Welcome to the North American Subaru Impreza Owners Club Friday September 19, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
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.
Reply
 
Thread Tools Display Modes
Old 01-24-2008, 05:14 PM   #1
Tea cups
Scooby Specialist
 
Member#: 103136
Join Date: Dec 2005
Default Turbo Dynamics and boost control explained

* Registered users of the site do not see these ads.

Last edited by Tea cups; 10-18-2008 at 03:52 PM.
Tea cups is offline   Reply With Quote
Old 01-24-2008, 05:14 PM   #2
Tea cups
Scooby Specialist
 
Member#: 103136
Join Date: Dec 2005
Default

This was a sticky on the Enginuity site before it went down.
Tea cups is offline   Reply With Quote
Old 01-24-2008, 05:33 PM   #3
Infamous1
Scooby Newbie
 
Member#: 133692
Join Date: Nov 2006
Chapter/Region: SCIC
Location: In So Cal tuning YOU!!! ;)
Vehicle:
2003 Chevy Z06
Black/Black

Default

Thanks!
Infamous1 is offline   Reply With Quote
Old 01-24-2008, 06:44 PM   #4
wrxsti.l
Scooby Specialist
 
Member#: 156973
Join Date: Aug 2007
Chapter/Region: International
Location: Adelaide, Australia
Vehicle:
2002 ADM WRX STi
STi Black/Blue

Default

Cheers for the info Tea Cups.

Do you have any other "stickies" from the Enginuity site that you could post that will help?

--- Start Ignore ---
Also, was there ever a "beginners tuning guide" or similar for Enginuity? Something that shows the steps involved in tuning and what all the features/settings/parameters mean in Enginuity?
---End Ignore ---

My bad, I did some googling and found a link to Scoobypedia's Open ECU Tuning Guide and Documentation Index that has all the info I was after
wrxsti.l is offline   Reply With Quote
Old 01-24-2008, 07:04 PM   #5
ExpO
*** Banned ***
 
Member#: 115819
Join Date: May 2006
Chapter/Region: Tri-State
Location: UDel, illidelphia
Vehicle:
2006 vf39 R0mRa1DeR
Darknessess Wagon

Default

Thanks!

+1 on any good info from enginuity.
ExpO is offline   Reply With Quote
Old 01-24-2008, 07:09 PM   #6
Tea cups
Scooby Specialist
 
Member#: 103136
Join Date: Dec 2005
Default

Quote:
Originally Posted by wrxsti.l View Post
Cheers for the info Tea Cups.

Do you have any other "stickies" from the Enginuity site that you could post that will help?
The only other sticky I had was the "closed loop to open loop transition and delay explained", but I don't have a copy of it and can't find it cached anywhere and I don't want to redo it from scratch as I know it is out there somewhere.
Tea cups is offline   Reply With Quote
Old 01-24-2008, 10:35 PM   #7
mickeyd2005
Scooby Newbie
 
Member#: 122595
Join Date: Aug 2006
Chapter/Region: NWIC
Vehicle:
2005 LGT Wagon
ABP

Default

I hope someone stickies this thread. This is the best description of Subaru boost control that I have found. It is a closed loop (feedback) system. Check out Proportional Integral Derivative controller in wikipedia.org.

http://en.wikipedia.org/wiki/PID_controller

Many of the tunes that I have seen block out the turbodynamics so that boost is controlled strictly by either minimum or maximum WGDC. The problem with this is that boost is then only controlled for one type of driving (e.g., 3rd gear from 2000 to redline). If you drive in any other way (different gear or start from a different rpm), you will either underboost or overboost.

Take a look at this PID feedback example:



And compare that to what happens when overboosting occurs in 5th gear and underboosting in 2nd gear.

The best way to learn more about turbodynamics is to log TD Integral and TD proportional and log all kinds of driving:

1. 2nd gear from 2000 to redline
2. 3rd gear from 2000 to redline
3. 4th gear from 2000 to 4000 rpm
4. 5th gear from 2000 to 3500 rpm (only if your intake doesn't resonate)
5. 3rd gear from 3000 rpm to redline
6. 4th gear from 2500 rpm to 4000 rpm
7. 2nd gear to 6500 rpm and then shift to 3rd and continue WOT

You will see that the WGDC needed to hit target boost varies depending upon time (related to load) and previous boost state.
mickeyd2005 is offline   Reply With Quote
Old 01-25-2008, 10:36 AM   #8
legav05
Scooby Newbie
 
Member#: 51287
Join Date: Dec 2003
Chapter/Region: NESIC
Vehicle:
2005

Default

What happens if your intake resonates?
legav05 is offline   Reply With Quote
Old 01-25-2008, 11:41 AM   #9
mickeyd2005
Scooby Newbie
 
Member#: 122595
Join Date: Aug 2006
Chapter/Region: NWIC
Vehicle:
2005 LGT Wagon
ABP

Default

That's kind of off-topic, but it can cause knock due to the air surging which causes momentary lean spikes.

I have seen it in 5th gear at 18 psi at 2700 rpm with the LGT K&N intake and I have also seen it happen in 4th gear at a much lower psi with the SPT intake at about 2500 rpm. I's not a problem for big turbos since they don't build up that much boost at low rpm.
mickeyd2005 is offline   Reply With Quote
Old 03-27-2008, 03:43 PM   #10
Bad Noodle
Scooby Specialist
 
Member#: 174442
Join Date: Mar 2008
Chapter/Region: Tri-State
Location: NNJ
Vehicle:
2007 SuperWagon
I don't spell well

Default

One thing I don't understand is what is your final wastegat duty cycle?

In other words
How is the final wastegate duty being apply to the car calculated from
Intial Wastegate Duty
Max wastegate duty
Compensations
TD proportional
TD Intergral + / -

?

Thanks
Bad Noodle is online now   Reply With Quote
Old 03-27-2008, 07:44 PM   #11
Tea cups
Scooby Specialist
 
Member#: 103136
Join Date: Dec 2005
Default

Quote:
Originally Posted by Bad Noodle View Post
One thing I don't understand is what is your final wastegat duty cycle?

In other words
How is the final wastegate duty being apply to the car calculated from
Intial Wastegate Duty
Max wastegate duty
Compensations
TD proportional
TD Intergral + / -

?

Thanks
The wg compensations are applied to both initial and max wgd (they are relative, so 10% compensation of 50% WGD = 55% WGD). However, TD correction is absolute.

x = initial wgd (post-comp) + TD prop + TD integral cumulative
if x > max wgd (post-comp) then x = max wgd
if x > "Wastegate Duty Limit (Maximum)" then x = "Wastegate Duty Limit (Maximum)

final wgd = x
Tea cups is offline   Reply With Quote
Old 03-27-2008, 08:15 PM   #12
Bad Noodle
Scooby Specialist
 
Member#: 174442
Join Date: Mar 2008
Chapter/Region: Tri-State
Location: NNJ
Vehicle:
2007 SuperWagon
I don't spell well

Default

^ thanks man, you rock
Bad Noodle is online now   Reply With Quote
Reply

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
Anyone have a nice clean way to mount a greddy turbo timer and boost controller? Cards2323 Interior & Exterior Modification 14 05-16-2007 11:28 AM
Turbo Inlet and Boost Controller Lines 02 WRX MyMY02WRX Private 'Wanted' Classifieds 2 09-01-2006 11:44 AM
GREDDY turbo time and boost controller for sale!! HighEndWRX Private 'For Sale' Classifieds 1 02-06-2004 12:22 PM
turbo timer and boost controller instal wrxnut Factory 2.0L Turbo Powertrain 1 11-09-2003 06:09 PM
Turbo timer and boost controller questions yeloREX Factory 2.0L Turbo Powertrain 1 10-19-2001 11:41 PM


All times are GMT -4. The time now is 11:04 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.