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Old 10-13-2008, 01:40 PM   #1
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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).
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Old 10-13-2008, 01:45 PM   #2
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Your AFR values sound reasonable to me. I generally don't recommend 14.7:1 at 100 kPa, boosted or not.
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Old 10-18-2008, 11:16 AM   #3
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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
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Old 10-18-2008, 11:38 AM   #4
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Quote:
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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.
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Old 10-18-2008, 01:00 PM   #5
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16-17:1 might be ok if you're running the proper advance in those bins, otherwise your EGTs might be a bit high
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Old 10-18-2008, 01:17 PM   #6
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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.
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Old 10-18-2008, 02:25 PM   #7
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I'm currently stock except for MS, and deleted AFM. I was trying to keep things economical until I get to go turbo.
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Old 10-18-2008, 02:32 PM   #8
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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.
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Old 10-18-2008, 03:57 PM   #9
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Without someone to drive the car for me is there a way I can adjust fuel to fix this, other than a dyno.
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Old 10-18-2008, 03:57 PM   #10
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Megalogviewer
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Old 10-18-2008, 04:08 PM   #11
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Quote:
Originally Posted by johndoe View Post
Megalogviewer
+1

MLV is your friend.
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Old 10-18-2008, 04:35 PM   #12
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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.
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Old 10-18-2008, 05:31 PM   #13
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yeah, it takes time. You need to log for at least 20 minutes for it to be worthwile.
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Old 10-18-2008, 05:54 PM   #14
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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.
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Old 10-19-2008, 01:10 PM   #15
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Old 10-19-2008, 01:24 PM   #16
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Thats not how my table looks

Last edited by apariah; 10-19-2008 at 01:37 PM.
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Old 10-19-2008, 01:26 PM   #17
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Quote:
Originally Posted by apariah View Post
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.
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Old 10-19-2008, 01:45 PM   #18
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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 02:06 PM.
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Old 10-19-2008, 02:26 PM   #19
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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.
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Old 10-19-2008, 02:47 PM   #20
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maybe you should post a screen shot of your AFR table before you get ahead of yourself.
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