Welcome to the North American Subaru Impreza Owners Club Monday February 27, 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 12-20-2007, 12:32 AM   #26
Wheeler Bement
Scooby Specialist
Member#: 15652
Join Date: Feb 2002
Chapter/Region: TXIC
Location: sugar land, katy
2002 2.5L WRX Wag.
160K club


I'll throw this in here just incase someone is struggling with a similar issue.

I had to replace all my boost control hoses because they were hard and cracked. I had done the 3/16 mod years ago, and figured why not make all of it like that(also it was all I had) so I replaced all of the hoses and the little T with 3/16 hose and fittings. Yes, I did put the pill back in the right spot. I am still trying to hammer out the effects of this with my FBC. I have dropped down to 50% Max WGDC and it still overshoots in 3rd. I can hit my max boost of 16.5psi in1st and 2nd, so I know I have a ways to keep going.

maybe I just gave myself more headroom for more boost, ha ha. or I have made the issue impossible and need to replace it with the 1/8" hose and fittings

edit: After struggling for almost two weeks to get the boost set right, and dropping my TDC numbers to almost 20% of the stock values...I gave up and went back to 1/8 hoses. With the smaller TDC numbers, it was close almost spot on when it came to control, but it was over boosting like a mother, and dropping my max WG% early on did nothing but make spool up supper slow. Maybe if I had more time...but I figured two weeks was enough. perhaps I should have gone with bigger numbers...but I found it compouded the problem and the slightest over boost meant a massive dump.
* Registered users of the site do not see these ads.

Last edited by Wheeler Bement; 12-29-2007 at 11:23 PM.
Wheeler Bement is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 12-20-2007, 12:52 AM   #27
Scooby Newbie
Member#: 122595
Join Date: Aug 2006
Chapter/Region: NWIC
2005 LGT Wagon


When tuning boost on a new setup, I do the opposite.

1. First thing I do is set reasonable boost targets. You should have a rough idea based upon other people's performance with your particular turbo. I usually shoot for about 1 psi less than what others have achieved. (Then examing boost plots in 4th gear plus plots of MRP vs load, I adjust the target boost later.)

2. After setting up the boost target, I set up the TD parameters. On a 2 port system, I use a very slightly modified stock TD.

3. Then I set WGDC initial to 0 across the board and I use a very high WGDC max. Datalog from 2000 rpm to redline in all gears and then keep increasing WGDC initial until you hit target boost.

4. Once you can hit target boost, adjust WGDC max so that WGDC max = WGDC init + 10% in the partial throttle region and in the far right column set WGDC max = WGDC init + TD Integral max + 5%. TD integral max is usually 15%.

4a. Make sure that the difference between WGDC init and WGDC max is constant or monotonically decreasing as rpm rises.

5. Adjust boost targets based upon accel and MRP vs load, etc... and redo.

6. Datalog starting from 3000 and/or 4000 rpm in 3rd and 4th gear. Check for spiking. Adjust TD accordingly.
mickeyd2005 is offline   Reply With Quote
Old 12-20-2007, 11:24 PM   #28
Scooby Guru
Member#: 140444
Join Date: Feb 2007
Chapter/Region: NWIC
Location: Near Seattle, WA
05 Stage Free LGT


Great thread, guys.
NSFW is offline   Reply With Quote
Old 05-05-2010, 03:36 PM   #29
Scooby Specialist
Member#: 158579
Join Date: Sep 2007
Chapter/Region: MWSOC
Location: St. Louis
2005 Lotus Elise SC
94 Legacy Rally Car


Bringing up a thread from the dead. But what kind of timing/AFR are you guys using during spool-up?
MConte05 is offline   Reply With Quote
Old 05-19-2014, 10:53 AM   #30
Scooby Newbie
Member#: 259778
Join Date: Oct 2010
Chapter/Region: BAIC
Location: Ithaca, NY
2002 WRX


Back from the dead.

This is a great read. I have been reading all kinds of boost tuning info for the 32-bit ecus which is pretty worthless for a 16-bit.

So for a 16-bit ecu, why would you even set the max WGDC differently on any cell? It seems like you could just pick one number and put that across the board, along with some reasonable boost targets and it would try to hit your boost targets automatically, unlike a 32-bit ecu which has that initial WGDC you have to accurately set to avoid initially over-boosting/under-boosting.

Obviously you want the max WGDC to reflect what it typically takes to reach the target for safety (plus some margin for error). Does anyone just do the following:

1. Set up a reasonable boost target table
2. Set max WGDC to some constant across the board
3. Log to see if target in each cell is reached and if so at what WGDC.
4. Adjust max WGDC up in cells that did not reach target boost, and set it to the WGDC that was required to reach target boost + 10% or so in cells where target was achieved.
5. Repeat 3 and 4 until you get all max WGDC 10% above the max WGDC you observe.
xdeathwishx 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
Question on Boost Targets and Wastegate Duty on initial tune of GT30R roybfr Engine Management & Tuning 0 06-09-2006 06:25 PM
The theory around boost target srf Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo) 1 09-24-2005 02:42 AM
Cobb stage 2... not hitting boost target level... WRXVII Engine Management & Tuning 37 06-06-2004 01:14 AM
What happened to the HiVisibility @ Target thread? NeoteriX Texas Impreza Club Forum -- TXIC 3 03-30-2003 08:04 PM
HEY!!! What happened to the Cobb/Vishnu tuning infor/debate thread!!!! davidm_sh Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 1 07-18-2002 05:18 PM

All times are GMT -4. The time now is 04:01 AM.

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.