Quote Originally Posted by rrutter81
no that is exactly what im saying.

the MAP cells wont change because they are predictive calculations of the pressure inside of your manifold. Infact you would probably have to hit 50 PSI before you got off the chart.

The map sensor takes your RPM and the PRESSURE and calculates the fuel to add to it. The only time you are tuning it, is when your sensor is saying it is at a certain pressure when it really isnt. (eg porting and polishing). Even then your o2 sensor compensates during regular driving with LTFT and STFTs. After WOT it doesnt know what to think short of what the MAP says and THAT is what needs to be tuned.

All in all, if all you do is change a pulley, you do NOT NEED a tune. The airmass calculations are done unless you mucked with how much flow your getting....eg new intake etc.
Adding boost will change the MAF counts. When I ported my blower and had the same pulley, I DIDN't need a tune. I re-tuned it when I upgraded the injectors. When you go from 8PSI to 13-14PSI, you need a tune. I understand the tune is only for WOT purposes. The o2's controll averything at regular driving