Questions on a turbo's output


Believe nothing you hear and half of what you see.
Dec 9, 2002
I trying to get a better idea of what the output of a turbo is as the manifold pressure increases. Does the volume and pressure value increase in a linear way or exponetially? In other words, say a stock turbo is at 16 psi. The volume and pressure are X and Y. As the manifold pressure goes to 20, does the volume and pressure increase at the same rate to 20 psi? If you change the turbo to an aftermarket one, do they behave in the same way or is it a function of the compressure wheel? Is this what the "turbo map" is showing? I'm probably not explaining my question right but maybe someone can see what I mean. I also imagine the senario would change if you put a freer flowing intercooler and throttle body on. Thanks.
V8Killer lent me a book called Maximum Boost by Corky Bell. It seems like the info I need will be in that.
Flow is not linear, like a lysholm or positive displacement pump.

Creeps up to the "sweet spot", then flow climbs faster and faster with turbo rpm. Chart looks like a skateboard ramp.
So, not very good to be running a big turbo under the sweet spot. It would be a turd.