MEGAsquirt A place to collectively sort out this megasquirt gizmo

NA car, WOT, how lean is OK

Thread Tools
 
Search this Thread
 
Old 10-13-2008, 12:40 PM
  #1  
Newb
Thread Starter
 
woodc's Avatar
 
Join Date: Jul 2008
Location: Western NC
Posts: 31
Total Cats: 0
Default NA car, WOT, how lean is OK

My target AFRs are 12.8-13.1 at 89-101 kPa on my track only NA car.

I see other folks with as high as 14.7 (although they are boosted) at the same map levels?

I am looking for max power thus the 12.8 to 13.1 numbers but am just curious as to how lean is OK before I need to start worrying should it magically start running leaner on track... (and it seems to vary based on what gear I am in and high RPM/high gears have not seen much action on the street).
woodc is offline  
Old 10-13-2008, 12:45 PM
  #2  
Supporting Vendor
 
Matt Cramer's Avatar
 
Join Date: Sep 2006
Posts: 2,332
Total Cats: 67
Default

Your AFR values sound reasonable to me. I generally don't recommend 14.7:1 at 100 kPa, boosted or not.
__________________
Matt Cramer
www.diyautotune.com
Matt Cramer is offline  
Old 10-18-2008, 10:16 AM
  #3  
Senior Member
 
apariah's Avatar
 
Join Date: Apr 2008
Location: NHR, TX
Posts: 538
Total Cats: -2
Default

Would that mean hitting 17plus while off, or slighty pressing the throttle is really bad. Under load, I'm below 13.4, but often when off throttle (Understandably) or just barely pressing the gas I'm getting 16-17 plus
apariah is offline  
Old 10-18-2008, 10:38 AM
  #4  
Elite Member
iTrader: (3)
 
Arkmage's Avatar
 
Join Date: May 2006
Location: Houston, TX
Posts: 2,895
Total Cats: 0
Default

Originally Posted by apariah
Would that mean hitting 17plus while off, or slighty pressing the throttle is really bad. Under load, I'm below 13.4, but often when off throttle (Understandably) or just barely pressing the gas I'm getting 16-17 plus
that's fine for cruising speeds, it's only heavy throttle and wide open throttle that you need to stay a bit rich at.
Arkmage is offline  
Old 10-18-2008, 12:00 PM
  #5  
Elite Member
iTrader: (5)
 
johndoe's Avatar
 
Join Date: Mar 2007
Location: NYC
Posts: 1,970
Total Cats: 1
Default

16-17:1 might be ok if you're running the proper advance in those bins, otherwise your EGTs might be a bit high
johndoe is offline  
Old 10-18-2008, 12:17 PM
  #6  
Elite Member
iTrader: (16)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 9,295
Total Cats: 476
Default

My 99' likes her fuel. I run it 12.5 at lower RPMs at 101kPa and it tapers to 12.0:1 at higher RPMs.
patsmx5 is offline  
Old 10-18-2008, 01:25 PM
  #7  
Senior Member
 
apariah's Avatar
 
Join Date: Apr 2008
Location: NHR, TX
Posts: 538
Total Cats: -2
Default

I'm currently stock except for MS, and deleted AFM. I was trying to keep things economical until I get to go turbo.
apariah is offline  
Old 10-18-2008, 01:32 PM
  #8  
Elite Member
iTrader: (16)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 9,295
Total Cats: 476
Default

Running 16:1 without an egt gauge to verify safe temps could cause burned valves. 17:1 can cause burned valves with a perfect timing table depending on the engine. 17+ you're gonna break your ****. And rebuilding a head is not exactly economical.
patsmx5 is offline  
Old 10-18-2008, 02:57 PM
  #9  
Senior Member
 
apariah's Avatar
 
Join Date: Apr 2008
Location: NHR, TX
Posts: 538
Total Cats: -2
Default

Without someone to drive the car for me is there a way I can adjust fuel to fix this, other than a dyno.
apariah is offline  
Old 10-18-2008, 02:57 PM
  #10  
Elite Member
iTrader: (5)
 
johndoe's Avatar
 
Join Date: Mar 2007
Location: NYC
Posts: 1,970
Total Cats: 1
Default

Megalogviewer
johndoe is offline  
Old 10-18-2008, 03:08 PM
  #11  
Elite Member
iTrader: (24)
 
kotomile's Avatar
 
Join Date: Oct 2006
Location: Monterey, CA
Posts: 7,537
Total Cats: 42
Default

Originally Posted by johndoe
Megalogviewer
+1

MLV is your friend.
kotomile is offline  
Old 10-18-2008, 03:35 PM
  #12  
Senior Member
 
apariah's Avatar
 
Join Date: Apr 2008
Location: NHR, TX
Posts: 538
Total Cats: -2
Default

The analyze feature, thats What I did previously, will using it multiple times refine the settings? I'm still very unclear on manually adjusting the Fuel tables.
apariah is offline  
Old 10-18-2008, 04:31 PM
  #13  
Elite Member
iTrader: (5)
 
johndoe's Avatar
 
Join Date: Mar 2007
Location: NYC
Posts: 1,970
Total Cats: 1
Default

yeah, it takes time. You need to log for at least 20 minutes for it to be worthwile.
johndoe is offline  
Old 10-18-2008, 04:54 PM
  #14  
Senior Member
 
apariah's Avatar
 
Join Date: Apr 2008
Location: NHR, TX
Posts: 538
Total Cats: -2
Default

Thanks I did that last night, but thought I did it too long for it to be worth while. Does it matter how I drive, lat time I got a alert about using VE for higher RPM tuning.
apariah is offline  
Old 10-19-2008, 12:10 PM
  #15  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

hustler is offline  
Old 10-19-2008, 12:24 PM
  #16  
Senior Member
 
apariah's Avatar
 
Join Date: Apr 2008
Location: NHR, TX
Posts: 538
Total Cats: -2
Default

Thats not how my table looks

Last edited by apariah; 10-19-2008 at 12:37 PM.
apariah is offline  
Old 10-19-2008, 12:26 PM
  #17  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

Originally Posted by apariah
Thanks I did that last night, but thought I did it too long for it to be worth while. Does it matter how I drive, lat time I got a alert about using VE for higher RPM tuning.
lol, I know of 3 MS cars which used 121 for road tuning now, lol.
hustler is offline  
Old 10-19-2008, 12:45 PM
  #18  
Senior Member
 
apariah's Avatar
 
Join Date: Apr 2008
Location: NHR, TX
Posts: 538
Total Cats: -2
Default

Their are 3 of us around here now? BTW, my VE Table shows whole numbers nothing with a decimal, or anything that I recognize as a A/F Ratio Hustler where did you go to get that table?

Last edited by apariah; 10-19-2008 at 01:06 PM.
apariah is offline  
Old 10-19-2008, 01:26 PM
  #19  
Senior Member
 
apariah's Avatar
 
Join Date: Apr 2008
Location: NHR, TX
Posts: 538
Total Cats: -2
Default

Last night may have been more eye opening than I thought it was, I found out I have to remove my A/F gauge, and I based on what I just read in regards to burnt valves I think I may have to rebuild my head. We noticed last night my car sometimes smells of raw fuel, I thought this was because I was running rich, but I never even considered a burned valve could allow raw fuel into the exhaust. This could suck.
apariah is offline  
Old 10-19-2008, 01:47 PM
  #20  
Elite Member
iTrader: (5)
 
johndoe's Avatar
 
Join Date: Mar 2007
Location: NYC
Posts: 1,970
Total Cats: 1
Default

maybe you should post a screen shot of your AFR table before you get ahead of yourself.
johndoe is offline  


Quick Reply: NA car, WOT, how lean is OK



All times are GMT -4. The time now is 01:09 AM.