFR , but unless the VE table is 100% on the ball this isn't exact)

JimMueller

iTrader: (9)

I've also heard it called Positive Enrichment or Power Enrichment. Seems like each software package uses a different term.

horist

I have no idea why I said performance enrichment... Power enrichment is what I've always heard it as... I must have been reading something else when I typed this response heh...

RedHardSupra

iTrader: (1)

i wrote up something the other day on the topic, might wanna take a look: http://redhardsupra.blogspot.com/200...universal.html

desTRUCKtive

Where did you put the links for those PE settings on the page?

Sotiri

Is it the same as open loop?

white2001s10

iTrader: (4)

Not neccessarily. It's a modifier that adds fuel similar to the coolant temp enrichment table, except it's based on load & RPM instead of coolant temp. It's another fuel adder that is triggered by changing load conditons such as going WOT.

RedHardSupra

iTrader: (1)

i meant to do it and then i didn't but now they're there, take a look.

txhorns281

iTrader: (12)

and it will add fuel as the multiplier commands, but not take away fuel... I wouldn't call it "learning" though. Depending on how the VE is tuned in WOT areas, the PCM has the ability to add fuel up to the injector's capacity for commanding richer and richer WOT AFR

Sotiri

So the only time it is in open loop is at startup? Why do people say it goes into open loop at WOT?

horist

you're in Open loop at WOT also

Open loop basically means it's not using the O2 sensors to determine fueling. It's relying on built in tables (VE and PE amongst them) and calculated Load values from the MAF and MAP to determine how much fuel to add

PE is enabled when TPS is > xx% depending on engine coolant temp and other variables

Sotiri

I'm going to try running open loop all the time at the track (setting closed loop enable temp. at 151 C)... Should i expect better e.t.? more consistancy?

white2001s10

iTrader: (4)

You won't get any learned fueling corrections so you'll have to do more work on the fueling tables.
If you also eliminate the other variables that affect fueling, then yes it would be more consistant, but simply running open loop does not automatically eliminate them... only the learned fuel trims.

94white28

what are the advantages of running an Open loop only tune???

foff667

iTrader: (2)

your not at the complete mercy of the computer..you enter what a/f the motor should be at in individual cells...also when going to larger cams the overlap can confuse the stock o2's to the point where it cant make up its mind on how much fuel to add or even what mode to stay in. And if your talking a mafless tune your talking about one less restriction in your intake setup meaning more air.

Sotiri

So in other words, % change in fuel at WOT remains even at open loop? ( all my other variables are zeroed)

white2001s10

iTrader: (4)

No, I told you they don't. You have to take care of those things by tuning them out.
For instance you want to eliminate the coolant variable in the range of 140*F and 200*F, then you have to make all those cells the same number to zero out the variance so changing coolant temp will not change the fueling. It's not automatic.

edit: maybe I'm not understanding your last post, sorry if that's the case.