Using a maf from a 95 camry 1mzfe

[mr220v]

Its not the typical maf that has been used with most beams swaps, but seems to work. It looks like its the same basic mechanism as the normal beams maf. The main advantage is that its readings arent' contingent on the size of the pipe that it is placed in. I've seen complaints about running lean or rich due to this. It comes in its own housing already. I just had to repin my maf plug. I'll see if running this maf has any bad side effects.

Anyway, got the beams running for more than just a sputter and drove it around the parking lot with an open header. The ecu is running code free, and everything seems to be ok, albeit loud.

[Enthalpy]

Nice!

In doing Subaru MAF-equipped rechips with sensors similar to the 1MZ MAFs, I have learned something.

Airflow through the sensor isn't uniform! I knew this in theory, but it never really sank in. If you put a different filter on there that redirects the air to a different part of the MAF's cross-section (away from the sensor piece) then you can hit different AFRs.

The 300 ZX Twin-Turbo motors had the same issue when they placed filter cones on their MAF and put it behind the bumper. The air was so turbulent the MAF went crazy! The engine wouldn't run!

[mr220v]

I has to do with air velocity in this case. Put the sensor in a huge pipe, and the the platinum bits stay too hot. Put it in a tiny pipe and the bits stay too cold. Put it in the pipe toyota intended, and you get the correct reading.

Nice thing about this sensor is that it comes built into the pipe. You aren't stuck trying to find a beams airbox.

[Enthalpy]

Oh, I see what you are doing now.

All hotwires I know of have an internal controller that modulates the POWER to keep the element TEMP constant (as opposed to keeping constant power and measuring element temperature). The signal returned is the power consumption the element has.

If you are putting it in a small pipe like you say and the element actually gets cold, then you are outpacing the range of the sensor.

Perhaps there are hotwires that operate another way?

[mr220v]

No, you're right. I was over simplifying how it works. The reading is actually derived from the voltage needed to maintain the constant temperature.

[Weasy2k]

mr220v has it right...
and don't forget a VERY important detail....

Putting a larger maf on and engine it wasn't designed too and you will run into this problem (well its easily fixed but yea)
Larger maf = less flow through needed (velocity) = incorrect voltage reading = ECU believes you are at a lower then actually load and advances timing....

I don't need to fill in the rest :P

I have a smt6 in my Tacoma with a 2jz supra maf and i logged the OBDII system which PROVED right away that the ecu doesn't know where in the load range it really is and i noticed and increase between 3-5deg of timing over stock maf. Of course the truck hauls ass and the 5vz can take the added timing but i used the smt6 to pull back some timing up higher and in the low rpm high load ranges to keep things safe. Also had to do some fuel adjustments to.

Soo don't forget about timing

[mr220v]

Thats why nobody needs to take it as an established fact that this afm works. I suspect that it will. Later 1mzfe's afms are the direct replacement for the beams afm, and it was a perfect fit for the beams intake pipe. I still need to drive it around a bit to see what the fuel economy looks like.

I remember when I ran a camry v6 afm on my 20v, my fuel economy went to 18mpg.

[Weasy2k]

you could run a huge maf if you want...just get a piggyback to control the fuel and timing aspects
I switched from my stock taco maf to supra maf and my hp and tq went up 10whp just from the swap after i modded the timing back to stock.