Power enrichment and meth, i need it leaner but its not letting me

[kenand1988]

2015 z06

How I am tuning the meth is with power enrichment. I prefer to do it that way. I recently made some changes to how the meth gets delivered and got rid of the solenoid and opted for a window switch since with boost it was just never quick enough. Now though its very rich, about .7 lambda which is great now I have a lot of fuel but the eq commanded by the car isnt reflecting what i'm telling it to do under power enrichment gas and alcohol (i run e too). There seems to be a hard limit somewhere that it will not let eq go leaner than 1.0. I need to remove that. yes i know, dangerous stuff. I've tried lowering minimum eq for knock enrichment and cot (even though its not on). Do I have to play around with the open/loop tables? I do realize I could just take some out of the MAF but I would have to take out a lot and the tq tables might not agree with it.

[Ben Charles]

Open loop tables bottom out at 1.0 warm typically

[kenand1988]

Open loop tables bottom out at 1.0 warm typically

That's what I'm getting at. So the ecu is using whatever is the richest fuel pe or open loop gas/alcohol which is causing me to run into this limit of eq commanded not going leaner than 1.0

[Ben Charles]

That is correct

[kenand1988]

That is correct

Just curious Ben, what's your preferred way of tuning meth? With the pe table or maf?

[Ben Charles]

Just curious Ben, what's your preferred way of tuning meth? With the pe table or maf?

Use both… large amounts of meth (say 2 15gph of 100% meth changes AFR 2 full points) so I will pull from PE and MAF… then clean up tq model with VT tuning..
if just spraying little bit of meth can do it with PE fairly easy

When I remote tune I get asked weekly why we target .95 lambda in boost on a heavy meth car and have to have this convo..

[kenand1988]

Use both? large amounts of meth (say 2 15gph of 100% meth changes AFR 2 full points) so I will pull from PE and MAF? then clean up tq model with VT tuning..
if just spraying little bit of meth can do it with PE fairly easy

When I remote tune I get asked weekly why we target .95 lambda in boost on a heavy meth car and have to have this convo..

It's two 14gph nozzles. Before when I had an inline solenoid it was spraying less than it is now with no solenoid even though I had dc set to 100% at 6 psi and I'm at 16psi. I wanted to avoid taking it out of the maf as much as possible. I thought VT mainly effects timing so what is it you are cleaning up?

[Ben Charles]

Go do a pull a post a log I’ll point out why VT is important…

[EliteTunedSchool]

You can use the PE or MAF, whichever you prefer, especially if you are a stick car, being an auto car you need to pay more attention if you pull it out of the MAF as the reported torque will plumet, which you can correct in the torque model.

If you are hitting a PE floor of 1.0 you will have no choice but to pull the remainder out of the MAF, dont be afriad to do so.

[kenand1988]

You can use the PE or MAF, whichever you prefer, especially if you are a stick car, being an auto car you need to pay more attention if you pull it out of the MAF as the reported torque will plumet, which you can correct in the torque model.

If you are hitting a PE floor of 1.0 you will have no choice but to pull the remainder out of the MAF, dont be afriad to do so.

Are you saying the pe floor cannot be made leaner? I tried what I had mentioned to Ben about changed the open loop eq gas and alcohol tables and that had no effect.

[EliteTunedSchool]

Are you saying the pe floor cannot be made leaner? I tried what I had mentioned to Ben about changed the open loop eq gas and alcohol tables and that had no effect.

truthfully never spent much time trying to go leaner than 1.0, just pull the rest out of the MAF and watch your reported torque and adjust as necessary, you are making it more complicated than it needs to be honestly.

[Ben Charles]

Are you saying the pe floor cannot be made leaner? I tried what I had mentioned to Ben about changed the open loop eq gas and alcohol tables and that had no effect.

I NEVER go leaner then 1.0… .95 about lean as I go..

Agree with Elite, making it harder then it should.. main thing is make sure fuel is right on WB and requested Tq is in the correct ballpark

[kenand1988]

I NEVER go leaner then 1.0? .95 about lean as I go..

Agree with Elite, making it harder then it should.. main thing is make sure fuel is right on WB and requested Tq is in the correct ballpark

Alright so I was able to make a pull after setting PE to 1 and taking some out of the MAF. I do see airmass dropped from 1.6 to 1.28 so it follows that the tq reading is much lower. I still get full timing though. I will attach the log and my current tune which I made more MAF adjustments to after this log. I also took a stab at the VT. I wasn't sure if I needed to do the 0 or 7 degree intake cam setting because its mostly around 7 during wot so I just altered the intake 7 degree airmass models NOT the MAP models since those are based off kpa which hasnt changed. I basically increased everything from 1.2 up until it reached the same level as what the 1.6 row was. When I calculated the tq tables all of the rows changed to make the model smoother. I'm not sure if that is how it's supposed to be done but it is what made sense to me. Someone else can chime in maybe and tell me the correct way to do it. Also I'll take any suggestions for cleaning up that lean spike on tip in. enrichment rate is maxed out.