[freebeard]

If you don't mind occasional explosions, contemplate the Turbonique:

iowahawk: The Real Acme

At the mild end of the Turbonique product line were its AP (for "Auxiliary Power") superchargers, so named because they had their own power supply. Unlike regular superchargers (driven by a crank pulley belt) or turbos (driven by exhaust pressure), Turbonique AP superchargers operated independently of the engine and scavenged no power from it. They appeared to be a spiral turbo with a spark plug, and were engaged with a dash-mounted switch - a sort of prehistoric Nitrous setup. When the driver threw the switch, the supercharger unit would receive liquid oxygen for ignition, and then it was fed a rocket fuel named Thermolene -Turbonique's trade name for N-propyl nitrate. The exhaust thrust from combustion would spin a turbine impeller up to 100,000 RPM, ramming the engine with such intense boost that it essentially turned it into a giant two-stroke. Turbonique dyno-tested an AP unit on new Chevy 409 in 1963, increasing horsepower from a stock 405 to 835 -- backing up their advertised guarantee to "double your horsepower" -- although it came with a recommendation not to run the unit for more than 5 minutes and only with forged cranks, pistons and connecting rods.

Emphasis mine, it's worth the read. Also Turbonique News, Videos, Reviews and Gossip - Jalopnik