This piece of work is " The Scavenger".
Made by a RV dealer, no less.
What does it do? Apparently it's magic. They claim it increases horsepower and torque by a huge amount by sucking the gases out of an engine. How much? Well, if you believe their dyno charts, a chevy 454 gains over 70 horsepower and over 100 ft/lbs of torque. Wow. Like I said, magic.

Basically, they've taken the "bilge pump supercharger" idea sold for years to and from morons on Ebay, attached it to the tailpipe and are making the same claims. And, like the "supercharger", a squirrel cage blower cannot even hope to keep up with the sheer volume of gases pouring out of a decent sized v8, it ends up being a restriction in the flow no matter how fast it spins.

Go see it for yourself.