maf distance from turbo important?

[dvd]

Hi, i had a problem getting my car to idle when I first tried to start up my ca18det in my 510 2 months ago. Then i read somewhere that I should have at least 18inches of space between the turbo and the maf. So I decided to get a 90degree pipe I had left over and used it as the inlet pipe. Sure enough the car idled! In the end, i didnt have enough room in the 510 to put a long enough pipe between the turbo and the maf so I just put the maf in the coldpipe side for a blowthrough maf set up. But i'm wondering, I've seen pictures of people using a coupler to attach their maf to the turbo! WITHOUT ANY PIPES INBETWEEN. I'm curious, was(or is) my maf going out(ka sohc maf) or something else?

Thanks.

[biosehnsucht]

What sort of MAF did they use? MAFs are notorious for being picking about airflow, some of the big honkin' MAFs that have a sensor stuck in the middle of the airflow may be less problematic, but definately the KA style ones that have a small side hole for the sensor are going to be very sensitive to uneven airflow through the MAF

[Reno]

How bout the Maf near the TB?? feasible?

[c-rad]

How bout the Maf near the TB?? feasible?

Same problem... tb plate slams shut, air gets reversed through the maf when the BOV opens...

[Reno]

hmmm thats true...

[float_6969]

As bio said, unless they were running some sort of aftermarket MAFS, I don't see how they had it functioning properly. There HAS to be some space between the MAFS and the turbo. If it's too close the air is too turbulent and throws off the reading.

[datsunboy]

I can definately confirm that.we had lots of problems with my mates CA18 datsun 1200 coupe. it would run rough, and really rich, untill we shifted the MAF into the guard/wheel space further away from the supercharger. ( 1200 engine bays, are tiny, and thats the only place we could move it to )

[float_6969]

If I understand the principle correctly, the turbulence removes more heat from the hot wire than it should, causing the ECU to generally think that it has more air than it should and makes it run rich. It also isn't a consistent reading and can make it fluctuate from rich to lean. Turbulent airflow+MAFS=BAD. That's why most manufactures place the MAFS DIRECTLY after the air filter. The filter evens out the air flow. It's also almost always placed as far from the motor as possible.

[davidricardo86]

If I understand the principle correctly, the turbulence removes more heat from the hot wire than it should, causing the ECU to generally think that it has more air than it should and makes it run rich. It also isn't a consistent reading and can make it fluctuate from rich to lean. Turbulent airflow+MAFS=BAD. That's why most manufactures place the MAFS DIRECTLY after the air filter. The filter evens out the air flow. It's also almost always placed as far from the motor as possible.

So if you wanted to run maf the correct way, it should be more like this right(factory setup)?

[biosehnsucht]

correct.

[dash]

maybe the custom ecu map allows this one. 338hp[IMG][/IMG]quite a few blow-thru z32 afm setups out there making power.

[c-rad]

quite a few blow-thru z32 afm setups out there making power.

Yeah, but they run it in the cold pipe away from the TB and BOV.

[400whps13coupe]

turbulant air throws the maf off period. mafs read air both ways in and out thats y they recommend running your bov back into intake if throttle body is shut the released from bov travels back through the maf in reverse letting the engine know to cut the fuel for that amount of air.

[Buddyworm]

turbulant air throws the maf off period. mafs read air both ways in and out thats y they recommend running your bov back into intake if throttle body is shut the released from bov travels back through the maf in reverse letting the engine know to cut the fuel for that amount of air.

False.

They recommend recircing BOV's because they release air AFTER it's been measured by the MAF which throws off your air fuel ratio. Plumbing it back into the intake pipe after the MAF keeps the same amount of air in the system.

You're correct in saying that the MAF reads airflow in either direction but it can't distinguish between them. Which is why turbulent flow is bad for MAF readings: Regardless of which direction the flow is going the ecu still reads it as airflow INTO the engine and adjusts fuel accordingly.

[zombieslider]

i know this is way off-topic, is that an sr torque dampener?

[Kalypso]

as long as its on the hot side, before turbo inlet, you prevent oil and blow by from getting into the maf.

that is all

[float_6969]

Necroposters. All of you, nectroposters! Thanks for searching though.