Hello,

I am converting my Turbo 420a from the stock ECU over to Megasquirt 2 Extra for fuel and spark.
(Wasted Spark and Batch fire fuel if that is relevant)

I am curious on a few issues...

One, I have been looking for a GM IAT (air temp) sensor, but I have not had luck finding the thread in type at the junk yard. I found lots of rubber press in style, but no thread in ones... I think I'll buy one instead of junkyarding it, but that led me to wonder... why use the GM one and worry about threading it into the manifold when the stock setup already has a sensor? Has anyone used the stock sensor on megasquirt? Is it suitable for Turbo application? If so, are the calibration values available somewhere?

Secondly, and somewhat related... Can anyone let me know what ECU functions still remain on the stock ECU if I convert over to Megasquirt with full fuel and spark?
I believe it controls the alternator field, the air conditioning pressure sensor/clutch/fan, and (unless I rewire it) the speed sensor and speedo, and the Cooling Fan(s).
What other tidbits does the stock ECU handle? Does the stock ECU still use the IAT sensor for anything? (I realize it uses the CLT sensor for the fans)

If I steal the crank angle sensor, will I lose the built in Tach, or is that run from the cam pos sensor? I'll eventually run a tacho output from the MS, but just curious if the stock ECU will still have RPM after I steal the crank angle sensor for MS (My guess is no)...

Thanks in advance.