Welcome to the North American Subaru Impreza Owners Club Monday January 22, 2018
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Technical > Engine Management & Tuning > Open Source 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
Prev Previous Post   Next Post Next
Old 01-01-2012, 07:24 PM   #1
Scooby Specialist
Member#: 53665
Join Date: Jan 2004
Chapter/Region: NESIC
Location: Northboro, MA
2011 STI Stg2 w/ ELH
Focal 2way Active w/ DSP

Default Tuning DBW on '11 STI

I am getting back into tuning on my '11 STI. All of my previous experience comes from tuning 16bit WRXs so my STI is a significant step up in complexity. I am starting with DBW tuning just so that I can get a grip on how it works and be a prelude to boost control and AVCS. What I am looking for is feedback on the approach I am taking with DBW tables. See below.

I've spent a few hours combing through the forums and absorbing the info. From what I can tell, there really isn't much info on how to effectively tune DBW on CAN based STIs that come with 3 major tables (instead of 2 on previous years):

- Requested Torque
- Requested Torque Base
- Target Throttle Plate Position

The new complexity is the base table that is used as a divider to calculate a ratio which is than used in the target table to establish the target throttle opening, formula:

requested torque / torque base value = target throttle ratio

My initial reaction is that it is difficult to get a grip on how the changes in each table will affect the behavior of the car. So, I started to ponder if there is a way make this a bit easier and I came up an approach but I'd like to hear people's feedback on this.

1. Stock requested torque table makes little sense to me, in practical terms, since the settings change with RPM. As a driver, I know what I want at any given time so I'd rather see the table work as a constant value for a given throttle input for all RPMs. Below is a first stab at this (sport # mode) where I scaled the table in linear fashion: 25% throttle means 25% requested torque, 50% throttle means 50% requested torque, etc etc. Note the max value of 450.

2. Now, what about this divider base value? The approach that I took is to set the entire table to my max value in requested torque table (450). What that does effectively is that every value in the requested torque table will be divided by the max thus making the calculated ratio become the percentage of the requested torque, for any RPM. For example, 300 / 450 becomes 0.67 which is 67% of the max value. At least for me, this gives me an easy mental picture on what the ratio values mean in the next table.

3. Lastly, I rescaled the target throttle table in a linear fashion, similar to what I did in requested torque table. Since the ratio is now the percentage of requested torque, it's easy to anticipate what the values will lead to when the ECU dials in the throttle position. Again, this is a first shot and I don't know what these settings will 'feel' like when I drive the car. But, this helps me in wrapping my mind around this triple table concoction.

What are your thoughts on this? Please post your feedback and let me know if this makes sense. I will try this on the car and see what the settings feel like. I will likely end up making adjustments in requested torque table as this will play nicely into the boost control system adjustments. For example, I am end up upping some RT values which will yield a higher ratio and end up with higher throttle target in relation to the actual throttle input. We'll see how this goes.
Ziggyrama 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
WTB/WTT : DGM '11 STi wing for wrx trunk. (NJ) STiSteeze Private 'Wanted' Classifieds 1 02-02-2012 08:26 PM
are struts on '11 Outback same as what's on an '11 Legacy bradze Legacy Forum 2 12-20-2011 02:49 PM
18x9.5 et45 TRMotorsports MT1 wheels on '11 STI Sedan scooby24 Tire & Wheel 11 11-27-2011 11:14 AM
Question Regarding COBB and Stage 1 results on '11 STI DiOdE_EE AccessPort 2 05-05-2011 02:24 PM
SPT cat-back exhaust on '11 STI wholmesb Newbies & FAQs 5 12-20-2010 06:18 PM

All times are GMT -4. The time now is 04:15 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2018 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.