I'm currious as to what the MAF and MAP control on LT1 engines. Is the MAF used to allocate the fuel and the MAP used to allocate the timing? Are there other functions as well?

 

http://members.aol.com/InjuneerZZ/ScanMast.htm

 

MAF measures (surprise!) mass air flow. The PCM uses this number to set the fuel flow, in an attempt to achieve the desired A/F ratio.

MAP is used as a measure of engine load. Engine load is critical to spark timing/retard, and defining the ranges of the long term fuel corrections.

In OBD-II there is a "diagnostic" routine that verifies the sanity of the MAF reading by doing the speed-density calculation and comparing the result to MAF reading. MAP is obviously part of the speed-density calculation.

 

Not exactly the same topic, but real darn close and I hope this hasn’t been beaten to death prior and my apologies if so…… I have concerns about tuning cars with aftermarket MAF’s and even the need for one.

Looked at my trims this morning and they are leaning the motor out some (11 and 13%). I spent quit a bit of time earlier adjusting the MAF tables to get the trim levels right on. Checked for exhaust leaks and all the basic stuff and even have a set of new 02’s I going to install just to make sure it’s not the 02’s throwing things off slightly.

However, my real concern is even the need for aftermarket MAF (only have the halves) at all. Anyone know how much N/A hp a stock LT series MAF will support??? Sure would make it easier to tune using a factory MAF and factory MAF tables but I don’t want to leave any power on the table.

Being I have unlimited access to a dyno I can test it myself but man…… what a hassle if I didn’t have to. My new combo should make 450 rwhp give or take some. Is the stock MAF OK?