I have a few questions just out of curiousity. My knowledge base in this area isn't deep so feel free to fill me in with the correct info.
I know a Mass Air Flow sensor converts the amount of air drawn into the engine into a voltage signal and the ECU needs this information so it knows injection duration, etc. I know a MAF im principle operates by using a thermister, power transistor, and a comparator.
I'll try to break all the questions into bite size chunks.
1) What does the car have in stock form? A Vane Air Flow Meter (potentiometer, return spring, etc)?
2) Both types output a voltage/air mass curve. How do you know what kind of curve the stock ECU is expecting?
3) If the curves don't compare nicely, how do you know you're not telling the engine to use too much or too little fuel? I'm assuming you have to rewrite the ECU's fuel curves?
4) If not rewriting the ECU's fuel curves, how are you converting the MAF's output voltage curve into one that the stock ECU can use?
5) If you are rewriting the ECU's fuel curves, are you using megasquirt?
6) If rewriting the fuel curves, how do you know what a good fuel curve for the M42 is? Is it a trial and error thing or is there an easy ratio that you always try to obtain?
7) What makes the MAF so much better than the stock sensor? Will it respond quicker?
What is that MAF from?
It looks like an interesting senior project. Nice work so far.
My senior project wasn't as practical. It was sponsered by a company who makes transducers and I used a bank of different frequency narrowband transducers to send out an ultrasonic signal and then monitored for a response. I then did an analytical cross correlation between the output signal and the received signal. With that and the speed of sound in the medium (which was air at this point), I could calculate the distance. If there was more time I would have added hardware that would allow it to calculate it's own sound of speed so it could be placed in any medium (water, air, thin air, dense air, space, etc) and it would accurately calculate distance. It used 4 pairs of transducers with the lower frequency ones calculating long distances and the higher ones doing short distances. The system would automatically pick the most optimum frequency transducer for the distance.
It was a good project overall and included a lot of electrical engineering aspects including signals, power electronics (transducers need to be fed hundreds of volt pulses), filter design, digital electronics (I had an FPGA doing system controlling, buffering data and having it accessible to a uP bus for a CPU), and software design.
Senior projects are fun when they're over
