On the MY00 WRX GT hot wire air flow meter, does anyone knows what is the high limit that it can measures in terms of cfm?

Has anyone max out an AFM before? and on what turbo was that?

keet

 

Depends on how it is calibrated - ie what airfilter you have on it and if you can reprogram the ECU's MAF scaling.

I've had 406 BHP on conservative rollers and there was still more MAF voltage to come (was about 4.76V IIRC). This was lowered by about 0.3 V because of an APS induction kit.

I am still thinking about a speed density conversion as per my thread on 22b, just not had time to do it. This would remove any limits.

Of course the simpler option is to fit the hot film MAF into a larger diameter tube to get more airflow capacity but you need to be able to remap the ECU to do this.

 

In std trim without access to ecu maf scaling, the std maf housing can more or less "reads" 600cfm (~your 406BHP )? right?

So the std maf housing may be the first bottleneck before the maf itself...I did have thoughts before to remove the protective mesh at the front of the maf though!

keet

 

The problem is without access to the ECU mapping, you will maximise the load zone access at about 1 bar on a large turbo and standard induction.

If you remove the mesh and use a larger tube then you will advance and lean out the proceedings and encourage detonation.

For what it sounds like you want to do, you really want programmable management, preferably MAP based.