How much boost a blower makes at a given drive ratio is going to be determined by many things. More boost does not always result in more power. For example a motor with stock heads and cam will have higher boost, but make less power than the same motor and blower will make with ported heads and cam and less boost.
When it comes to blower porting, the inlet side of the blower is much more important than the outlet side. Bigger air filter, intake pipe, mass air meter, throttle body and inlet plenum will make the blower more efficent and produce more boost at the same blower speed, and that is where the power comes from.
Jacking up the boost by spinning the blower faster just consumes more power off the crankshaft to turn the blower and also ends up producing more heat coming out of the blower. Hot air expands and make boost number even higher, but pumping hot air into the motor kills power because it doesn't contain as much oxygen. It's all about getting the most oxygen in the cylinders, because the more oxygen you have, the more fuel you can burn. Burning more fuel is how you make more power. This is where the bigger intercooler, ported heads and bigger cam really helps.
Changes on the exhaust side of an SC motor don't show nearly as much gains as changes to the intake side of the motor.
David
PS: I don't think the pear shaped outlet is going to do anything to improve blower performance, and may actually hurt it.