MAF voltage

[Rocco]

hi mates

stock and RS4 MAFs are 0/5v ?

when the stock MAF will reads 5V? i mean,is it related with engine flow and then HP? so if this is correct,the 5V read would be around 400Hp?

or how it really works?

RS4 MAF would read 5v around 650Hp?

[driftin jo]

I think it tops out at ~330 HP, ask Prj, he will know for sure.

You also program/calibrate the ECU to read X flow(HP) for a given voltage,
i.e. you could have it read 300hp at 2.5 volts, although the resolution would be low
and thus not very accurate.

The RS4 MAF will read 5 volts at a much higher flow rate.

[Rocco]

thanks,Dmitri will answer then (if he is not busy like the last times)

[Nuno Cristiano]

In RS4 not remember well but this week i worked in BAM 1.8T and originally MAF SENSOR can read 1200Kg/h ( 333g/s ) @ 4.8V.

[prj]

The stock maf is not 0-5V. It goes up to 5.7V.
Does not max out at 330hp, maxes out later. IIRC like 380 or so.

The RS4 MAF is 0-5V with a 5V reference, and 5V at sensor according to the calibration data in the Audi RS4 is 499 g/s.
Using the 80% rule this is approximately 620hp.

But I think it's a bit too optimistic.
The more HP you try to extract from a small displacement, the less efficiently you are using the air. Also it depends a little on how the MAF is installed in the air stream. If it is right after the filter then that can have some effect on the reading.

So on an Audi I5 engine, I have maxed out the RS4 MAF a few times, and usually happens at about 550hp. But depends...
There is always the HPX maf for very high power applications. This can read a lot more air in a 3" tube than a RS4 sensor and can be fitted on the pressure side.

I will probably use this MAF for a few high power cars, until I finish developing my MAFless solution on M2.3.2

[andy10v]

until I finish developing my MAFless solution on M2.3.2

Sounds interesting.

[Rocco]

DD, will you feed the M2.3.2 with RPM and MAP like a standalone?

[prj]

DD, will you feed the M2.3.2 with RPM and MAP like a standalone?

I am working on it. The MAP is already in the ECU, so it makes some things easier.
This means completely rewriting the load acquisition code from scratch in the ECU, but I think I can do it.
A bit worried with the accel enrichments though.

[pasbogdan]

You know you should be kept in a controled enviroment?Humidity,temperature,food and all aspects strictly monitored? )))))

[andy10v]

Are you doing this re writing as a challenge/hobby?

[prj]

Are you doing this re writing as a challenge/hobby?

I don't know what to answer to this