Tuning For tuning and related discussions

A/F Ratio

Thread Tools
 
Search this Thread
 
Old Apr 22, 2009 | 09:44 AM
  #1  
Dunkinuts's Avatar
Thread Starter
Senior Member
 
Joined: 10-28-07
Posts: 3,713
Likes: 0
From: Tall Timbers, MD
A/F Ratio

Okay so I got a DashHawk this week and I have played around with the settings and done some data logging. I know I don't have a wideband but I have been logging the command a/f ratio and it does stay at 14.7:1 for most of the time. but under WOT I have seen it drop to the low 11.x:1.

The reason I am asking is it doesn't normally do this until 5500 rpm or so. is it a mile per hour thing or an engine load setting? I am not tuning anything, yet, and only have an intake in terms of power mods.
Reply
Old Apr 22, 2009 | 10:32 AM
  #2  
Jrhdpaintball's Avatar
Senior Member
 
Joined: 11-12-07
Posts: 1,537
Likes: 0
From: Maryland
when you go to WOT your car goes into power enrichment mode, which commands and differant afr... and just because its commanding 11.5 for example does not mean your accual afr is 11.5...

i think im correct on this...im still learning tuning so i might be wrong
Reply
Old Apr 22, 2009 | 10:42 AM
  #3  
Dunkinuts's Avatar
Thread Starter
Senior Member
 
Joined: 10-28-07
Posts: 3,713
Likes: 0
From: Tall Timbers, MD
Originally Posted by Jrhdpaintball
when you go to WOT your car goes into power enrichment mode, which commands and differant afr... and just because its commanding 11.5 for example does not mean your accual afr is 11.5...

i think im correct on this...im still learning tuning so i might be wrong
right i know it isn't my a/f ratio but it is what the PCM is telling the car to aim for. But BennyHHR told me it is the PE delay and that is can me removed. But I need tuning software first. But is the low 11s to low for WOT at high RPMS?
Reply
Old Apr 22, 2009 | 10:45 AM
  #4  
light'bolt's Avatar
Senior Member
 
Joined: 11-23-06
Posts: 2,855
Likes: 0
From: Texas boy stuck in an Iowa Cornfield
not really, some wil argue yes and like to be in the 12's. I'm a little conservitive and have my PE set to 11.5.




edit: I just looked at what type of car you have and yes 11's are a little rich for N/A cars, I have my truck PE set to 12.8
Reply
Old Apr 22, 2009 | 10:49 AM
  #5  
lsjwannabe's Avatar
Senior Member
iTrader: (1)
 
Joined: 01-23-06
Posts: 10,731
Likes: 0
From: on here
Your forgetting he is n/a not s/c. Its a rich, but thats a gm tune for you. Most n/a cars shoot for a 12.8~13.0 afr when fine tuning.
Reply
Old Apr 22, 2009 | 10:50 AM
  #6  
Dunkinuts's Avatar
Thread Starter
Senior Member
 
Joined: 10-28-07
Posts: 3,713
Likes: 0
From: Tall Timbers, MD
Originally Posted by light'bolt
not really, some wil argue yes and like to be in the 12's. I'm a little conservitive and have my PE set to 11.5.
and what all does having the PE set to a lower ratio do/mean. keep in mind I am pretty much a n00b when it comes to tunes.
Reply
Old Apr 22, 2009 | 10:55 AM
  #7  
light'bolt's Avatar
Senior Member
 
Joined: 11-23-06
Posts: 2,855
Likes: 0
From: Texas boy stuck in an Iowa Cornfield
sorry Power Enrichment, PE, is a table on HPTuners to adjust the AFR during WOT, or past a certain % Throttle Position
Reply
Old Apr 22, 2009 | 10:56 AM
  #8  
Dunkinuts's Avatar
Thread Starter
Senior Member
 
Joined: 10-28-07
Posts: 3,713
Likes: 0
From: Tall Timbers, MD
Originally Posted by light'bolt
sorry Power Enrichment, PE, is a table on HPTuners to adjust the AFR during WOT, or past a certain % Throttle Position
got ya is that only for HPtuners?
Reply
Old Apr 22, 2009 | 11:29 AM
  #9  
Jrhdpaintball's Avatar
Senior Member
 
Joined: 11-12-07
Posts: 1,537
Likes: 0
From: Maryland
not sure... ive got hptuners... sounds like your local... havnt messed with any NA cars but im sure someone could hook you up with a toon... or i can lean it out for you. thats not a problem... just need a afr gauge
Reply
Old Apr 22, 2009 | 11:34 AM
  #10  
Dunkinuts's Avatar
Thread Starter
Senior Member
 
Joined: 10-28-07
Posts: 3,713
Likes: 0
From: Tall Timbers, MD
^^^ since I am an 08 HPtuners doesn't work for my ECU yet. LSedit and Trifecta and JET are the only PCM/ECU tunes i can get at the moment.
Reply
Old Apr 22, 2009 | 11:43 AM
  #11  
elecblue06's Avatar
Senior Member
iTrader: (1)
 
Joined: 03-19-07
Posts: 14,901
Likes: 1
From: newburgh,ny
NA should be tuned for 13 or so like people ahve said .. cruise/ idle should be 14.7 ..

also like said jsut because you're commanding 11 AFR at WOT doesn't mean thats what you're getting .. however. it shouldnt be commandin that low either lol
Reply
Old Apr 22, 2009 | 12:02 PM
  #12  
Dunkinuts's Avatar
Thread Starter
Senior Member
 
Joined: 10-28-07
Posts: 3,713
Likes: 0
From: Tall Timbers, MD
damn GM tune!!!!!
Reply
Old Apr 22, 2009 | 02:25 PM
  #13  
BennyHHR's Avatar
Junior Member
 
Joined: 10-26-06
Posts: 454
Likes: 0
From: SE VA
The low 11's you're seeing is likely COT (Cat Over Temp) algorythms kicking in on a hard pull.

A normal GM tune will hold stoic (14.7) for a bit due to PE delay. Then it will go richer in a more normal range (about 12 - 13), then when COT enables, you'll see it go pig rich.

The PE delay helps GM perform well for standard smog and MPG tests, but will loose power during that. COT protects the catalyst (and GM).

IOW, good for GM, but not for best power. Hey, that's why we tune!!

Dunkin, you mentioned your's is an '08 (E37 ECM), not supported by HPTuners yet, and available choices. It all depends on what your goals are. Learning good tuning takes a LOT of time and effort. Stay away from the Jet crap. Either invest in EFILive, LS2Edit and be ready for a learning adventure, otherwise your best bet would be to just go with Trifecta. He's good.
Reply
Old Apr 22, 2009 | 02:33 PM
  #14  
Dunkinuts's Avatar
Thread Starter
Senior Member
 
Joined: 10-28-07
Posts: 3,713
Likes: 0
From: Tall Timbers, MD
Originally Posted by BennyHHR
The low 11's you're seeing is likely COT (Cat Over Temp) algorythms kicking in on a hard pull.

A normal GM tune will hold stoic (14.7) for a bit due to PE delay. Then it will go richer in a more normal range (about 12 - 13), then when COT enables, you'll see it go pig rich.

The PE delay helps GM perform well for standard smog and MPG tests, but will loose power during that. COT protects the catalyst (and GM).

IOW, good for GM, but not for best power. Hey, that's why we tune!!

Dunkin, you mentioned your's is an '08 (E37 ECM), not supported by HPTuners yet, and available choices. It all depends on what your goals are. Learning good tuning takes a LOT of time and effort. Stay away from the Jet crap. Either invest in EFILive, LS2Edit and be ready for a learning adventure, otherwise your best bet would be to just go with Trifecta. He's good.
yeah I am leaning towards LS2edit, and I am very willing to crunch numbers and do some trial and error.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
DocSvensk
2.0L LNF Performance Tech
7
Sep 27, 2015 02:24 PM
polo708
2.0L LSJ Performance Tech
40
Jul 10, 2006 03:56 PM
Twincharged
2.0L LSJ Performance Tech
9
Feb 1, 2006 09:12 AM
silverSS
2.0L LSJ Performance Tech
21
Jan 17, 2006 07:46 AM
Jmc007
2.0L LSJ Performance Tech
91
Dec 4, 2005 05:22 PM




All times are GMT -4. The time now is 07:39 PM.