MAF vs No MAF
Le Mans Master
Joined: Apr 2000
Posts: 6,341
Likes: 1
From: Shelton CT
Re: MAF vs No MAF (linkschamp)
I've done a LOT of reading lately on MAF vs SD conevrsions and for modified cars it ain't worth it I think.
The MAF (WHEN WORKING RIGHT) can adjust engine operation without any major reprogramming of the ECU/chips.
The SD system does away with the MAf so it opens up for a bit better breathing, but you have to program new chips for mods you do (Other than very basic bolt ons).
I'm staying with MAF, until I can afford a DFI system.. (In about 16years).. :jester
The MAF (WHEN WORKING RIGHT) can adjust engine operation without any major reprogramming of the ECU/chips.
The SD system does away with the MAf so it opens up for a bit better breathing, but you have to program new chips for mods you do (Other than very basic bolt ons).
I'm staying with MAF, until I can afford a DFI system.. (In about 16years).. :jester
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: MAF vs No MAF (linkschamp)
Speed density cars actually do a pretty good job of adjusting for mods. Maybe not quite so good as a MAF system, but good enough.
The early MAF's had a severe limitation in that it had a relatively low maximum value, once that was reached you couldn't tune very well because no matter how much air went through it, you only got the maximum value. I believe the newer ones have a much broader calibration range.
Who knows really, I've actually heard rumors that speed density is the better system until you get into the really high HP range. Either system has it's drawbacks. For example, I've never had a single problem with my MAF and I can say with 100% certainty that I never will.
The early MAF's had a severe limitation in that it had a relatively low maximum value, once that was reached you couldn't tune very well because no matter how much air went through it, you only got the maximum value. I believe the newer ones have a much broader calibration range.
Who knows really, I've actually heard rumors that speed density is the better system until you get into the really high HP range. Either system has it's drawbacks. For example, I've never had a single problem with my MAF and I can say with 100% certainty that I never will.
Melting Slicks
Joined: Aug 2000
Posts: 2,388
Likes: 42
From: Murrysville PA
Re: MAF vs No MAF (Nathan Plemons)
I switched to SD from the 89 MAF system. DFI btw is a simple version of GM's $8D speed density code used in 90-91 Corvettes. I like speed density better than the early MAF. MAF cars in principal are better for humidity changes and temp changes. The problem comes in when you start modifying the MAF and the intake tract and put bigger cams in. A MAF is dumb. It doe not know the amount of air the motor is sucking in. It knows how much should be going in. The flow is based on tables in the chip itself. So is Speed density. SD measures the engine vacuum. The less vacuum, the more the load. The amout of fuel the motor needs is plugged into a table that has manifold pressure on one side and RPM on the other. Its up to you to plug in the proper VE for that point. What you end up with is a VE curve that looks like your torque curve. I have much more control of my tuning with SD than MAF. If you have rich spots or lean spots with an MAF system, its harder to pin point the areas that need fooled with. The good part is that you generally do not have to fool with them unless your really **** about having 128/128 fuel trims at all times. So I like SD. Also my car starts alot quicker with SD. The newer MAF's used in the 94-96 LT's are much better than the old MAF cars.
