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Old 07-20-2023, 07:56 PM   #9
KingLT1


 
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Drives: 2016 1SS NFG A8
Join Date: Aug 2017
Location: 46804
Posts: 7,661
Quote:
Originally Posted by Chrome383Z View Post
Complete noob on tuning (mechanical ENG not electrical/controls lol) but do I need to rescale the MAF if I keep the STD rotofab? Let’s say I kept the STD rotofab and changed the snout and added a 103mm TB. Obviously the car is going to get more air, and would need more fuel, but I would think the MAF would still read as normal. I’m more familiar with Gen III cars and IIRC at WOT they went into PE which ignores the MAF and puts in a fixed amount of fuel. So I would think I would need to add more fuel in this scenario right? “Rescale MAF” I would think would need to be done if the diameter of the inlet tube changes (aka Big Gulp) or am I wrong?
No GM ECU that I recall ever ignored the maf signal for fueling in PE mode if dynamic airflow is disabled above set point. GM almost always disables dynamic airflow above 4k rpm and relies on MAF for final fueling. If the MAF is disabled then ECU relies on VE/VVE table for fueling. If the MAF curve is correct, then the AFR will hit the PE target.

That being said the 103 should not require rescaling the MAF, but you will likely need to adjust the virtual torque tables so the engine doesn't idle with negative timing.
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2016 NFG SS A8/Whipple 2.9/Fuel System/Flex Fuel
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