Welcome to the North American Subaru Impreza Owners Club Thursday September 18, 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

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 04-01-2005, 10:49 AM   #1
WRXout
Scooby Specialist
 
Member#: 52908
Join Date: Jan 2004
Location: Houston, on highway 6
Vehicle:
2005 WRX STI FTI 20G
ASPEN WHITE

Default perams psi value

is it important to set the psi value in perams? im supposed to be hitting 18 but its set to 20

thank you
WRXout is offline   Reply With Quote
Old 04-01-2005, 11:38 AM   #2
2phless
Scooby Specialist
 
Member#: 69343
Join Date: Aug 2004
Chapter/Region: South East
Location: 'tween Lewisville&Clemmons NC
Vehicle:
1998 TransAm cnvrtbl
Black

Default

UTEC?

If you are set to map to 18 psi ad you hit 20 then you are going way past the 100% column of your maps.
2phless is offline   Reply With Quote
Old 04-01-2005, 02:17 PM   #3
dosage0
Scooby Newbie
 
Member#: 42323
Join Date: Aug 2003
Location: VF35, Pinks
Vehicle:
2004 WRX
Silver - UTEC, Tuna, TBE

Default

you should try to set it correctly. Whatever you set your max psi to is going to effect the amount of fuel (load column) the car puts in. If your max psi is 16 and you are hitting 20, its putting in the same amount of fuel from 16-20 psi... its always going to be in the 100% column. If you set your max psi to 20, when it hits 16, it will be in the 80% load column and use the 80% fuel settings.

Rob
dosage0 is offline   Reply With Quote
Old 04-01-2005, 11:49 PM   #4
x99percent
Scooby Specialist
 
Member#: 27108
Join Date: Oct 2002
Chapter/Region: MWSOC
Location: Detroit-ish, MI
Vehicle:
2004 STi
2004 A4

Default

Quote:
Originally Posted by dosage0
If your max psi is 16 and you are hitting 20, its putting in the same amount of fuel from 16-20 psi...
Quote:
Originally Posted by dosage0
Why could this be a problem? Because if your car is setup to put in the same amount of fuel when you hit 16lbs as when you hit 20lbs, you are obviously going to be much leaner at 20 lbs.
This is false.

If your max mapping parameter is set to 16psi, then the UTEC is applying the same correction factor for >= 16psi of boost.
x99percent is offline   Reply With Quote
Old 04-01-2005, 02:35 PM   #5
WRXout
Scooby Specialist
 
Member#: 52908
Join Date: Jan 2004
Location: Houston, on highway 6
Vehicle:
2005 WRX STI FTI 20G
ASPEN WHITE

Default

so if i change this to like 18, will it effect fuel? retuneing needs to be done? is that what causes knock? and maybe hesitation i get every now and then, but it was tuned liek that wieerd

Last edited by WRXout; 04-01-2005 at 02:42 PM.
WRXout is offline   Reply With Quote
Old 04-01-2005, 03:36 PM   #6
dosage0
Scooby Newbie
 
Member#: 42323
Join Date: Aug 2003
Location: VF35, Pinks
Vehicle:
2004 WRX
Silver - UTEC, Tuna, TBE

Default

Quote:
Originally Posted by WRXout
so if i change this to like 18, will it effect fuel? retuneing needs to be done? is that what causes knock? and maybe hesitation i get every now and then, but it was tuned liek that wieerd
Lots of questions at once.

Heres the big picture. You have columns that tell the car how much fuel to put in. They are done by taking the fuel parameters and dividing. So if you have set 20 psi as your absolute max, at 16psi your car would use the 80% column. 16/20 = 80%.

Just remember that the higher the % column the more fuel is being put in.

Now if your car is constantly hitting 100% load because your max psi is set low -- you arent using the fuel map very well. You should only hit 100% when your psi is maxed. Then the fueling will be maxed (not maxed out meaning dumping stoich... meaning putting in fuel at the highest rate needed). If you are only hitting 80% of what you can in terms of boost, you should only use 80% of that fuel amount.

Get it?

Why could this be a problem? Because if your car is setup to put in the same amount of fuel when you hit 16lbs as when you hit 20lbs, you are obviously going to be much leaner at 20 lbs.

If the car is running alright, then I wouldnt worry about it too much. Its just not tuned well. Its confusing at first, but your boost/timing/fuel maps are all related. Whatever boost you are at is divided by the max boost you set it your params. That gives you a load %. Thats used by the fuel map to determine how much fuel to put in.


Rob
dosage0 is offline   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
Best Min and Max PSI Values for Progressive Boost Controlled Injection klattery Water/Methanol Injection, Nitrous & Intercooler Cooling 4 03-23-2006 01:00 PM
utec, perams question WRXout Engine Management & Tuning 2 03-21-2005 08:03 PM
Utec users... Make sure you have the right perams loaded! AZScoobie Engine Management & Tuning 9 10-25-2004 07:44 AM
How many PSI is too many PSI? virus67 Factory 2.0L Turbo Powertrain 9 07-03-2001 10:39 PM
Bosche BOV leaks over 7 psi, need recs for BOV for 0-12 psi ImprezaRS dot com Factory 2.0L Turbo Powertrain 22 05-10-2001 11:25 PM


All times are GMT -4. The time now is 12:31 AM.


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.