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Speed density vs. mass air

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Back in the day, everyone who had speed density was saving up for a mass air conversion. These days, almost everyone I see on HPT is deleting their MAF and raving about SD. I am experimenting with SD as a lock in my VE table, and have to say the truck absolutely runs better -- better throttle response, smoother idle, better SOTP...


What in the heck happened? Are the new computers somehow making MA worse than SD?


If I go down this road as a permanent change, what I am giving up (besides the 'self correction' of having a MAF -- which to me appears to be obfuscation of whats really happening on these new computers...) I know I'd need to relocate the IAT sensor, but I want to do that anyway.

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mass air systems can be problems on anything that's boosted or nitroused. this is even more concern on the newer, bigger, badder systems that are maxing out the mass air numbers allowed. it's more of an issue that speed density works very well on very high flow systems when they are tuned in. with mass air, you have to have the sensor so large that it isn't very good at reading low flow numbers. on the opposite end, trucks like your flow so much air it also max's out the readings it can make. lack of velocity. same rule applies to injectors. the factory won't go very big on them. instead they'll use two per cylinder if they have too.

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Erik, if you wanted to stay with a MAF, have you given the guys at Pro-M a call?



I have thought about Pro-M, but the truck is running very well in SD mode (of course it means more tuning though :banghead: I really hate my laptop now)


To be honest, I think the GM fueling algorithms for mass air suck (much like the spark logic...). The best thing I ever did in terms of stability of the tune and smoothness in the motor was unplug the MAF...

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Affect you mileage at all?


I can't say yet. I've been doing a lot of VE tuning (which means driving around in 1st or 2nd gear at high rpm), so the mileage ain't pretty (9.5).


What I can say is I've never felt this truck make so much power as this morning's run. It felt better than the Z06 pulling away from traffic at WOT. That's pretty subjective, I know, but today was really the first time I said "Damn" under my breath after nailing it from a stop light...


It impressed the Ford powerstroke so much he powerbraked until he smoked his rears at the next light.

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