Power Enrichment Question

[Allen Vos]

Just a few PE questions. Here is a screen shot of my PE Tab with the ECM 12400 PE EQ table and the ECM 12420 Hot PE Enable TPS Threshhold.

Attachment 142802

This is bone stock and has not been touched.

Looking at the MAP and RPM enable, PE appears to be on at all times?

Is the ECM 12420 table an indicator of when PE is activated by TPS?

Also looking at the ECM 12400 PE EQ Ratio, Things seem awfully rich for a stock setup.

The peak torque area of my engine is roughly 4600 RPM and EQ is calling for 1.3 which equates to an AFR of 11.2:1

I can remember tuning a boosted V8 a while back and we were shooting for 11.7:1 AFR at peak torque with Max boost

I did not expect to see a NA motor this rich.

Am I reading this correctly?

I see the delay is set to "0" so I am assuming all the delay values dont mean anything as the delay is "0" and will never really be a delay?

[hjtrbo]

Looking at the MAP and RPM enable, PE appears to be on at all times?

Is the ECM 12420 table an indicator of when PE is activated by TPS?

Activated by tps. We usually get rid of the delay timers (yours are 0 anyway) and some increase the ramp in rate. Trap; the TPS is not TPS in the scanner. One day i'll dig into the binary to make sure, but I'm bloody sure it's throttle effective area. I don't have that available in my channel list, you might have it.

The peak torque area of my engine is roughly 4600 RPM and EQ is calling for 1.3 which equates to an AFR of 11.2:1

That's why we tune them. Goes without saying, afterwards we will always use premium fuel.

I see the delay is set to "0" so I am assuming all the delay values don't mean anything as the delay is "0" and will never really be a delay?

Yes

[Allen Vos]

Activated by tps. We usually get rid of the delay timers (yours are 0 anyway) and some increase the ramp in rate. Trap; the TPS is not TPS in the scanner. One day i'll dig into the binary to make sure, but I'm bloody sure it's throttle effective area. I don't have that available in my channel list, you might have it.


That's why we tune them. Goes without saying, afterwards we will always use premium fuel.


Yes

That's insane that they target 11.2:1 AFR at peak torque on a N/A engine. I seem to remember you want like 12.5-12.9:1 AFR for a NA engine in the peak torque area. Does that sound correct?

What are all you N/A guys running for EQ ratio/ AFR?


I was thinking of setting my MAP to activate PE around 70 KPA and 2500 RPM.

Does that sound ok?

And definitely premium fuel all day long

[hjtrbo]

I'll defer those questions to the N/A specialists. I've only ever tuned boosted.

[5FDP]

OEM's run richer air fuel ratio's for warranty, safety and emissions reasons. They want anyone, anytime, anywhere to floor it and not have an issue.

My opinion is to run mid 12's for NA on port fuel injection. Why run it at nearly 13 AFR if the power gain is so minimal.

[Allen Vos]

OEM's run richer air fuel ratio's for warranty, safety and emissions reasons. They want anyone, anytime, anywhere to floor it and not have an issue.

My opinion is to run mid 12's for NA on port fuel injection. Why run it at nearly 13 AFR if the power gain is so minimal.

So 12.5:1 AFR would be great for peak torque areas and a bit closer to 13:1 AFR leading up to peak torque and coming out of peak torque into the higher RPMS?

Or better to stay with 12.5 AFR for all PE?

[5FDP]

Just stay with one set number, makes tuning so much easier. Plus you don't have a dyno or didn't say you have a dyno.

I'd waste so much time if I tried to tune every portion of the RPM curve to a different air fuel ratio when we are probably talking a 5-10hp difference that you can't even feel on the road.

[Allen Vos]

Just stay with one set number, makes tuning so much easier. Plus you don't have a dyno or didn't say you have a dyno.

I'd waste so much time if I tried to tune every portion of the RPM curve to a different air fuel ratio when we are probably talking a 5-10hp difference that you can't even feel on the road.

No I don't have a dyno and just street tuning it. I street tuned my old mustang with turbos on speed density and I remember setting it to be 11.2:1 AFR or so during peak torque(Max fuel consumption) and shot for 11.7:1 AFR leading up to peak torque and leading away from peak torque into the higher RPM's. Car ended up running 9.5 ET @142 MPH.

From what I recall it wasn't all that difficult, but I will start this one at 12.5:1 AFR for all of PE and then adjust from there.

I'm sure it will be much better than the pig rich 11.2:1 AFR the factory is calling for lol

[blindsquirrel]

When dyno tested, there's not even 5-10 HP difference in the range all the way from 10.5:1 through 13.5:1, difference is basically no more than the normal discrepancy between two back to back dyno runs with the exact same AFR. If you can stand to watch RICHARD HOLDENER videos, it's been demonstrated many times...

The difference between lean at WOT and rich at WOT, on a N/A LS engine, is only a balance of safety against fuel consumption, not power.

[hjtrbo]

If you can stand to watch RICHARD HOLDENER videos

Lol, he smiles to much and has to much energy for my tastes. And on the subject, I've had a gutful of Gale Banks popping up in my feeds harping on about air density like it's something new. No fucken shit sherlock.

[blindsquirrel]

You know, in his live streams, he's not totally awful. But his edited videos are... not good. I keep waiting for him to have a meth OD on screen and I really would rather not have to witness that, thanks.

[JayRolla]

So 12.5:1 AFR would be great for peak torque areas and a bit closer to 13:1 AFR leading up to peak torque and coming out of peak torque into the higher RPMS?

Or better to stay with 12.5 AFR for all PE?

Like the others stated just target the same AFR. No reason to get all fancy with it and power gains are negligible. I even target a bit rich around .82 lambda. I also would suggest throwing AFR out the window with alcohol being in almost all fuels.

[edcmat-l1]

LS3s and LS7s I target low 12s depending on what the vehicle will be used for. Road race stuff I target exactly 12:1 and don't mind if it's a touch richer. Both LS3s and LS7s will make LESS HP at 13:1 than they will at 12:1. They just don't like being that lean.

[Allen Vos]

Like the others stated just target the same AFR. No reason to get all fancy with it and power gains are negligible. I even target a bit rich around .82 lambda. I also would suggest throwing AFR out the window with alcohol being in almost all fuels.

Im not tuning in AFR. Tuning in EQ ratio as per the LS3 tables, but your .82 Lambda would be 1.2 EQ ratio or 12.1 AFR

[Allen Vos]

LS3s and LS7s I target low 12s depending on what the vehicle will be used for. Road race stuff I target exactly 12:1 and don't mind if it's a touch richer. Both LS3s and LS7s will make LESS HP at 13:1 than they will at 12:1. They just don't like being that lean.

Really good to know this stuff. We used to tune the old SB Chevs and Fords for almost 13:1 AFR. But as I am learning the LS's are different.

I was quite surprised to find the EQ ratio for the stock LS3 at 1.3.

That's 11:1 AFR and quite rich in my books.

I didn't even tune my old turbo stang that rich and it went consistent 9.5's @ 142 MPH

But 12.1:1 AFR is a good safe ratio that leaves a bit of room to lean out and not hurt things

[Allen Vos]

Lol, he smiles to much and has to much energy for my tastes. And on the subject, I've had a gutful of Gale Banks popping up in my feeds harping on about air density like it's something new. No fucken shit sherlock.

Ha Ha, he does seem like an odd duck

[Allen Vos]

I forgot to ask all you guys, Where do you guys set PE RPM to engage or do most of you guys just run it off the MAP sensor values?

I was thinking like 2500 RPM, but if the throttle gets floored at say 2000 rpm PE would be needed.

[Cringer]

I forgot to ask all you guys, Where do you guys set PE RPM to engage or do most of you guys just run it off the MAP sensor values?

I was thinking like 2500 RPM, but if the throttle gets floored at say 2000 rpm PE would be needed.

IMHO for N/A...

.85 lambda / 1.18 EQ Ratio all RPMs

NO DELAYS

[sgod1100]

I forgot to ask all you guys, Where do you guys set PE RPM to engage or do most of you guys just run it off the MAP sensor values?

I was thinking like 2500 RPM, but if the throttle gets floored at say 2000 rpm PE would be needed.

With my ctsv I have mine triggered solely from the map setting. I do this because if you are on the highway cruising in 6th gear it takes VERY little pedal movement to get into boost. I don't want to rely on pedal in this case as I'll be at stoic when getting into boost. I have mine at 90 kpa if I recall

[hjtrbo]

I haven't played with the rpm so I could be wrong, my thoughts are; since delay timers are 0, changing the rpm delay will no effect. I don't see any harm in setting it to 0 though. This is something you would need to test for me so I know for next time.