What are the advantages in tuning via speed density?
Mainly just curious, I keep seeing people going to SD tunes, and was curious why they were doing so, what the advantages are? Is it simply because HP Tuners has made it possible, and people are just experimenting or are there performance/tuning advantages to it?
Thanks, Shawn
Talk to someone who's car is SD from the factory and they are looking for an MAF kit.
Talk to someone who's car is MAF from the factory and they are looking for a SD tune.
You can make slightly more power with an SD tune if you change the induction system (ie get rid of the MAF). Additionally, with larger cams SD tuning will give better driveability. Aside from that though, it is just gives tuners something to 'tune'. Kinda like Lterms......
Talk to someone who's car is SD from the factory and they are looking for an MAF kit.
Talk to someone who's car is MAF from the factory and they are looking for a SD tune.
You can make slightly more power with an SD tune if you change the induction system (ie get rid of the MAF). Additionally, with larger cams SD tuning will give better driveability. Aside from that though, it is just gives tuners something to 'tune'. Kinda like Lterms......

Wow havent seen you around in a while. Did you come to the EFA shootout this weekend?
I literally had to blow the dust off of my tuning laptop, so I have some catching up to do. I'll be on the boards more often now to help with the 'old school tuning methods'
questions, and learn a bit about how much SD tuning has taken off. It is amazing how far it has come. I remember when it was just several shops around the US and the Auzzies performing the 'top secret' SD tuning. The LS1 tuning community has really advanced in the past year or so. have proper low RPM and transient-throttle fueling.
MAF or no MAF. Some people want to go SD-only,
they have their reasons. The MAF is not a bad
instrument and if you calibrate it right it has better
fidelity against environmentals and mods, with no
further fiddling, than the speed density alone. The
restriction aspect falls away when you go to a
descreened 85mm (but, see calibration). Not that
most of us are MAF-limited anyway.
SD+MAF = belt+suspenders; some folks are just
looking for the proper leopard loincloth, is all.
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Last edited by Gary Z; Jun 8, 2005 at 02:28 AM.
Mainly just curious, I keep seeing people going to SD tunes, and was curious why they were doing so, what the advantages are? Is it simply because HP Tuners has made it possible, and people are just experimenting or are there performance/tuning advantages to it?
Thanks, Shawn
Thanks for asking the question. I was just about to do it myself. HORIST in all his wisdom has tried a hell of a lot to enlighten me but being the dumbass that I am I just cant grasp it at times. Or more like I just get frustrated because Im still tuning it lol. This is what I get from the answers that I saw. Basically in newb terms.... tuning it in SD and then calibrating the MAF is like a "you scratch my back I scratch yours" kinda thing. They both support each other. The SD is a primary tune and the MAF will help out in times of .. lets say shitty weather. YES... NO... HELL I dont know. Tell me if thats it in a nutshell.
the MAF just measures air going thru it.. but if you know the air going into the motor, you can calculate fuel from that.
the computer (when in stock mode) uses a combination of both... if you tune and tweek both to be accurate, you'll get best driveability and fuel economy... if you leave it in SD.... eh, you still probly wont notice much of a diff.
2 bar is for forced induction cars (turbo, supercharger, ect)
atmospheric pressure at sea level is 14.7PSI or 1 bar.
stock, you have a 1 bar MAP (manifold absolute pressure) sensor it measures from absolute vacuum to 14.7 PSI absolute ( aka normal air pressure at sea level)
a 2 bar map can go 14.7 PSI above that... aka 14.7 PSI of boost at sea level...
make sense?
If your maf is not maxing out, I don't see the benefit of going to 2 bar, but my opinion of the maf is good

Ryan






