Does anyone know how good these things work.

http://www.electricsupercharger.com/

You sir ARE kidding, right?

Does anyone know how good these things work.

http://www.electricsupercharger.com/

Actually they do put down some impressive numbers. Unfortunately, battery technology can't quite keep up. To will take about 10 minutes to get enough juice to charge a battery to pressurize a 4.6L motor to 5 psi for a 1/4 mile run. Of course you could always carry more batteries, which add considerable weight, or have numerous capacitators sequentially discharge.

This is actually an incredible idea, but it is still a few years out. Just think, a 4 hour install (probably also would want another injector and a water/alcohol injection system for safety) and about 446 hp (at 6 psi). Sounds pretty good to me.

Turbo Mag's install: http://www.turbomagazine.com/tech/0406tur_knight/
Thomas Knight's Site: http://www.boosthead.com/home.php

Bwahahahahahahaa!

Save up for a real supercharger.

My understanding is that these things are really designed for 4-cylinder cars anyway. For our Marks it would be like installing an extra propeller on the Space Shuttle boosters.