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Speed-Density VS Mass Air


blue98ls1

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In my opinion you would first have to know; not understand but know how

a Mass Air Sensor (MAF) and a Manifold Absolute Pressure(MAP) sensor

works. The bottom line is accurate fuel control. The best means of

measuring airflow is through a MAF. This would be for steady state and

light throttle transitions. A MAP sensor works exceptionally well for

sudden changes in engine vacuum or throttle angle; maybe this has

something to do with it being plumbed directly into the intake manifold.

Now, the perfect scenario would be to utilize both in the same operating

system; and most people who argue this controversy overlooks that Ford

and GM has incorporated this logic a long time ago. Early GM using a

physical MAP sensor and Ford using an inferred MAP calculation. Now, GM

like Ford even uses an Inferred / virtual MAP calculation. So, have you

driven a Ford lately? Most software programs put this virtual MAP logic

in Lames terms, so most users don't even understand the complicated

logic used by GM. I took time to understand the entire calculation and

converted it into an Excel spread sheet a while back; so I will be the

first to raise my hand and say its a pain; and really that isn't

everything, wait till the cams move. For the sake of simplicity the no

vice software has my thumbs up. Most recently Honda has even traveled to

the dark side and incorporated the MAF logic. That should tell you

something if there doing it across the pond.

 

 

 

So in my opinion there contribution to fuel control both have there

uses...but remember the OE's put MAF's on there for a reason. However,

having the correct resolution during fueling is also important...so in

GM world the only way to get the best resolution in boosted application

where the MAF will peg or run out is to go SD with a 2-3 BAR MAP;

unfortunately when this is done you give up the MAF logic. I hear alot

of people refer to "why is SD used in race cars then"; well almost every

aftermarket system out there that you would see in drag cars don't have

MAF logic.

 

 

 

If you have a NA car or a car that will not peg the MAF keep the MAF you

will have the best of both worlds. If your forced to head toward more

resolution...well sometimes it is what it is.

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