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Speed Density Vs. Mass AIR?

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Old Nov 11, 2000 | 09:08 PM
  #1  
leirch's Avatar
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Speed Density Vs. Mass AIR?

Guys, i have a question. Now, i know Speed density is sposed to be by FAR a better system then mass air right?
Well i have a brother that for some reason is a mustang 5.0 ***, yea.. i know. he went to the dark side
oh well, gives me something to make fun of him about.
Ok but anyways, in one of his motorsports books the mustangs used speed densisty from 85-87 or whatever then they switched to mass air?

So my bro is telling me that mass air is better and i'm like, HORSE ****....
Could somebody please clear this up?

Thanks for any help/comments,

Brendan
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Old Nov 11, 2000 | 09:37 PM
  #2  
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The Speed Density 5.0s are faster than the MAF 5.0s... the Speed Density TPI cars are faster than the MAF TPI cars.

As to which is better... MAF is more forgiving of high HP mods, while SD takes well to most minor mods... anything short of a radical cam or heads.

------------------
91 Trans Am WS6
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5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

supposed 'peanut cammed' car (yeah, right)

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Old Nov 11, 2000 | 10:56 PM
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From: In a mint Third Gen!
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Go here http://www.racer-x.f2s.com/proc/tpi2.htm and go to the MAF section.

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Old Nov 12, 2000 | 12:09 AM
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They both have "goods" and "bads". It's a lot easier to tune an SD system then a MAF system for example. MAF will be able to better "self tune" if you make any modifications that increase air flow. SD will not be as forgiving. SD cars were quicker in 91-92 because of minor cam changes and the addition of dual cats not because of the SD system itself.

------------------
92 Z28 L98 350
---------------
Ported and polished heads, ported stock TPI base, ported plenum, Comp Cams XR270HR-10 cam (lift .495/.502 duration 218/224 lobe separation 110), Edelbrock TES headers, LT4 valve springs, Crane AFPR, Flowmaster catback with LT1 style tips, MSD coil & wires.

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Old Nov 12, 2000 | 02:56 PM
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Car: 1990 Pontiac Trans Am
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They had dual cats in 89 too, a MAF year.

------------------
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Old Nov 12, 2000 | 08:18 PM
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Not all Speed Density cars have dual cats. The single cat TPI cars from 90-92 are faster than the 85-89s as well.
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Old Nov 13, 2000 | 01:08 AM
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The '86-'88 (except ones for California) Mustang 5.0's were Speed Density. Speed Density is faster stock (keyword: stock) than a Mass Air car. One because Speed Density cars go by set variables to determine the fuel/air ratio because it "guesses" how much air is coming into the motor and doesn't have a restriction of the air flow like a mass air sensor, whereas a Mass Air car and directly determine how much air is coming into motor because it has a mass air sensor to measure how much air is going into the motor. 5.0 guys go to Mass Air because once you start adding mods like cam or forced induction (i.e. Supercharger, Turbo, etc.) the computer will know how much air is coming into the car nomatter what the mods. If you add cam or forced induction to a Speed Density car it will screw up the set variables the computer runs off of and you'll idle like crap and run like crap (unless at WOT). Hope that clears it up for ya.
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