why go mass air???

[wildstang87]

i dont fully understand why maf is better than speed density?? can someone explain it to me. i know how both work, but i dont see why with a good set of heads, cam, intake, injectors, adjustable pressure regulator and exhaust, you cant make as much horspower with speed density as you can with maf. or am i wrong and its just a driveability thing???
the reason i ask is b/c id rather spend the $500 on something besides just a maf conversion. ANY HELP.

 

[1EVIL88VERT]

well for me it was just ease of tunning to go to mass air ....more available, and i was able to do the swap for about 200.00$ so it just made sense to me. Their are alot of guys on this site that swear by speed density though, maybe one of them will chime in on this.

 

[HISSIN50]

With MAF, it is more able to accomodate changes, and vac signal is not as critical. For SD, one would need to tune more often after mods. There are a lot of SD cars making mad power - the MAF swap is just easier for some folks.

 

[DMAN302]

SD is controlled by vac to a great extent..as HISSIN50 pointed out. SD is a great system when it's working well with the cars components, but changing injectors, adding a cam (though there are a selection that will work well) can cause the car to run like a spoiled child. In my case the addition modifications left me with a surging stalling rich running pig...it was about as much fun to drive as 82 k car. Once the conversion was complete the car was able to accept and adapt to the components added...result was a fantastic running automobile. You can stay SD and see what happens, some cars will act up..others will not.

 

[NakedRaygun]

Yeah if you want to keep SD just have all of your parts put on at once and get it burnt.

 

[90bronconate]

i dont fully understand why maf is better than speed density??

what i've heard people say and what i've read on here by people that i regard as knowlegable on the subject is that SD is better when drivability is not an issue. as in a car that is stricly a track car. the guys who run SD for their track car don't use it as a daily driver so all they care about is WOT performance. if you want a decently modified daily driver, you'll be much happier with Mass air.

 

[90mustangGT]

Speed Density works with a mathmatical equasion taking a reading from the MAP, MAT (AIT), BAP, 02, and an input from the EGR position sensor and TP sensors, and takes in consideration of the Volumetric Efficiency and comes up with a number and uses the Engine Parameters stored in the ECU to figure out airflow so it can properly meter fuel. Adding parts which would mess up that equasion without changing the parameters and your looking for trouble.

A mass air system in our cars uses the MAF to determine all airflow, which is not effected by other parameters. then uses the AIT sensor to detect density and then uses EP.

 

[txstang84]

SD cars with a baro press sensor?? I still have yet to see that one...map yes, bap-haven't seen that one unless you're running a stand alone system

 

[89MustangGX]

I think in all actuality, SD is probably a better idea. But Mass Air is definitely more friendly when it comes to just changing a part and starting the car.

All things being equal, they probably really are equal. But most people find it more cost effective to go mass air and change whatever parts they want than to have a custom SD chip burnt and reburnt any time a change is made.

 

[90mustangGT]

SD cars with a baro press sensor?? I still have yet to see that one...map yes, bap-haven't seen that one unless you're running a stand alone system

I was talking in general, mustangs and fords arn't the only one's using Speed density. Many new cars still are using speed density, and most aftermarket EFI's also use speed density.

 

[txstang84]

I was talking in general, mustangs and fords arn't the only one's using Speed density. Many new cars still are using speed density, and most aftermarket EFI's also use speed density.

yeah, i'm aware of that, my wife's '01 civic is SD, and I've installed two different kinds of aftermarket FI systems (holley projection, and howell-both on a Jeep), and still have yet to see an SD system with a baro sensor

 

[HISSIN50]

I agree with Adam - I like SD better too. it can actually be faster with processing since it is using tables rather than a 'fuzzy logic' to guess at air flow. But if the reality of mods does not match the programming, issues arise.

Many stand alone EFI systems are SD - I like that. (SD is one step closer to a carb set-up from MAF. ).

 

[Joliver159]

Mass Air, Vs Sd

Ok I just got my 87 stang. I know I do not have mass air. the only thing i've done to my car is Exhaust, and i installed a T-56 Tranny. So that said why would i put mass air on my car? When i ran my exhaust I also cut the smog pump pipes. and took the belt off the smog pump. So can i take the smog pump off completely? am I hurting performance by running my car this way?
Thanks

 

[wildstang87]

my smog is deleted as well as the cat converters, and i havent had a problem. i think the previous owner installed a cam b/c it is pig rich with a little lope, but could be just the tune. my 87 only has 64k on it and it just doesnt run like it should.