Welcome to the North American Subaru Impreza Owners Club Saturday September 23, 2017
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Technical > Engine Management & Tuning > Commercial ECU Reflashes

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 08-28-2007, 10:15 AM   #1
Scooby Specialist
Member#: 141590
Join Date: Feb 2007
Chapter/Region: TXIC
Location: Clear Lake, Texas
2010 Silverado
2007 CRF250R

Default Correcting an intermittant knock condition...

Okay - the basics - 2006 STi, APS catted TBE, K&N drop in filter, trimmed stock heat shield, XPT Stage two map.

I logged the heck out of it when i had no cat and the stock filter and never got a lick of feedback KC, but after installing the cat & KN filter and resetting the ECU (removed neg batt cable for 10 mins and pumped brakes a bunch) , on occasion I get a knock sensor that get triggered and it will pull -2 degrees then feed it back almost immediatly. Once or twice right after reset it pulled -4 deg but never more than that. THE PROBLEM IS NOT CONSISTANT though...sometimes yes sometimes no. It is not gear dependant, as it does it sometimes in 3-5 and other times in those same gears - nothing. Always WOT from 2K-6.3K ish, except 5th i dont want to lug it that badly...

I have heard for instance that bumpy roads can lead to false knock event detection, and the roads here are bumpy, but not too bad... It seems pretty consistant in the 34-35K rpm range, but is gone by 36-37K rpm.

My question is how much timing should I remove from the map? Is half degree steps going to be safe, or should i try lower ?

Also just a general question - how does Knock differ from Detonation? I had always kind thought they were the same thing...

I'm aware that this thread is pretty useless without logs and will put them up later tonight, but i am paraniod and worried about the car, so any pre-advice before i get them up would be greatly appreciated.
* Registered users of the site do not see these ads.
joe-6STi is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 08-28-2007, 12:26 PM   #2
Scooby Specialist
Member#: 44422
Join Date: Sep 2003
Chapter/Region: SWIC
Location: Gilbert, AZ
2009 G8 GT
Cammed, sprayed, stalled


Look at your intake air temps. Higher intake air temps increase the likely hood of knock. I suggest looking at the intake air compensation table for ignition timing and using that to reduce the timing.

Also, increased exhaust backpressure (by adding a cat) will also increase likelyhoold of knock.

Plus the XPT maps have very aggressive timing to start with.
blkscooby 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
How come I Can't see feedback knock correction, fine learning knock correction? AraSh Open Source Reflashes 23 01-08-2014 07:04 PM
How to get rid of random/intermittent knock? Phatron Commercial ECU Reflashes 18 11-19-2007 05:53 PM
intermittent air conditioning noise? CletusTheDwarf Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 6 07-14-2005 11:10 AM
what do most tuners do to correct a slight knock right before turbo hits full boost? blackie Engine Management & Tuning 17 11-26-2004 01:48 PM
Correction of MBC Rich Condition wigglesxjr Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 6 07-08-2001 03:07 PM

All times are GMT -4. The time now is 01:28 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.