What are the air fuel ratio targets for tuned GTR? At which air fuel ratio is the car running to lean? If i dont see any knock on the car it means that the fuel ratio is ok ? Just want to make sure what to look out for when i do a data log?
Air Fuel Ratio Targets
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Yep, I tend to run 11.3-11.5 all the way to redline.
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How lean are you going on E85 Cicio?
12:8-13:0?
Working on that tune as we speak.
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That's like giving away the secret sauce in the KFC Chicken
Thats too lean though
~Cicio
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IMO when tuning with E85 I would use Lambda instead of AFR's the reading would be the same regardless of what fuel your using.
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The right air fuel ratio is the one that delivers peak torque with the correct Exhaust Gas Temperature.
Put an EGT gauge in an E85 burning VR38DETT and you will some interesting results!
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Put an EGT gauge in an E85 burning VR38DETT and you will some interesting results!
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I would think the stock manifolds probably heat up the EGT's a bit. Wonder how much that changes with new tubular manifolds.The right air fuel ratio is the one that delivers peak torque with the correct Exhaust Gas Temperature.
Put an EGT gauge in an E85 burning VR38DETT and you will some interesting results!![]()
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At that point might as well post the map lolThat's like giving away the secret sauce in the KFC Chicken![]()
Thats too lean though
~Cicio
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Most times I see 12.0-12.2 as measured on the car's O2 sensors on e85. A conservative tune will have them at 11.8.
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You definitely don't want to run too rich on E85.
For 93 octane 11.5:1 is what I target on both my EVO (34psi) and my GTR (19psi) using an actual wideband. However, in the software 'AFR (Old)' is offset from the actual AFR so I command 12.22 in the Fuel Low Det table, which gives me ~11.5:1 on the actual dyno wideband. In the EVO community most people target 12:1 using a gasoline lamda meter when tuning E85 so I would think you would want to see ~12.72:1 using 'AFR (Old)'. If you look at Jeff's map in the link below he commands ~12.22 in his Fuel Low Det table for E85.
http://www.gtrlife.c...l-lots-of-data/
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Fwiw Cobb has done away with AFR "old" in newer versions of the software and now "Air/Fuel Ratio" more closely mimics the tailpipe AFR. Accordingly it's not a good idea to target 12.2 in the tables on the newest revisions of AccessTuner.
EcuTek's AFR is similar to this.
EcuTek's AFR is similar to this.
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I read that as well so I decided to call Cobb to get the scoop. From what they told me, if you are an ATR user this will not affect your 'Fuel Low Det' tables so if you were commanding 12.22 before that number will stay the same. As you stated, the only change should be that 'AFR Old' is no longer used and "Air/Fuel Ratio" is now used and should better approximate the actual AFR value. I would personally want to verify this using an aftermarket wideband to understand the offset for my vehicle. I think Cobb is going to post something about his in the Cobb forum.
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