Very Important Considerations **PLEASE READ**

[DRAG Boosted Si]

No matter how much additional air is forced into the engine, no additional horsepower will be made unless additional fuel is also added. Remember, the energy that makes horsepower in an engine comes from fuel, not the air. In general, every 2hp produced requires 1lb of fuel per hour (or .5 pound per horsepower). When modifications are performed that increase airflow into the engine, more air is available for the combustion of fuel. The combustion of the additional fuel is what translates into additional horespower.
Supercharger and Turbocharger system manufacturers spend a great deal of time make sure thier systems offer reliable performance. Reliability can be questionable when modifications are made to boost levels raising the chance of engine-damaging detonation. Fuel quality, the engine's compression ratio, and total ingnition timing limit the amount of boost that can be run without detonation; exceeding the limit can result in a piston-melting, lean fuel condition or in detonation (where the fuel uncontrollably explodes in the cylinder causing possible engine damage).
Remember, supercharger and turbocharger systems from the major manufacturers are engineered to provide reliable performance when used as directed. when considering raising boost levels (which may not be emission legal in some states)always contact the system manufacturer for their recommendations. Talking to the experts will provide an extra measure of reliablity to ensure your ride doesn't take an extended vacation from the streets.