MAF Scaling - Open/Closed Loop Fueling info

[Jyn]

Sorry to bring up an older thread. I saw some recommendations that TRD intake doesn't need to be scaled, but looking through some logs I have from today, I see about 8-10% on LTFT in some cruising data. The interesting part is that my WOT 3rd gear pull is 0% LTFT.

Is this something that needs to be corrected via MAF scaling, or is that to be expected from TRD intake + full UEL header-back exhaust?

[steve99]

Originally Posted by Jyn

Sorry to bring up an older thread. I saw some recommendations that TRD intake doesn't need to be scaled, but looking through some logs I have from today, I see about 8-10% on LTFT in some cruising data. The interesting part is that my WOT 3rd gear pull is 0% LTFT.

Is this something that needs to be corrected via MAF scaling, or is that to be expected from TRD intake + full UEL header-back exhaust?

The TRD intake wont cause the maf scaling to change but its not unusual for stock maf scaling to be out by 8% or so in places even with stock intake.

So maf scaling is usually beneficial even with stock intake.

Some aftermarket intakes will see ltft of 15 to 20% thats when your rearly must rescale.

[eddieflyinv]

http://datazap.me/u/eddieflyinv/perr...=0&data=3-4-10

this is the 5th log after installing perrin 3inch intake, with their supplied maf scale... worst anyone has ever seen??
i figured id give it some time to learn after watching the first logs numbers creep up, but it just got worse and worse,
mods on car are crawford bpb, tanabe catless fp (possible its leaking ? did some reading and this crazy of ltft can be caused by that ?) and a catback,

any pros out there care to share if they think its a tune issue or hardware problem? hadnt noticed any leaks in the exhaust, and i was pretty thorough with the intake install, everything was tight and secure, so yeah, is the perrin scaling really this bad ???

[steve99]

Originally Posted by eddieflyinv

http://datazap.me/u/eddieflyinv/perr...=0&data=3-4-10

this is the 5th log after installing perrin 3inch intake, with their supplied maf scale... worst anyone has ever seen??
i figured id give it some time to learn after watching the first logs numbers creep up, but it just got worse and worse,
mods on car are crawford bpb, tanabe catless fp (possible its leaking ? did some reading and this crazy of ltft can be caused by that ?) and a catback,

any pros out there care to share if they think its a tune issue or hardware problem? hadnt noticed any leaks in the exhaust, and i was pretty thorough with the intake install, everything was tight and secure, so yeah, is the perrin scaling really this bad ???

1. The perrin supplied scaling is not very good in car I tried it on

2. you rearly do need to make sure you have no intake or exhaust leaks else this will cause high LTFT, exhaust leaks usually give you high positive trims at lower, which you dont have.

you either need to rescale maf yourself see links at bottom or

I suggest you try @Wayno s3" maf scaling, knowing wayno it will be pretty good.

Make sure you use the 3" perrin if you have that , the spreadsheet below has both 2.75 and 3

whole thread here http://www.ft86club.com/forums/showthread.php?t=94822

direct link to maf scalings
https://docs.google.com/spreadsheets...-UL7XLR3Y/edit

[eddieflyinv]

@steve99 thanks for the advice and the links.
I have been using Waynos 3" Perrin MAF scale for a week now and my numbers aren't looking that much better for LTFT
I want to start scaling the MAF myself but it's like -18°C outside right now and I have seen multiple recommendations of doing scaling when its 20-25°C..
What I'm thinking is if I flatten the IAT Compensation tables can I effectively do the scaling now? Or am I wasting my efforts considering how cold it is. I would rather not reinstall the OEM intake. And really hope I don't have to wait till it warms up to do this as I am still seeing up to -20% at times and it bothers me a lot.
Thanks in advance,

Sent from my LG-H812 using Tapatalk

[jprice130]

Been trying to dial in my MAF scale and the last two tunes I flashed are producing 0 LTFT in both closed loop and open loop. This has remained for 50+ miles after flashing. I am seeing various STFT values in my logs but LTFT is pegged at zero no matter what. I'm fairly certain my MAF scale is not that perfect (ha, ha), so is there something I'm missing that would cause this?

[Wayno]

Originally Posted by eddieflyinv

@steve99 thanks for the advice and the links.
I have been using Waynos 3" Perrin MAF scale for a week now and my numbers aren't looking that much better for LTFT
I want to start scaling the MAF myself but it's like -18°C outside right now and I have seen multiple recommendations of doing scaling when its 20-25°C..
What I'm thinking is if I flatten the IAT Compensation tables can I effectively do the scaling now? Or am I wasting my efforts considering how cold it is. I would rather not reinstall the OEM intake. And really hope I don't have to wait till it warms up to do this as I am still seeing up to -20% at times and it bothers me a lot.
Thanks in advance,

Sent from my LG-H812 using Tapatalk

I've never worked on any 3" perrin.

[phrosty]

Originally Posted by eddieflyinv

...can I effectively do the scaling now?

If you scale your MAF now, the values will be valid for your current temps. You'll just have to redo it later on when it warms up. If you're seeing -20%, I'd definitely do it now assuming you've checked for leaks already.

[jvincent]

Originally Posted by eddieflyinv

What I'm thinking is if I flatten the IAT Compensation tables can I effectively do the scaling now? Or am I wasting my efforts considering how cold it is.

Unfortunately the way the IAT temperature compensation table is defined makes it pretty much useless for any kind of fine grained control.

I don't have it in front of me fright now but IIRC the table supports an adjustment range of +/- 50% in 4% increments from the baseline of 68* F.

The problem is that for the temperature ranges we actually see you need a much smaller adjustment range but the table won't let you do it properly.

[eddieflyinv]

Originally Posted by Wayno

I've never worked on any 3" perrin.

Huh.. There was a 3" perrin scale in whatever link @steve99 directed me too, that was different from the Perrin supplied MAF. No big deal though, i went ahead and did my own scaling, I was worried about the temps throwing things off but im within about 3% +/- and as the temps have been rising its getting better, so it all worked out anyways

Sent from my LG-H812 using Tapatalk

[jprice130]

Originally Posted by jprice130

Been trying to dial in my MAF scale and the last two tunes I flashed are producing 0 LTFT in both closed loop and open loop. This has remained for 50+ miles after flashing. I am seeing various STFT values in my logs but LTFT is pegged at zero no matter what. I'm fairly certain my MAF scale is not that perfect (ha, ha), so is there something I'm missing that would cause this?

I'm now 100+ miles since my last flash and I'm still getting 0 LTFT. I ran a log with mostly closed loop driving for 20 minutes and LTFT was zero the entire time. Has anyone else ever experienced this? I've been logging with the Tactrix OP2 and I haven't changed my logcfg.txt file in over a year. All other parameters log as expected.

[cawith]

Hi,

So I decided to try scale my closed loop as well now, but I'm not sure about all the settings when loading logs.

Do the ones shown in the screenshot look alright? I don't know why the MAF Voltage Maximum is 32, it was supposed to be 3.2V.

Also, at idle the engine load is below the minimum of 0.2. Should I lower that minimum, so that it counts the idle cells in as well, or is it better to leave that out?

Thanks!

[steve99]

Originally Posted by cawith

Hi,

So I decided to try scale my closed loop as well now, but I'm not sure about all the settings when loading logs.

Do the ones shown in the screenshot look alright? I don't know why the MAF Voltage Maximum is 32, it was supposed to be 3.2V.

Also, at idle the engine load is below the minimum of 0.2. Should I lower that minimum, so that it counts the idle cells in as well, or is it better to leave that out?

Thanks!

yes change the ol/cl voltage to 3.2 not 32


the min load is probably ok at 0.2 but you could try 0.1

[freerunner]

Originally Posted by cawith

Do the ones shown in the screenshot look alright? I don't know why the MAF Voltage Maximum is 32, it was supposed to be 3.2V.

Yeah, it's a bug in vgitool for everyone whose system locale is not English.

If you want to keep your currently used system locale settings, you can use per-app locale setting as a workaround:

Edit your run.bat. After javaw.exe add two variables:

-Duser.language=en -Duser.country=us

If you're using Romraider, you'll want to run it like that, too. Else you might not be able to copy&paste table values.