Question about PE

[Ghostnotes]

Going back through the tuning school books, in the power enrichment section it says to set your EQ ratio to a single ratio. So if i want 12.0:1, it basically says to set the entire table to 12.0:1 from 0 rpm on up. Now I know there is a ramp time but do i really want to go into PE at 100% throttle at 1000 rpm?

Shouldn't this have some sort of ramp in as well? I saw this on a GEN V camaro a while back that had the TS school tune. I left it alone since all they needed was their MAF dialed a little. Now I'm going back over mine...little by little and was just wondering if that should be different.


Thanks.

[5FDP]

In some cases I will have the throttle % enable higher at lower rpm and lower at higher rpm so it can get right back into PE if I had to let out. Or I will just leave it at 60-65% for the entire table like in a NA truck.

I keep the EQ ratio at a target for most of the rpm range but lean it out up top. Like going from 12.4 up to 12.8.

[Ghostnotes]

Got it.

[Jonblarc7]

In some cases I will have the throttle % enable higher at lower rpm and lower at higher rpm so it can get right back into PE if I had to let out. Or I will just leave it at 60-65% for the entire table like in a NA truck.

I keep the EQ ratio at a target for most of the rpm range but lean it out up top. Like going from 12.4 up to 12.8.

What do you think you would target for PE lambda in a NA L86 cammed. The reason I ask is right now I'm I have my PE set to 1.140 so .86 lambda from 2,560 up. And this gives me a big cloud of black smoke from a WOT hit. Not Diesel Black but like a cleaner burning Diesel. But still enough where I'm like I don't think it should smoke out an intersection like that. WOT it the only time it smokes like and on E85 it doesn't do it hardly at all.

PE.png

[TriPinTaZ]

I usually start out leaner and ramp the PE table to the desired PE by about 2500 RPM. For example Start at 1.10 and scale to 1.15 for moderately boosted application. Your MAF needs to be dialed in to get a flat Lambda line from 2500 to redline though. The reality is if you stomp the gas from an idle you are spending little to no time below 2500 RPM anyhow. I turn up the ramp in rate on the PE target and disable the dealys as well. I don't think anything higher than 1.0 on the Gen v's ramp in rate actually makes it reach target faster but removing the delays certainly do. I usually set ramp in rate to 1.5 or 2.0 so that I feel better. But I'm not convinced it actually changes anything. I feel like 1.0 = as fast as possible already. I could be wrong so don't hold me to it.

[TriPinTaZ]

What do you think you would target for PE lambda in a NA L86 cammed. The reason I ask is right now I'm I have my PE set to 1.140 so .86 lambda from 2,560 up. And this gives me a big cloud of black smoke from a WOT hit. Not Diesel Black but like a cleaner burning Diesel. But still enough where I'm like I don't think it should smoke out an intersection like that. WOT it the only time it smokes like and on E85 it doesn't do it hardly at all.

PE.png

Alcohol burns cleaner but sounds like a dump of fuel. .86 is rich for a NA DI motor IMO. I would go to at least .88-.90 but depends on what the car likes. Also, do your math based on 14.1 stoich if you're running E10. .86 would be 14.1 x .86 = 12.1 AFR. That's pretty rich for a NA DI motor. Try setting the EQ ratio to 1.120. 14.1 / 1.120 = ~12.6 AFR. Look at how much torque and pedal is required to to initiate PE mode as well. If you're starting it way early the engine may not be able to efficiently burn it all until air velocity speeds up and spark is more optimal. This is usually why OEM tunes have delays in PE as to avoid the puff of emissions. You will get more of a puff when disabling delays but it shouldn't be extreme at all.

[Jonblarc7]

Thanks

Torque % is 20%

Enable Pedal is 30% until 2,048 then goes down.


Pe pedal.png

[TriPinTaZ]

Thanks

Torque % is 20%

Enable Pedal is 30% until 2,048 then goes down.


Pe pedal.png

Yeah that's too soon. You should be at like 65% throttle position at lower RPM and maybe ramp to 50% from 4000-redline.

The torque number is awfully low too. It only needs to be lowered if your torque model is changed. But the TPS % is where your problem is.

[Ben Charles]

Going back through the tuning school books, in the power enrichment section it says to set your EQ ratio to a single ratio. So if i want 12.0:1, it basically says to set the entire table to 12.0:1 from 0 rpm on up. Now I know there is a ramp time but do i really want to go into PE at 100% throttle at 1000 rpm?

Shouldn't this have some sort of ramp in as well? I saw this on a GEN V camaro a while back that had the TS school tune. I left it alone since all they needed was their MAF dialed a little. Now I'm going back over mine...little by little and was just wondering if that should be different.


Thanks.

They give a lot of bad info... never should a PE table be set to the same value throughout

[Ben Charles]

Also the DD table and how agressive you are with it will dictate PE settings

[Jonblarc7]

The Torque% at 20% was the stock setting before I had the tuner tune it for the cam. I compared it to any older tune I had for enabling E85. Should I raised it.


Here is what I did for Enable Pedal

PE PEDAL.png

[TriPinTaZ]

The Torque% at 20% was the stock setting before I had the tuner tune it for the cam. I compared it to any older tune I had for enabling E85. Should I raised it.


Here is what I did for Enable Pedal

PE PEDAL.png

Seems awfully low but the PE logic is [if Pedal is above X% and torque request % of maximum is met, then enter PE.] So you can leave it at 20% if you're comfortable there. Typically I see this in the 50-70% range but I lower it if I ever mess with Torque Tables or change the airflow model drastically.

[HeavyChevy305]

They give a lot of bad info... never should a PE table be set to the same value throughout

Exactly. It's set the way it is for a reason. The ECM references other tables simultaneously to achieve the desired equivalence ratio commanded.

[Ghostnotes]

They give a lot of bad info... never should a PE table be set to the same value throughout

I figured as much since even during my early racing days and GEN III/IV I never set a flat rate. My enable pedal is no less than 60% below 3500 from there its 40%.

Looks like my enable torque was zeroed out by a previous tuner. I don't think that's a bad thing if logic is...IF you are above 0 torque but 60% throttle, under 3500RPM...enter PE.

[Ghostnotes]

Also the DD table and how agressive you are with it will dictate PE settings

I found that out by accident. I could actually feel it kick in (manual trans). At first i thought it was some kind of a torque spike but it was a result of me adjusting my DD and PE. It never went lean but the PE came in very fast and hard.

[Ghostnotes]

Was thinking of something like this.

[Ben Charles]

That’s never how I would set one up....

[Jonblarc7]

So would you leave it stock say from 0 to 2048 then adjust the rest of the PE table to what you are trying to target?

[Jonblarc7]

If I'm commanding 1.12 in PE above 2,560 rpms.

Then why when I'm logging does Equivalence Ratio Commanded show right around .85 instead of the .88 I'm asking for? My wideband reads pretty close to what it is commanding.

[ShaneB]

Cot?