Welcome to the North American Subaru Impreza Owners Club Saturday July 12, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
South West Impreza Club
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 Chapters > South West Impreza Club Forum -- SWIC

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 07-14-2013, 02:15 AM   #1
coyotesfan
Scooby Newbie
 
Member#: 321690
Join Date: May 2012
Location: Chandler
Vehicle:
2009 STi hatchback
white

Default Looking for some help with basic break-in tune using AP on 09 STi

Was wondering if someone local in the AZ east valley (chandler/gilbert area) might have some time Sunday 7/14 to help a fellow subie. I just got done installing a new built short block with some mods:

* TGVs deleted
* SAI deleted
* 7mm phenolic intake spacers
* aftermarket turbo uppipe
* aftermarket turbo inlet pipe
* 750cc injectors
* walbro 255 pump

I am trying to get a break-in tune set-up using Accesstuner Race. I am basing the tune off of Cobb Stg 2 ACN91 lwg which I was running prior to the new engine. The engine starts but runs rough, I am trying to scale for the injectors and get it running good enough so I can break it in, and then head over to FAT for a proper tune. I already asked FAT for a break-in tune but I've been out of town last week and not able to call them for follow-up. I was hoping to drive it tomorrow, I need to go to the airport Monday morning.

If anyone might be available for like 30 mins before noon or after 5pm I would appreciate it! I understand the basics of accesstuner race but it would give me a boost of confidence with someone experienced looking over my shoulder. Just looking to dial in A/F corr, not worried about tuning timing/boost. I already disabled the DTCs for the TGV and SAI deletes.
* Registered users of the site do not see these ads.
coyotesfan is offline   Reply With Quote
Old 07-14-2013, 11:38 AM   #2
brocksdad
Scooby Specialist
 
Member#: 107352
Join Date: Feb 2006
Chapter/Region: SWIC
Vehicle:
Not Respectable

Default

What kind of car is it? What kind of 750 injectors? There is information to be found about the latency values for most of the popular injectors around the web, if those values weren't provided.

Cobb's injector scale is pretty weird. I don't know if you've already done it or know how, but this is right from Cobb's tuning guide:

Quote:
To calculate a starting value for a different injector size than stock, use the following formula:
New Scale Value = (Original Injector Size / New Injector Size) * Original Scale Value.
For example, letís say you are replacing your factory WRX injectors (420cc) for aftermarket 650cc injectors. The formula would look like:
New Scale Value = (420cc / 650cc) * 6442;
New Scale Value = 4162
For another example, letís say you are replacing your factory 2004+ USDM STi injectors (500cc) for aftermarket
850cc injectors. The formula would look like:
New Scale Value = (500cc / 850cc) * 5372;
New Scale Value = 3160
Maybe I missed it, but I didn't see any intake listed in your mods. If it's a stock MAF housing there will only need to be minimal adjustments if any at all. The MAF scaling is pretty simple in the Access Tuner software because of live tuning. You can actually see your changes as they're made. Basically you want your fuel trims to be as close to "0" as possible. Any value in the single digits (+/-9) will be ok to limp the car around until you get it properly tuned. Keep in mind that the injector scale and latency values will effect your fuel trims as well so you need to get those dialed in first.
brocksdad is offline   Reply With Quote
Old 07-14-2013, 01:58 PM   #3
coyotesfan
Scooby Newbie
 
Member#: 321690
Join Date: May 2012
Location: Chandler
Vehicle:
2009 STi hatchback
white

Default

Quote:
Originally Posted by brocksdad View Post
What kind of car is it? What kind of 750 injectors? There is information to be found about the latency values for most of the popular injectors around the web, if those values weren't provided.

Cobb's injector scale is pretty weird. I don't know if you've already done it or know how, but this is right from Cobb's tuning guide:



Maybe I missed it, but I didn't see any intake listed in your mods. If it's a stock MAF housing there will only need to be minimal adjustments if any at all. The MAF scaling is pretty simple in the Access Tuner software because of live tuning. You can actually see your changes as they're made. Basically you want your fuel trims to be as close to "0" as possible. Any value in the single digits (+/-9) will be ok to limp the car around until you get it properly tuned. Keep in mind that the injector scale and latency values will effect your fuel trims as well so you need to get those dialed in first.
Hey thanks for the response. It's a 2009 STi. The injectors are Fuel Injector Connection 750cc injectors, and I had them flowed at Fuel Inj Clinic, they all ran 760 +/- a couple %. I did search the web, even emailed the company for at least latency value at 14v, didn't get a response.

I understand Cobb's scaling equation. I made some progress this morning, got my A/F corr close to 0 when idling, and A/F learning was like +4%. I then went to drive it around the block and it's running rough. I data logged and the A/F corr was jumping around between +/- 20%, and the A/F learning was 0~3%. The check engine light and cruise light flashed briefly a couple of times - like I was misfiring. But no DTCs for misfiring were registered. It feels like the engine is misfiring - runs rough, low power.

The only thing I am struggling with is that the idle vacuum is 8.5~8.7 psi, it was 10 psi on my old engine. Would a vac leak throw off the injector control?

The weird thing is that I had to raise the injector scalar to 4722 to get the fuel trims down. This seems way too high of a scalar for 750cc injectors. The base scalar from the Cobb map (Stg 2 ACN91 lwg) was 4813.
coyotesfan is offline   Reply With Quote
Old 07-14-2013, 07:01 PM   #4
brocksdad
Scooby Specialist
 
Member#: 107352
Join Date: Feb 2006
Chapter/Region: SWIC
Vehicle:
Not Respectable

Default

A vacuum leak would make a problem for your fuel trims. You are allowing unmetered air into the system and the A/F corrections would be trying to add fuel into the mix to compensate for the extra air.

Again, what intake do you have? Anything other than a stock sized MAF housing will play a huge part of the equation. Do you have an aftermarket BOV on the car?
brocksdad is offline   Reply With Quote
Old 07-14-2013, 07:25 PM   #5
coyotesfan
Scooby Newbie
 
Member#: 321690
Join Date: May 2012
Location: Chandler
Vehicle:
2009 STi hatchback
white

Default

Quote:
Originally Posted by brocksdad View Post
A vacuum leak would make a problem for your fuel trims. You are allowing unmetered air into the system and the A/F corrections would be trying to add fuel into the mix to compensate for the extra air.

Again, what intake do you have? Anything other than a stock sized MAF housing will play a huge part of the equation. Do you have an aftermarket BOV on the car?
I have just stock intake. No aftermarket BOV. I am leaning towards a vac/boost leak given my reduced idle vac levels. Gonna go hunting with some carb cleaner spray.
coyotesfan is offline   Reply With Quote
Old 07-15-2013, 12:32 AM   #6
Z0rr0
Scooby Specialist
 
Member#: 23123
Join Date: Aug 2002
Chapter/Region: SWIC
Location: Gilbert, AZ
Vehicle:
07 335i SRP Tuned
13 Scion FR-S

Default

I do not believe FAT currently has a tuner. Snail performance is not there any more.

I'd be happy to help ya out. Txt or call 4807459967
Z0rr0 is offline   Reply With Quote
Old 07-15-2013, 08:01 PM   #7
Poweredbysnail
Scooby Specialist
 
Member#: 74753
Join Date: Nov 2004
Chapter/Region: BAIC
Location: Snail Performance
Vehicle:
2003 Wrx 2.5Lw/gt30r
Team Snail

Default

Quote:
Originally Posted by Z0rr0 View Post
I do not believe FAT currently has a tuner. Snail performance is not there any more.

I'd be happy to help ya out. Txt or call 4807459967

Hit up Travis "Z0rr0" he can get you hooked up. I build a map for your car and sent it to FAT but I'm sure it was lost due to Taylor not being there anymore now.

Travis
Snail Performance
Poweredbysnail is offline   Reply With Quote
Old 07-15-2013, 11:24 PM   #8
coyotesfan
Scooby Newbie
 
Member#: 321690
Join Date: May 2012
Location: Chandler
Vehicle:
2009 STi hatchback
white

Default

Thanks guys. I had it towed today to FAT so they could troubleshoot it. I definitely be following up on a tune. I am in Nashville through Thurs. I appreciate the responses.
coyotesfan is offline   Reply With Quote
Old 07-16-2013, 01:17 AM   #9
Z0rr0
Scooby Specialist
 
Member#: 23123
Join Date: Aug 2002
Chapter/Region: SWIC
Location: Gilbert, AZ
Vehicle:
07 335i SRP Tuned
13 Scion FR-S

Default

Thanks Travis, coyotesfan, let me know when you want me to take a look at it.
Z0rr0 is offline   Reply With Quote
Old 07-16-2013, 11:46 AM   #10
theatkinsdiet317
Scooby Newbie
 
Member#: 334724
Join Date: Oct 2012
Chapter/Region: SWIC
Location: Tempe, AZ
Vehicle:
2002 WRX wagon
PSM

Default

^^bump for Travis (Z0rr0) tuning. He does a great job and will explain everything, your car will thank you lol
theatkinsdiet317 is offline   Reply With Quote
Old 07-16-2013, 02:45 PM   #11
WRX357
Scooby Specialist
 
Member#: 224249
Join Date: Sep 2009
Chapter/Region: SWIC
Location: Phx, AZ
Vehicle:
2002 Subiworx built/
Soulless tuned Bugeye

Default

Quote:
Originally Posted by theatkinsdiet317 View Post
^^bump for Travis (Z0rr0) tuning. He does a great job and will explain everything, your car will thank you lol
infinity times infinity for Travis/Z0rr0
He may have no soul but he has the knowledge to tune.
WRX357 is offline   Reply With Quote
Old 07-16-2013, 02:56 PM   #12
Z0rr0
Scooby Specialist
 
Member#: 23123
Join Date: Aug 2002
Chapter/Region: SWIC
Location: Gilbert, AZ
Vehicle:
07 335i SRP Tuned
13 Scion FR-S

Default

We were looking for infinity plus infinity.. lol
Z0rr0 is offline   Reply With Quote
Old 07-18-2013, 10:47 AM   #13
coyotesfan
Scooby Newbie
 
Member#: 321690
Join Date: May 2012
Location: Chandler
Vehicle:
2009 STi hatchback
white

Default

Update: FAT found my #4 injector pig tail was tweaked and somehow #4 wasn't delivering fuel. Then the owner (Robert I think) explained to me a whole bunch of issues he thought was wrong with car, but he didn't know I hadn't tuned it yet, it had a DTC for one tgv being closed. I explained that this was a new engine and I had deleted the tgv's along with other mods. I had mentioned this to the guy that answered the phone when I arranged to have it towed over there. Apparently that wasn't relayed to Robert. And to make it worse I was not able to be there in person to talk with them when my car was dropped off. My bad on that.

So I guess there was miscommunication on both sides, but I sensed Robert was frustrated, it may be due to their recent turnover. He was very direct with me (kind of scolded me for not having a pro tune on it) and i was a bit surprised with that.

I hope that FAT can remain a good shop, they're somewhat close for me. I guess I'll be considering working with subiworx in the future. But I would still say they are a decent shop and I'm not bashing them.
coyotesfan is offline   Reply With Quote
Old 07-19-2013, 02:21 AM   #14
brocksdad
Scooby Specialist
 
Member#: 107352
Join Date: Feb 2006
Chapter/Region: SWIC
Vehicle:
Not Respectable

Default

Glad you figured out what the problem was. In the future, if you have an issue similar to this, you can look at the "Roughness Monitors" to see if a cylinder is misfiring.

Quote:
Originally Posted by coyotesfan View Post
So I guess there was miscommunication on both sides, but I sensed Robert was frustrated, it may be due to their recent turnover. He was very direct with me (kind of scolded me for not having a pro tune on it) and i was a bit surprised with that.
I don't think the frustration was a result of the recent happenings at the shop. That's just the way he is. You probably caught him on a good day. lol
brocksdad is offline   Reply With Quote
Old 07-20-2013, 01:02 AM   #15
coyotesfan
Scooby Newbie
 
Member#: 321690
Join Date: May 2012
Location: Chandler
Vehicle:
2009 STi hatchback
white

Default

Thanks everyone. Travis hooked me up with a conservative tune for my break in. Car is running is good A/F's and I'm finally back in the boost (albeit 7psi).

Final tune coming after break in. I see corn in my future.
coyotesfan 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


All times are GMT -4. The time now is 05:06 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.