ltft's
May 20, 2011, 04:50 PM
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ltft's
hey guys, i've been looking at my logs and noticed all my ltft's are always negative. usually ranging from -3 to -7 and at some times it reaches -9. highest it's gotten is 0. is this horrible for my car?
May 21, 2011, 02:46 AM
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alrighty good i was getting concerned, i've looked at other peoples logs and they get positive numbers and nothing as far negative as i do and my exhaust is no longer covered in soot after 2 days. just trying to make sure im not running lean while i wait for my wideband to show up
May 21, 2011, 11:31 AM
#5
Well when at 5psi or greater boost the AFR's depend more on how it was tuned.
For closed loop where the O2 sensor is trying to keep the AFR's around 14.7 the LTFT's will adjust up and down based on what it learns. If it's hovering between -3 and -7 that actually means it's trying to REMOVE 3%-7% fuel on average to reach the 14.7 AFR's during cruise. It's still within the ECU's adjustment range so not horrible but it might remove a bit more fuel than expected as the turbo is spooling depending on where your Hz crossover is set.
Has anyone tuned you car?
For closed loop where the O2 sensor is trying to keep the AFR's around 14.7 the LTFT's will adjust up and down based on what it learns. If it's hovering between -3 and -7 that actually means it's trying to REMOVE 3%-7% fuel on average to reach the 14.7 AFR's during cruise. It's still within the ECU's adjustment range so not horrible but it might remove a bit more fuel than expected as the turbo is spooling depending on where your Hz crossover is set.
Has anyone tuned you car?
May 25, 2011, 01:35 PM
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Well when at 5psi or greater boost the AFR's depend more on how it was tuned.
For closed loop where the O2 sensor is trying to keep the AFR's around 14.7 the LTFT's will adjust up and down based on what it learns. If it's hovering between -3 and -7 that actually means it's trying to REMOVE 3%-7% fuel on average to reach the 14.7 AFR's during cruise. It's still within the ECU's adjustment range so not horrible but it might remove a bit more fuel than expected as the turbo is spooling depending on where your Hz crossover is set.
Has anyone tuned you car?
For closed loop where the O2 sensor is trying to keep the AFR's around 14.7 the LTFT's will adjust up and down based on what it learns. If it's hovering between -3 and -7 that actually means it's trying to REMOVE 3%-7% fuel on average to reach the 14.7 AFR's during cruise. It's still within the ECU's adjustment range so not horrible but it might remove a bit more fuel than expected as the turbo is spooling depending on where your Hz crossover is set.
Has anyone tuned you car?
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