Okay....it's been a long time since I've actually had to make calculations....it's not that hard, but figuring out how to do that square root thing was not easy! :-)

Anyway, with a centifugal blower, the blower speed squared is proportional to blower pressure.

So at redline (6200 RPM), you have your max boost.....at half redline (3100 RPM), you have 1/4 the pressure (half speed) because of the squared relationship.

This curve represents an ideal Pressure Ratio (ratio of desired HP to existing HP) of 1.33.

The Audi specs all state that the KW is 220 at 6,000 RPM for the ABZ engine, which correlates to 295.02 HP from my calculations, don't know where they get 300 HP. I have used the KW numbers converted off a graph of the ABZ engine for this chart.

Note that the power now goes up from 6000 RPM versus down because of this squared relationship.

<img src="http://www.audipages.com/upgrades/supercharger3.JPG">

I haven't run the numbers yet, but I think it's going to be hard to get any more than this out of an ABZ engine which is at 10:8 compression ratio (CR). It will need to be intercooled.

But I think the curve looks great! Around town in normal driving it will be like stock and have all its torque, and when you give it gas.....it's gonna go once it gets above 3,000 RPM!!!

My spreadsheet shows stock HP 295 @ 6000 RPM (292 @ 6200 RPM) and supercharged HP as 385 @ 6000 RPM (388 @ 6200 RPM).

pw