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Thread: What should AE AFRís be?

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    What should AE AFRís be?

    Ok I should ask what the optimal air fuel ratio should be while in accel enrich? Or is that engine dependent? Iím currently running 1bar with code59 on a quad 4 2.3l. I have all the stuff to super charge except time to install so if you donít mind including 1bar and boost AE AFRís I would be great full. From what I have read 12.5-13.2 AFR is PE, but must have over looked AE somewhere. Feel free to correct or criticize :-) Thank you for any help!!!

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    AE is very hard to measure, as it's only at full enrichment for a moment. widebands don't really pick up instantaneous fuel changes very well. also, every engine wants a different AE. a lot of AE is just preventing things from going lean during throttle stabs. i'd go by feel. but if you had to throw a number at it, somewhere around 13:1

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    Ok that makes sense that its more feel than number. but now im wondering about the 2 AE maps, one is a tps multiplier the other is a rpm multiplier. You say i wont really c it on the wide band so does that mean that the ae multiplier x rpm is only for the stab of throttle and not extra fuel added while the car is accelerating? I was thinking that the rpm multiplier would adjust fuel as long as the car was gaining speed and i would see the afr changes on the wide band. If I am wrong what do i adjust to make the car accelerate faster after the throttle stab? what should the wide band say as the car is gaining speed...lets say at half throttle?

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    AE is just used to get you into PE (Power Enrichment). The AE TPS is for the quick stab of the throttle, That is too quick for the MAP sensor to pick up. Then the MAP AE comes in, then PE depending on where you have it set at. The AFR value you asked about is for PE. Most like to say that AE is like a carbs pump shot, and that PE is like the secondaries opening on a 4 bbl carburetor.

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    If I am wrong what do i adjust to make the car accelerate faster after the throttle stab? what should the wide band say as the car is gaining speed...lets say at half throttle?
    This should be your timing first, then PE timing, and then your PE AFR. Do you have a backfire or sluggishness when you floor it? If not you should move to PE and Timing. Also making sure your trans is adjusted right if you have a th350 or 700r4.

    And it depends on your PE settings but if you're flooring it, your wideband should match your PE AFR.

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    Ok so the AE rpm is just the the first shot of fuel at specified rpm? I do see high 11 low 12 sometimes when i press the throttle but the AE tps is almost at the bottom or zero. Whether thats from AE i dont know, wide band is pretty close to the head probably 8-10 inches in a cross tube where the 4-2-1 header goes from 4 to 2, if that matters. i have the PE set at 87% throttle, PE spark at .70. I have sluggishness mostly if i stab throttle (rarely to 100%) trying to speed up in traffic, really sluggish if im getting on highway behind someone slow and try to pass them after getting on the highway. Light throttle seems ok and if I get a clear on ramp where I can run the rpms up in each gear (5speed manual) it pulls pretty good but if i have to get out of throttle at anytime and get back into it its BLAH! No backfires tho. I have messed with timing 100kpa 4000rpm- 7000 redline and its at a place where if i advance it looses power and lower timing it looses power. have mostly been playing with stop and go traffic feel lately, advancing timing between 50 and 80 kpa and adjusting fuel accordingly has made biggest difference not ae tho so thats why im asking about AE. But from what u r saying i should b adjusting PE? Trying to tune efi i feel like has made me second guess everything i thought i knew about cars so I hope this make sense!
    Last edited by BigBanks78; 08-09-2018 at 03:42 PM. Reason: forgot something

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    Yeah, I would try removing the PE delays, and then lower when PE comes in...maybe 50-60% or 30 just to see what it does when it comes on. What was PE spark on the stock bin?

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    Ae is pump shot PE is like the powervalve on a carb richens high load.most of the stock stuff with PE that i tune comes on at 50%throttle unless at high rpm I normally cut it back a lot to 25- 30 odd percent so it comes in earlier at less load
    Last edited by delcowizzid; 08-10-2018 at 06:08 AM.

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    Quote Originally Posted by notime2d8 View Post
    Yeah, I would try removing the PE delays, and then lower when PE comes in...maybe 50-60% or 30 just to see what it does when it comes on. What was PE spark on the stock bin?
    Stock was $8B and it had a completely separate spark map for PE but at 100kpa it was about 2 degrees higher in most places if I remember right. I’m not sure what throttle % it came in at but I took it down to.7 trying to figure out the higher rpm timing power weirdness. I have only been making small changes and drive it for a week or so, I will change the PE today, I was going to try lowering the low end 100kpa timing a bit so I’ll move the pe throttle % down to 30 or 40% first. Should I add time pe timing back as well or wait to c what happens with throttle %?

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    And I’ll look at the delays and remove if not already.

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    Quote Originally Posted by BigBanks78 View Post
    And I’ll look at the delays and remove if not already.
    Yeah a few bins have a PE delay for some seconds before it allows PE to come in.

    Should I add time pe timing back as well or wait to c what happens with throttle %?
    I honestly don't know about this one. Some argue both ways. I like to have it to bump timing up a few degrees instantly when i'm accelerating and have lower overall timing in case i get bad gas or something. But others say they don't like anything else adding timing and do all of their timing in the main table and leave it at that.

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    Ok I couldn’t find the tps% for pe so either I remember wrong or I’m blind but I did a search in tunerpro for pe and changed the delays and lowered some of the kpa %’s at which it turns on and I think it feels better in some places so im gonna see if I can even out the afr, it’s all over the place

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    Changing PE stuff helped. Had some sluggish spots so lowered timing in 100 kpa in a couple spots and that smoothed it out, this thing is weird with timing, even tho it doesn’t spark knock it doesn’t like timing to high. Maybe I don’t have other things set right. I still have to add some fuel in PE from from 2800-4000 to get it to lower 13’s but after that I think I’m gonna quit bugging you guys till I get the SC installed, I know I’ll have to have help with all the settings then!
    Thanks for all the help guys!!

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    It is entirely possible to exceed MBT on good combustion chambers. Higher is not always better.
    1995 K1500, Cadillac 500 TBI with 4L80E swap. In progress.

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    I’m finding that out :-) I’ve taken the timing up until it spark knocks in a lot of the 100kpa but that did not make it run better after backing off a bit. After changing changing the PE settings I am now pulling timing back down and it is running much better. This last time I changed the chip I tried modeling the 100kpa timing after the PE timing table in $8B instead of main timing table (thought of that after reading notime2d8’s reply) and it seems to be accelerating much better. And lowering it as well.

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