Downshifting
07-12-2009, 01:16 PM
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Downshifting Just got my MCSS and love it. However, I noticed that it won't downshift to first until you get under 35 mph. Can this be tuned out to where if you're doing a higher speed it'll still downshift? In my Colorado, you could be doing a speed right up to redline in a lower gear and it would still downshift and run what little was left.
07-12-2009, 01:37 PM
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Good stuff. Now, on a MAF engine, does it matter much if you do Bolt-ons after the tune or before? Seems like you're just changing A/F rations withthe tune and the engine is making those happen no matter the conditions. Am I thinking correctly here?
07-12-2009, 02:53 PM
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No.
The MAF curve is set to define X amount of airflow per Y Hz of signal. While GM does a substantial amount of research into setting their MAF curve, there is variability in production. Up to a point, the fuel trims can compensate for the MAF being off, but STFT's disable when you go into open loop, and the LTFT's lock into their last value--who knows what AFR you actually get at WOT in this situation.
You really need a wideband and to tune your MAF and VE whenever you make mods that can affect airflow.
The MAF curve is set to define X amount of airflow per Y Hz of signal. While GM does a substantial amount of research into setting their MAF curve, there is variability in production. Up to a point, the fuel trims can compensate for the MAF being off, but STFT's disable when you go into open loop, and the LTFT's lock into their last value--who knows what AFR you actually get at WOT in this situation.
You really need a wideband and to tune your MAF and VE whenever you make mods that can affect airflow.
07-12-2009, 03:14 PM
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No.
The MAF curve is set to define X amount of airflow per Y Hz of signal. While GM does a substantial amount of research into setting their MAF curve, there is variability in production. Up to a point, the fuel trims can compensate for the MAF being off, but STFT's disable when you go into open loop, and the LTFT's lock into their last value--who knows what AFR you actually get at WOT in this situation.
You really need a wideband and to tune your MAF and VE whenever you make mods that can affect airflow.
The MAF curve is set to define X amount of airflow per Y Hz of signal. While GM does a substantial amount of research into setting their MAF curve, there is variability in production. Up to a point, the fuel trims can compensate for the MAF being off, but STFT's disable when you go into open loop, and the LTFT's lock into their last value--who knows what AFR you actually get at WOT in this situation.
You really need a wideband and to tune your MAF and VE whenever you make mods that can affect airflow.
