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I have a KLZE at 5 PSI... and my MAF (JE-50) is after the turbo (in the boost). Is it better to put it before the turbo? Sometimes when I start my car is run like if it was running on 5 or 4 cylinder... Is it possible that it's doing that because the MAF is after the turbo?

Nobody can answer to my question?????

It was to my understanding that the MAF should be in front of the turbo. I could be wrong, I was wrong once before.

Id put it after the turbo so the pcm can calculate the forced air

DiaMagus wrote:Id put it after the turbo so the pcm can calculate the forced air

That's a good point too.

The vane air flow sensor is an important part of an electronically fuel injected car... The pcm wont know the difference if you ram air in the engine past a sensor that helps calculate fuel trim and spark curves

In most applications where a maf or vaf is on the car stock it will be before the turbo. Look at the vaf location of the mazda gtx/gtr. Prime example

You put the VAF after the turbo before the air goes into the engine, make sure the blow off valve is before the vaf as well.

a proper boost setup you would eliminate the vaf and use megasquirt

Ok! my Blow off is after the VAF... can this cause a problem?

mx3autozam wrote:You put the VAF after the turbo before the air goes into the engine, make sure the blow off valve is before the vaf as well.

a proper boost setup you

would eliminate the vaf and use megasquirt

Please exlain why it goes there. I've boosted my car with stock oem gtx parts(yes I know its not a v6 but it does run a vaf as well) and the vaf is between the turbo and air filter. Not trying to say you're wrong just trying to figure out why it would go where you say instead of where the stock setip would be. I'm wanting to possibly boost my kl after I get it in and running proper and like to know for my own research. Also if you have pics/links to others that have boosted their kls with the setup like you said please post them.

turpro1993 wrote:

mx3autozam wrote:You put the VAF after the turbo before the air goes into the engine, make sure the blow off valve is before the vaf as well.

a proper boost setup you

would eliminate the vaf and use megasquirt

Please exlain why it goes there. I've boosted my car with stock oem gtx parts(yes I know its not a v6 but it does run a vaf as well) and the vaf is between the turbo and air filter. Not trying to say you're wrong just trying to figure out why it would go where you say instead of where the stock setip would be. I'm wanting to possibly boost my kl after I get it in and running proper and like to know for my own research. Also if you have pics/links to others that have boosted their kls with the setup like you said please post them.

Well if your maff is lts say on the intake side of the turbo, and your bov is on the throttle body side, it would cause a vacuum leak and the car would diw when the bov opens. In a recirculated bov, it doesnt do that or on a bov thats on the intake side of the turbo. At least thats what it used to do to me.

Well, The vane air flow ... as you all know works with other sensors on the engine. That send voltage to the pcm. via (12v) (Signal) (Earth) Usually between 2- 5vlts if the maf is unplugged the car will shut off if I remember. Why is that? Because the pcm is like "what the hell" and has no idea how much air is flowing. So anyways. UNMETERED air like pcv, turbos anything after the vane is going to be false air that the cpu cannot calculate because it has no idea its there.... I think that makes sense ... Meh cheers

MAF PRO. i know the basics of this system but not enough to dwell into it. however my friend was running a built and heavily boosted 7m gte 3.0 supra engine in his mark 2 supra and he had great results (until his cam snapped, on a non interference engine that had been decked so much it actually was interference....)




basically maf pro tricks your stock oem ecu into how much fuel to inject. it takes into consideration the amount of pistons, the engine displacement, the intake manifold pressure, intake mani air temp and speed density. all of this information goes and tricks your ecu into how much fuel to inject.

i guess the way that standalone works is when you tune your engine, every time you run your car it runs to the specs you punched in the day you tuned it. this is ok but on a hotter or colder day of the day it was tuned the engine wont run to its ideal settings.

sort of like a carbeurator. you tune it when summer starts to run to its best ability and you tune it again when winter hits so it runs to its best ability.

i guess maf pro tunes your stock ecu so many times per second, that on any day it will run to its best ability.\


again dont qoute me on this stuff, but im pretty sure thats how it works.

MAF PRO

DiaMagus wrote:Well, The vane air flow ... as you all know works with other sensors on the engine. That send voltage to the pcm. via (12v) (Signal) (Earth) Usually between 2- 5vlts if the maf is unplugged the car will shut off if I remember. Why is that? Because the pcm is like "what the hell" and has no idea how much air is flowing. So anyways. UNMETERED air like pcv, turbos anything after the vane is going to be false air that the cpu cannot calculate because it has no idea its there.... I think that makes sense ... Meh cheers

It's not gonna die with an unplugged MAF, the ECU will just run in open loop.

I think you need the VAF before the turbo since the VAF has no ability to measure density.

Here's my reasoning... On the normal, non boosted intake, the VAF sees atmospheric pressure on one side, and the vacuum of the motor on the other. I think the ECM also has a built in barometer to adjust for atmospheric conditions, as well.

On boost, if you put the VAF in the boost, it will see that exta PSI on one side, and not normal vacuum on the other side. The engine will be drawing air, and the turbo forcing it in. Although the consumption, from a volume standpoint, must be the same, and the ECM relies on calculating the mass from its internal barometer. This difference is density (mass). Once you boost, it raises the density of the air, and since density is very important to the A/F mixture, and the ECM cannot know that the vaf is in boost, it will throw you off...

Meanwhile, if you put the VAF pre-turbo, it sees the normal atmosphereic pressure on one side, and the pull of the turbo on the other. So during all normal conditions, aside from BOV opening, it will be reading the correct air.


Bah, screw it guys, just get standalone.