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-   -   AFR difference between the banks (http://www.the370z.com/tuning/88113-afr-difference-between-banks.html)

bleunetizen 03-26-2014 11:16 AM

AFR difference between the banks
 
I find my AFR is always 0.5 richer on bank1, is this common?

this happens in open loop only, they are pretty close to each other in closed loop.

also found that MAF reading is slightly higher on bank 1 than bank 2 under open loop.

anyone with some ideas? :bowrofl:

Chuck33079 03-26-2014 11:17 AM

My tuner found a discrepancy as well. Apparently Uprev can only adjust fuel globally, so bank-to-bank variation means you have to une to the leanest bank. I'd assume there's a certain amount of variance that can't be avoided.

bleunetizen 03-26-2014 11:22 AM

thanks for the info :tup:

Chuck33079 03-26-2014 11:25 AM

Ecutek apparently can adjust fueling by bank. Mine wasn't a half point off, so it didn't make a huge difference in my tune. A half point is a pretty big difference.

Megan370z 03-26-2014 05:05 PM

Quote:

Originally Posted by Chuck33079 (Post 2754362)
Ecutek apparently can adjust fueling by bank. Mine wasn't a half point off, so it didn't make a huge difference in my tune. A half point is a pretty big difference.

Uprev can adjust fueling on each individual cylinder... just saying ;)

roplusbee 03-26-2014 05:10 PM

I really depends on how far the tuner is willing to go to adjust/set your AFR targets.

Mine is about .5 off toward bank 2. Bank one being the richer bank. Omar has been playing with my car for a bit since it has been at UPREV for the past few months. I will report in once I pick her up.

Sent from my SGH-T889 using Tapatalk

Chuck33079 03-26-2014 05:14 PM

Quote:

Originally Posted by Megan370z (Post 2755000)
Uprev can adjust fueling on each individual cylinder... just saying ;)


Interesting.

Megan370z 03-26-2014 05:25 PM

Quote:

Originally Posted by Chuck33079 (Post 2755009)
Interesting.

top right :)

http://www.the370z.com/members/megan...ure55763-1.jpg

Mitco39 03-27-2014 09:05 AM

Quote:

Originally Posted by Megan370z (Post 2755025)

Shouldnt the engine have long and short term trims that should handle these inconsistencies?

Megan370z 03-27-2014 11:28 AM

Quote:

Originally Posted by Mitco39 (Post 2755972)
Shouldnt the engine have long and short term trims that should handle these inconsistencies?

you mean he ECU....

short answer yes,
but not all sensors are the same. There is tolerance that are acceptable in everything, OEM included.

I had that type of variance .5 to 1.0afr when I did my custom CAI and I fixed it with tuning.

Mitco39 03-27-2014 11:41 AM

Quote:

Originally Posted by Megan370z (Post 2756187)
you mean he ECU....

short answer yes,
but not all sensors are the same. There is tolerance that are acceptable in everything, OEM included.

I had that type of variance .5 to 1.0afr when I did my custom CAI and I fixed it with tuning.

yes I did mean ECU sorry. Right but my concern would be once you start manually messing with the duty cycle of each cylinder how do you know that say you arent running lean on 2 cylinders and rich on the other one? I mean I guess you dont really know with the trim either, but atleast it is not a static value that you input and the ECU runs with as I would imagine setting the trim manually would be.

I am fairly new to the uprev side of things but I have been tuning engines for 4+ years with EFI Live and that would be one of the concerns I would have with manually setting trim values.

I agree that there is tolerances, its why you will only get rich and lean codes after the engine has exhausted its available trim values, but to me this is exactly what the trims should be doing, making sure each bank is running as closely as possible to the target AFR (whatever it is you are calling for).

Just my thoughts...

Megan370z 03-28-2014 11:43 AM

Quote:

Originally Posted by Mitco39 (Post 2756202)
yes I did mean ECU sorry. Right but my concern would be once you start manually messing with the duty cycle of each cylinder how do you know that say you arent running lean on 2 cylinders and rich on the other one? I mean I guess you dont really know with the trim either, but atleast it is not a static value that you input and the ECU runs with as I would imagine setting the trim manually would be.


Just my thoughts...

just to give a sample example on this issue with Bank 1 & 2 not being equal.

adjust the whole bank that is leaner to the other side.
on the table it would be like
1:100%
2:105%
3:100%
4:105%
5:100%
6:105%


as for tuning for each cylinder.
I cant help you on this. I have a theory but I wont go on that subject.

DOOMMONKEY777 04-23-2014 06:38 PM

Just did this cylinder adjustment to 104.69, A/F ratio is exactly the same, before it was about .50 different, also i can hear the engine running more smooth rather than like a tractor.

Jordo! 04-23-2014 07:05 PM

Yep. There's always potential for some variance between the banks -- not sure if .5 would be considered unusually high deviance tho'.

Can you monitor fuel trims for each bank -- how close are they?

Also, one MAF sensor may need to be cleaned or you could have one extra dirty filter.

DOOMMONKEY777 04-23-2014 07:23 PM

Yeah i thought it was the filters as well so i looked at them they looked barely dirty and i have found a few tree leaves, cleaning that barely did anything. There was notice, but u can still hear that something was off. The A/F logging showed it was off by~-/+.50 from other bank. Found this post and adjusted it, now its right on the money they r both the same ty very much, if it wasn't for this thread and ppl's shearing i don't know when i would have figure it out.:tiphat:


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