Hey M Jack, this is ones for you the local engineer

I was thinking for a while about tinkering with an idea about getting rid of the MAF.

My idea is pretty simple really I just need to know more how the MAF signal works. This is my thoughts.... our cars really only need a few things to simulate the MAF, obviously some sort of an air count, barometric pressure, and temp (I think). So.... a temp sensor is obviously easy, I wouldnt think the barometric pressure thing would really matter for most of us unless we live in a mountainous area and even then it may not matter that much... just make our maps look alot different than others. As for faking the MAF reading I would think it should be pretty simple. If it just uses a simple voltage obviously any MAP sensor could be used (And may need a small electric board to jump or drop some of the voltages but as long as it is somewhat linear I would think it would work). The ramp rate and things may be WAY off but with a simple board I would think you could get it close but even if you were lazy and did not want to get the ramp rate and everything close you should be able to just tune it all out with the open loop fueling I would think. The downside would be you could not really have ANY spots where the stock ECU controls anything and all the stock ECU values would become worthless (So for those who use ECU timing VS knock reading to see if it is 'true' knock wouldnt work). But honestly... doesnt this seem like a perfectly fine idea??? I cant see why it wouldnt work out fine. And otherwise.... perhaps it would be easier to read the straight voltages that the MAF produces through the wire/sensors.... and just rip the MAF apart and use a map sensor output its voltages to right behind the stock MAF sensor (Internally). I would think it is a very small amount of voltage from the little wire guy to the actual MAF board. Therefore, with perhaps the right resistor you could just take the output from the MAP sensor, use a small resistor and feed it to inside the MAF sensor? Anyways... something along these ideas seems like it should work fine. Let me know what ya think!

 

I'm a little tired, so I'm not quite following everything at the moment.. but speed density needs Air temp, Map sensor, TPS..

The stock MAF sensor is a square wave signal (the HZ output of the sensor) so you'd need a karmann converter..

If you can find an HKS VPC for a 2g DSM, or check out www.mapecu.com which has a pretty good explanation of how the conversion works..

Basically, you would use TPS, MAP, AIT, RPM in the case of the MAP-ECU and VPC it uses a lookup table to create a karmann signal output compatible with the stock ECU..

Unfortunately I think its not quite as straightforward as just faking the unneeded signals, (the GM MAFT fakes the AIT signal)

Ultimately, anything is possible, but so far the only two products that I've found works well without switching to a complete standalone, is the setup I'm running, or the MAP-ECu, unfortunately they both were pretty expensive.

 

Nevermind then.. Figured it was worth a question about though.