Dbeck002

it just occured to me now, why cant i port the stock maf sensor? there is plenty of meat to cut away and i could get it to a good 70mm with a good porting bit, save me 120 bucks... what do you say..

mdvaldosta

You can port it but you will run lean, you will need a tune or at least an adj fuel press regulator to get your a/f back right

Dbeck002

i dont understand, what is the difference between an after market maf and a ported stock one? they are both calibrated to 19lb injectors and will flow the same.

mdvaldosta

hmm.. ok here's a maf class. maf's measure airflow by two calibrations.. air temp and air flow. your iat lets the ecu know the temp of the air to determine density, and the flow of the air past the maf post containing a heated wire (the heated wire takes a certain # of volts to keep its temp constant - the more air flowing past the meter the more volts are required to keep the wire at the specified temp). Now, the meter is calibrated to the volume the tube can hold. If, hypothetically - I don't know the exact measurements for your car, you are at 3v the ecu will look up the timing and fuel charts and assume that you are getting 500cfm of air through the meter and add the appropriate fuel and timing...

now... because of your porting you are now running 550 cfm of air into the engine... but the ecu things its only 500 so its sending the wrong fuel (less) and wrong timing (more)... which means loss of performance and potential detonation. You have to understand the maf only "knows" how much air is coming through it as long as it knows the size of the sampling tube. The reasons the aftermarket tubes work is because the sensor wire is calibrated to the size of the sampling tube...

So in order for your gutted maf to work you would have to either increase fuel pressure to get more fuel through the injectors to compensate for the additional air (this whole while your ecu is none the wiser... so your timing tables will suffer), get your maf re-calibrated (might as well buy a new one than go through this), or get an ecu tune.

Hope I was clear, its getting close to bed time.

Dbeck002

i understand.