Duh, the MAF outputs a voltage based on the resistance.

Because it is an exhaust restriction. The turbo requires positive manifold pressure in the exhaust side to produce axial torque. The resistance to mass flow requires the engine to expel torque in order to push the exhaust gas out. That is a pumping loss.

Compressor efficiency is essentially adiabatic efficiency which is also commonly refered to as thermal efficiency. It has to do with deltaT, so in that regard compressor efficiency is solely based upon thermal efficiency and heat of compression.

If you are talking about a K27/6 then you will find that the turbocharger will develop gains where it maintains boost pressure and the K26/6 falls off. The moment before this happens can produce a difference in torque due to an increased density of the air, which is solely related to a large compressor efficiency differentiation.

It should also be noted that the K27 compressor spins at a lower shaft RPM to provide the same airflow. This should be more advantageous for the turbine's efficiency point. Further gains in mass flow can be had, and a reduction in pumping losses will result (increased torque).

 

The air flow, or air mass, and temperature is measured before the intercooler. Well, before the turbo.

There is one plain answer to original question.

"When upgrading to a larger turbo is it necesary to go with a new set of chips? "

If you want to raise the boost: yes.
If you don't raise the boost: no.

Even if you're still within the AFM/MAF capacity you need new chips and the main reason for that is that the WOT timing map is fixed.

Timing is rarely discussed here, but it's "the" thing to care about if you want to run high boost.

 

Good post.

 

I guess Streckfu is naked on the corner, cause he's got no reply.