[JohnSub2013sti]

Thank you for the reply. So you would expect this behavior from an unscaled Maf when looking at total correction ?

Do you have a good reference to read regarding finding the correct final correction?

My expectation for the change in flow rate with a cold air intake was that it would read lean across the board
Since Mafs measure the rate of cooling to operate...

These would be my initial corrections. I just didn't think they would be this large..... It almost makes me want to check for vacuum leaks

 

[JohnSub2013sti]

Does anyone have input on this? I'm worried this is mechanical as opposed to a tunning problem
Maybe someone could post the change in there maf scaling with a cold air intake (I know it won't be exactly the same)

Also feel free to call me out if I'm being stupid about something

Edit here's a random stage 2 map comparison i found online

 

[JohnSub2013sti]

Thank you this makes complete sense.... and is what I would expect.

But if this is how it works then why am I getting both negative and positive afr learning

The method you described would mean a cold air intake leans the engine out for the complete table

Unless I'm mistaken

Sent from my SM-S901W using Tapatalk

 

[JohnSub2013sti]

This is what I've changed for now

at least my AFR wont be off under 50g/s

 

[JohnSub2013sti]

Ya i'll do that... This might be a stupid question but

How would I scale the maf beyond 60 g/s (transition from closed loop to open loop fueling).
Do i just use the interpolation curve ?

 

[JohnSub2013sti]

Do you have a recommendation on a wide band with maximum accuracy ?

I found a Prosport kit that would be nice. I also see a lot of people using AEM. I assume you would reccomend COBB though ?

 

[JohnSub2013sti]

Thanks man you've been a big help.

I was going to do some calculations on open loop MAF scaling (with my stock sensor). I have a 32-bit ECU where the O2 sensor works over a wider range but is skewed due to it being in the front exhaust pipe (exaughst back pressure). I wanted to do this just to learn a bit and see how off the values would be

I was using this guide as a reference
HOWTO: One Man's Way of Scaling a MAF - NASIOC

....
but then I realized I don't even understand how the AFR Correction 1 is calculated in closed loop
I figured it would be

A/F Sensor #1 / (1 - A/F Correction #1 * 100) = Closed Loop Fueling Target

But that doesn't seem to work.... do you know how its calculated

Sorry for all the questions lol

 

[JohnSub2013sti]

Thanks again! I have one final question

A/F Correction #1 (%) & AF Learning 1 are closed loop short term and long-term fueling corrections in closed loop, right?
Subaru Monitor List - Customer Support Center - Confluence (atlassian.net)
But what would the right parameters be in open loop?

 

[JohnSub2013sti]

Thats what i thought.... But this utility here (designed for maf scaling)
RomRaider • View topic - UTILITY: CL/WOT MAF Scaling | Log View/Stats | Load/IAT Comp

Accept fuel trims in both Open Loop and Closed Loop....
And it was made for Subarus... which has me confused

Open Loop

Close Loop

Edit: I also ordered a AEM wideband

 

[JohnSub2013sti]

I have my wide band installed now. Would good practice be to decrease the AFR across the board before trying to tune open loop.

Just to be safe and have lots of fuel (preventing lean conditions)

eg reducing every cell in the primary open loop fueling table by -0.5

 

[JohnSub2013sti]

That makes sense, I considered doing that instead.

Is there something negative about temporarily changing the open loop fuel table, though?



Sent from my SM-S901W using Tapatalk

 

[JohnSub2013sti]

Would you not do that because too rich conditions can cause knock too and also afr is directly tied to timing ?

Sent from my SM-S901W using Tapatalk