SD Tune AFR stability at WOT?
SD Tune AFR stability at WOT? Tuning a turbo LQ4, running a 11.1 (.76) AFR at WOT. When going WOT, it jumps around from .74 to .76 - it seems very hard to get it to be dead set at .76 the entire time the throttle is wide open when tuning the VE table. Also, when converting the .74 and .76 to AFR.. we are talking about a sweep from 10.83 AFR to 11.23 AFR (all because lambda is shown in two decimal points, so it rounds up/down). Just seems like lambda isn't a good thing to go by since it only goes by 2 decimal points. Maybe I need to increase my lambda error decimal points out to .xxxxx instead of .xx ?
The turbo truck I had before, which was tuned by a shop - had a 11.1 AFR at WOT and it was dead set on 11.1, didn't move around at all on my wideband gauge. I believe that tune was MAF though
Is it normal for an SD tune to not be 100% on the money as far as VE table is concerned?
The turbo truck I had before, which was tuned by a shop - had a 11.1 AFR at WOT and it was dead set on 11.1, didn't move around at all on my wideband gauge. I believe that tune was MAF though
Is it normal for an SD tune to not be 100% on the money as far as VE table is concerned?
Last edited by TXjeepTJ; Sep 14, 2017 at 10:01 AM.
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
Always street tune. I use the predefined AFR correction table for VE (and MAF if applicable). I do multiply by percentage then once i get to 7 or below percent correction I multiply by half percentage. Goal is to be around 2% error. Go back and hand smooth once youve reach all the table you can. Done. AFR will be perfect.
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From: Turnin' Wrenches Infractions: 005
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Sorry to hijack this but there are a few of you on here I follow and wow I've been away too long lol.
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Verdad Gallardo Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
Start at page 17/18 of my thread in the multi media section, its usually right at the top. Turbo build starts there, whew its been a long journey!!!!
Thats pretty rich. All widebands use lambda and display AFR. They are just scales, once is not more accurate than the other. In SD your fuel should equal your commanded and it should look like a flat or single line when overlaying them on the data log or very close to it. You may have to hand smooth your VE table, run filters, get better or more data, or multiply by a smaller % but your fueling shouldnt be all over the place.
OP if you're AFR is moving around like that then either the boost or the fuel pressure is likely moving around too. Like trying to hit a moving Target. Is your fuel pressure regulator boost referenced?
Other way around....all stock fbody tunes ignore the map above 4k as stated. MAF is better at steady states and WOT is one of them.
OP if you're AFR is moving around like that then either the boost or the fuel pressure is likely moving around too. Like trying to hit a moving Target. Is your fuel pressure regulator boost referenced?
OP if you're AFR is moving around like that then either the boost or the fuel pressure is likely moving around too. Like trying to hit a moving Target. Is your fuel pressure regulator boost referenced?
Whats your logging channel count? If you go over like 24 channels it will slow the data rate which will also make your AFR jumpy.