Welcome to the North American Subaru Impreza Owners Club Monday December 11, 2017
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Technical > Engine Management & Tuning

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads. 
Thread Tools Display Modes
Old 06-06-2005, 03:59 PM   #1
Scooby Specialist
Member#: 84313
Join Date: Apr 2005
Chapter/Region: NWIC
Location: Boise, ID
04 Aspen STi

Default a/f learning and maf scaling

i just installed my perrin fmic and perrin big maf system.

and i got the a/f correction down to .78 at idle, but when im driving it climbs to 14.84 (i assume that is maxed out) then falls to around 7 or so when i go wot in the higher rpm's which is once it is out of closed loop. does this mean that i need to adjust the maf calibration more?? i have read that a af correction will bounce around alot when the maf is too low, but how do you know when you have gone too far in increasing the maf scaling?

i am using cobb street tuner
* Registered users of the site do not see these ads.
deluxsti is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 06-06-2005, 04:46 PM   #2
Scooby Specialist
Member#: 75122
Join Date: Nov 2004
Chapter/Region: SCIC
Location: Im in a glass case of emotion
2005 Impreza WRX
Crystal Gray


AF correction will bounce around when you accelerating and decelerating. Try to keep it at a constant load and a constant RPM when tuning the MAF. If your going uphill and then downhill, readings will be off.
darksands is offline   Reply With Quote
Old 06-06-2005, 05:22 PM   #3
Scooby Specialist
Member#: 27108
Join Date: Oct 2002
Chapter/Region: MWSOC
Location: Detroit-ish, MI
2004 STi
2004 A4


I have no experience with the ST software, but here's my guess, based on BigMAF experience with the UTEC:

Use the scaling to get things close (small A/F corrections) while at a cruise, and then make adjustments to the fuel map to make things proper at idle.
x99percent is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Turbo Swap and MAF Scaling scramjett Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo) 3 03-01-2010 11:42 AM
Maf scaling - need to be done with stock intake and injectors? Shadoxity Open Source Reflashes 10 05-03-2009 08:35 PM
Knocking on throttle down and lift after MAF scaling Fongers Open Source Reflashes 2 01-04-2009 07:17 PM
maf scaling and ecu definitions rebizap Commercial ECU Reflashes 2 10-31-2007 04:31 AM
Injector and MAF Scaling xolosis UTEC 3 10-07-2006 06:06 AM

All times are GMT -4. The time now is 04:34 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2017 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.