Welcome to the North American Subaru Impreza Owners Club Monday July 28, 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 01-28-2008, 03:59 PM   #1
methaddict
Scooby Specialist
 
Member#: 159738
Join Date: Sep 2007
Chapter/Region: SCIC
Location: Socal
Vehicle:
2004 WRB STi
Full Race TS, BW 8374 EFR

Default Perrin modified sti sidefeed latency values on Enginuity?

Anyone know what the latency values are for the Perrin modified 816cc sti yellow sidefeed injectors? I'll be using Enginuity to reflash the latency values. Thanks in advance.
* Registered users of the site do not see these ads.
methaddict is offline   Reply With Quote
Old 01-28-2008, 04:06 PM   #2
06rexwagon
Scooby Specialist
 
Member#: 114730
Join Date: May 2006
Chapter/Region: SWIC
Location: Albuquerque, NM
Vehicle:
2006 WRX Limited Wag
9.9@142

Default

They claim that they're stock, but they are not. I have found this to work:

Code:
6.00	9.00	12.00	14.00	16.00
5.40	1.89	0.97	0.74	0.53
06rexwagon is offline   Reply With Quote
Old 01-29-2008, 01:56 PM   #3
wittmer25
Scooby Newbie
 
Member#: 102970
Join Date: Dec 2005
Chapter/Region: TXIC
Location: Waco, TX
Vehicle:
2004 STi gt30r
Black

Default

What about the injector scalar?
wittmer25 is offline   Reply With Quote
Old 01-29-2008, 03:12 PM   #4
06rexwagon
Scooby Specialist
 
Member#: 114730
Join Date: May 2006
Chapter/Region: SWIC
Location: Albuquerque, NM
Vehicle:
2006 WRX Limited Wag
9.9@142

Default

816cc
06rexwagon is offline   Reply With Quote
Old 01-29-2008, 04:06 PM   #5
wittmer25
Scooby Newbie
 
Member#: 102970
Join Date: Dec 2005
Chapter/Region: TXIC
Location: Waco, TX
Vehicle:
2004 STi gt30r
Black

Default

I was just wandering because the stock sti injector scalar value is less than the rated flow. I have always heard that most people use less than 100% of the rated flow for their injector scalars.
wittmer25 is offline   Reply With Quote
Old 01-29-2008, 05:19 PM   #6
Jon [in CT]
*** Banned ***
 
Member#: 2992
Join Date: Nov 2000
Chapter/Region: NESIC
Location: Connecticut, USA
Vehicle:
02 WRX Sedan
Silver

Default

Quote:
Originally Posted by wittmer25 View Post
I was just wandering because the stock sti injector scalar value is less than the rated flow.
Do you have Denso spec sheets for the stock STI injectors? How did you determine their "rated" flow?
Jon [in CT] is offline   Reply With Quote
Old 01-30-2008, 06:38 PM   #7
wittmer25
Scooby Newbie
 
Member#: 102970
Join Date: Dec 2005
Chapter/Region: TXIC
Location: Waco, TX
Vehicle:
2004 STi gt30r
Black

Default

I thought everyone knew their "rated" flow. Correct me if I am wrong, but aren't they rated at like 550 cc/min? The stock scalar is closer to 500 cc/min...I can't remember the stock value exactly.
wittmer25 is offline   Reply With Quote
Old 01-30-2008, 07:27 PM   #8
R4ND0M_AX3
Scooby Newbie
 
Member#: 67483
Join Date: Aug 2004
Location: Sacramento, CA
Vehicle:
2005 WRX STi

Default

Stock STi sidefeed injectors are close to 500cc/min.
R4ND0M_AX3 is offline   Reply With Quote
Old 01-30-2008, 10:07 PM   #9
mickeyd2005
Scooby Newbie
 
Member#: 122595
Join Date: Aug 2006
Chapter/Region: NWIC
Vehicle:
2005 LGT Wagon
ABP

Default

One person I know had his sidefeed injectors tested and they are close to 520 cc/min. The 2005 LGT side feed injectors are the same as the 2005 STi side feed injectors. This has been confirmed by part numbers. I'm not sure why enginuity reports one as 500 and the other as 520.
mickeyd2005 is offline   Reply With Quote
Old 01-31-2008, 07:28 PM   #10
Freon
Scooby Specialist
 
Member#: 88322
Join Date: Jun 2005
Chapter/Region: MWSOC
Location: Indianapolis, IN
Vehicle:
2009 BMW 135i

Default

I'm using stock latency values for modified STI side feeds.
Freon is offline   Reply With Quote
Old 01-31-2008, 07:38 PM   #11
06rexwagon
Scooby Specialist
 
Member#: 114730
Join Date: May 2006
Chapter/Region: SWIC
Location: Albuquerque, NM
Vehicle:
2006 WRX Limited Wag
9.9@142

Default

Quote:
Originally Posted by Freon View Post
I'm using stock latency values for modified STI side feeds.
Stock maf scaling? If you want to leave the maf alone you have to change the latency.
06rexwagon is offline   Reply With Quote
Old 01-31-2008, 07:55 PM   #12
Freon
Scooby Specialist
 
Member#: 88322
Join Date: Jun 2005
Chapter/Region: MWSOC
Location: Indianapolis, IN
Vehicle:
2009 BMW 135i

Default

When I changed injectors I made no other changes to my car. I only changed the injector scalar. I never would have been able to tell.

I had bumped the injector latency up to help with the ... less than optimal Perrin GT rotated intake system. But I'm back to stock now with SD.
Freon is offline   Reply With Quote
Old 02-01-2008, 12:19 AM   #13
wittmer25
Scooby Newbie
 
Member#: 102970
Join Date: Dec 2005
Chapter/Region: TXIC
Location: Waco, TX
Vehicle:
2004 STi gt30r
Black

Default

I too run stock latency with good results. My scalar is set at 800.
wittmer25 is offline   Reply With Quote
Old 02-01-2008, 10:18 AM   #14
06rexwagon
Scooby Specialist
 
Member#: 114730
Join Date: May 2006
Chapter/Region: SWIC
Location: Albuquerque, NM
Vehicle:
2006 WRX Limited Wag
9.9@142

Default

Quote:
Originally Posted by wittmer25 View Post
I too run stock latency with good results. My scalar is set at 800.
I've yet to see an STi with a stock maf, running stock maf scaling, and 816cc injectors run stock latency without very large fuel trims at idle.
06rexwagon is offline   Reply With Quote
Old 02-01-2008, 11:04 AM   #15
wittmer25
Scooby Newbie
 
Member#: 102970
Join Date: Dec 2005
Chapter/Region: TXIC
Location: Waco, TX
Vehicle:
2004 STi gt30r
Black

Default

My MAF isn't stock (BigMaf) and I have a ton of other mods and my car idles at 1000 rpms.
wittmer25 is offline   Reply With Quote
Old 02-01-2008, 11:07 AM   #16
06rexwagon
Scooby Specialist
 
Member#: 114730
Join Date: May 2006
Chapter/Region: SWIC
Location: Albuquerque, NM
Vehicle:
2006 WRX Limited Wag
9.9@142

Default

Exactly. You had to scale the MAF so that it would idle anyway because of the BigMAF. It's two ways of achieving the same result. We're both right.
06rexwagon is offline   Reply With Quote
Old 02-02-2008, 10:47 PM   #17
methaddict
Scooby Specialist
 
Member#: 159738
Join Date: Sep 2007
Chapter/Region: SCIC
Location: Socal
Vehicle:
2004 WRB STi
Full Race TS, BW 8374 EFR

Default

Quote:
Originally Posted by wittmer25 View Post
I too run stock latency with good results. My scalar is set at 800.
I'm using Utec but need to change the latency on my ecu in close loop with enginuity. I've had the Perrin modifieds in there before with a protune but I was getting misfire cels so I put the stockers back in. I'm maxing out the stockers right now with meth injection. Just waiting for my Tactrix cable so I'm not familiar with enginuity yet. Is the "scalar" injector scaling?
methaddict is offline   Reply With Quote
Old 02-03-2008, 11:15 PM   #18
bboy
Scooby Specialist
 
Member#: 56468
Join Date: Mar 2004
Chapter/Region: NWIC
Location: Seattle, WA
Vehicle:
04 Improved STI
Dirty White

Default

Latency is just added to the pulse width so you either tune that in the MAF or the scaling. I see no reason to mess with latency. I've used 750 and 775 as the scaler for the Perrin or Kito Auto Sport mod'd sidefeed 820 cc/min injectors.
bboy is offline   Reply With Quote
Old 02-03-2008, 11:42 PM   #19
mickeyd2005
Scooby Newbie
 
Member#: 122595
Join Date: Aug 2006
Chapter/Region: NWIC
Vehicle:
2005 LGT Wagon
ABP

Default

You're better off putting the correct latency in.

6000 rpm at 0.3 g/rev has the same amount of latency as 2000 rpm at 0.3 g/rev but it has 3X the MAF.

If you don't use the correct latency, then you're going to need to tweak every open loop cell especially the low load regions. The high load regions, of course, the latency has negligibl impact. The closed loop will be taken care of by STFT. If you're running speed density, this isn't a problem.

Besides, it is very easy to calculate the latency using a scatter plot or even a consistent high speed idle so I see no reason not to tune the latency correctly.
mickeyd2005 is offline   Reply With Quote
Old 02-04-2008, 12:15 AM   #20
R4ND0M_AX3
Scooby Newbie
 
Member#: 67483
Join Date: Aug 2004
Location: Sacramento, CA
Vehicle:
2005 WRX STi

Default

correcting latency error with the MAF table is also not going to help you when your voltage swings. I've driven cars without functioning alternators before and would hate to have the car just stall immediately because the voltage continued to drop as the battery drained.
R4ND0M_AX3 is offline   Reply With Quote
Old 02-04-2008, 01:00 PM   #21
06rexwagon
Scooby Specialist
 
Member#: 114730
Join Date: May 2006
Chapter/Region: SWIC
Location: Albuquerque, NM
Vehicle:
2006 WRX Limited Wag
9.9@142

Default

Quote:
Originally Posted by mickeyd2005 View Post
You're better off putting the correct latency in.

6000 rpm at 0.3 g/rev has the same amount of latency as 2000 rpm at 0.3 g/rev but it has 3X the MAF.

If you don't use the correct latency, then you're going to need to tweak every open loop cell especially the low load regions. The high load regions, of course, the latency has negligibl impact. The closed loop will be taken care of by STFT. If you're running speed density, this isn't a problem.

Besides, it is very easy to calculate the latency using a scatter plot or even a consistent high speed idle so I see no reason not to tune the latency correctly.
Well said. Funny how me trying to help the OP turned into a debate.
06rexwagon is offline   Reply With Quote
Old 02-19-2008, 08:08 AM   #22
methaddict
Scooby Specialist
 
Member#: 159738
Join Date: Sep 2007
Chapter/Region: SCIC
Location: Socal
Vehicle:
2004 WRB STi
Full Race TS, BW 8374 EFR

Default

I installed the Perrin modifieds in and set the injector scaling to 816cc by using Ecuflash. It was running extremly rich at idle, stumbling and barely idling, eventually stalling. WB afr's where between 22-23 @ idle. I left the latency numbers same as stock since it showed the same on Cobb's info sheet. At some point I also got a 2109 cel. What am I doing wrong?
methaddict is offline   Reply With Quote
Old 02-19-2008, 08:14 AM   #23
06rexwagon
Scooby Specialist
 
Member#: 114730
Join Date: May 2006
Chapter/Region: SWIC
Location: Albuquerque, NM
Vehicle:
2006 WRX Limited Wag
9.9@142

Default

Try the latency values I listed early in the thread. If that doesn't work you have an injector that is stuck. I just had this happen on a car with newly installed 816s. #4 injector wasn't firing and my a/f corrections were ridiculous. I got a misfire CEL.
06rexwagon is offline   Reply With Quote
Old 02-19-2008, 08:36 AM   #24
methaddict
Scooby Specialist
 
Member#: 159738
Join Date: Sep 2007
Chapter/Region: SCIC
Location: Socal
Vehicle:
2004 WRB STi
Full Race TS, BW 8374 EFR

Default

If an injector is stuck, what can be done about it? I'll also give your latency values a try.
methaddict is offline   Reply With Quote
Old 02-19-2008, 09:39 AM   #25
mickeyd2005
Scooby Newbie
 
Member#: 122595
Join Date: Aug 2006
Chapter/Region: NWIC
Vehicle:
2005 LGT Wagon
ABP

Default

If you have a stuck injector, you should be able to see it by logging roughness.

The modified injectors that I have seen need more latency. Even if the electric coil is the same, it takes slightly more time for flow to increase from 0 to 520 cc/min versus 0 to 816 cc/min.

Were your Perrin's straight from Perrin or were they previously used? Do you have the flow sheets?
mickeyd2005 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
Perrin modified sti sidefeed injectors 816cc methaddict Engine/Power/Exhaust 14 03-01-2008 08:28 PM
sti sidefeed latency settings for powerfc GShinji Pre-2002 Factory Turbo Powertrain 0 08-21-2007 06:32 PM
WTB: EcuTek reflashed STi ECU and Perrin Modified STi Injectors SupraScooby Private 'Wanted' Classifieds 0 11-06-2004 11:42 PM
Perrin modified STi injectors and Helix DP NIB turbohardtop Private 'For Sale' Classifieds 1 10-13-2004 09:57 AM
Perrin MODIFIED STI INJECTORS wrxstistunna Private 'For Sale' Classifieds 1 07-27-2004 06:46 AM


All times are GMT -4. The time now is 11:28 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.