I'm new to this forum and cant find a thread explaining the difference and powergains for each at the rear wheel.

What is the difference and the estimable powergains between the three of these chargers.

Thanks for any input.

 

Welcome! And get ready for the debate.
A supercharger is basically an air pump that forces the A/F mixture into your cylinders. It is powered by belts or gears turned by the engine itself. Since it uses HP from the engine to turn the pump, it is called "parasitic"
A turbo is an air pump that forces the A/F mixture into your cylinders. It is powered by a turbine which is spun by the exhaust gases from the engine. It is not mechanically connected to the engine, so it does not rob power from the engine.
A procharger is a type of supercharger known as a centrifugal supercharger for the way it spins the air and uses centrifugal force to create the boost pressure. There are several other types of superchargers, and this forum debates the benefits of each one vigorously.
Spend a day and browse through this forum and you will find more info than you can digest, and probably come away with some sort of opinion which is best for your particular taste, needs. Good Luck
HP gains will depend upon the set up, each can often exceed the other based upon that setup. I believe the turbo has the ability to create the greatest amount of boost.

 

The sticky thread "dyno graphs post them here" at the top of this forum will show you a lot or RWHP measurements for various kits.

No matter what, we'll all agree that boost is better than no boost. Whichever setup you choose will be faster than stock.