Ideal AFRs
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Join Date: Aug 2005
Location: Katy, Texas
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Ideal AFRs
OK guys I'm new to the EFI cars with my LS1 powered 2004 GTO, but have several carb hot rod cars and even use an AFR meter to tune on them. Fastest carb car is my 78 Trans Am 10.95s @ 123mph.
What are most of you all on your AFR running for a stock LS1? I had mine tuned yesterday and it started stock at 12.5 but it was richened to 11.5 to decrease the detonation. I had always read 12.5-13.3s for power. I understand fuel mixture as well as timing contribute to detonation but had always thought if it can't handle the timing you back it off, unless using N2O or boost then you stay "fat". The tuner said that is how they set up cars with exhaust manifolds, header cars they set up closer to 12.5.
Am I way off thinking keeping the AFR down in the high 12 range and dropping timing also to kill the detonation for the octane(93)?
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What are most of you all on your AFR running for a stock LS1? I had mine tuned yesterday and it started stock at 12.5 but it was richened to 11.5 to decrease the detonation. I had always read 12.5-13.3s for power. I understand fuel mixture as well as timing contribute to detonation but had always thought if it can't handle the timing you back it off, unless using N2O or boost then you stay "fat". The tuner said that is how they set up cars with exhaust manifolds, header cars they set up closer to 12.5.
Am I way off thinking keeping the AFR down in the high 12 range and dropping timing also to kill the detonation for the octane(93)?
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