Power-adders
      
      Internal combustion engines require air (oxygen) 
to burn fuel, and therefore increasing the air flow 
into the engine will theoretically increase 
performance.  The process of combustion creates 
a vacuum that naturally draws air into the engine.  
However, increasing the flow of air, or boost, is a 
primary method for increasing horsepower.  This 
is accomplished through three main methods: 
chemically with nitrous oxide or mechanically 
using air compressors.  
      
      Nitrous oxide is a gas that when introduced into 
an engine creates greater combustion through its 
increased oxygen content.  Combustion 101 
dictates that you need oxygen and fuel 
compressed and ignited to produce power.  
Nitrous oxide contains a greater proportion of 
oxygen than does normal ambient air.   Nitrous 
oxide is bottled under pressure in liquid form and 
introduced into the engine through small high 
pressure nozzles at wide open throttle.  The 
nitrous gas mixes with the fuel and combusts with 
much greater intensity than the ordinary air-fuel 
mix, creating much more horsepower.  While this 
sounds like a perfect horsepower solution, nitrous 
has several key limitations.  
Primarily, nitrous takes up a lot of space, a single 
2 liter bottle may only provide enough gas for 2 
quarter mile passes at the drag strip.  Mounting 
any more than 2 bottles in a vehicle and the 
weight begins to affect performance and offset 
some of the gains.
Nitrous also isn’t free, the way air is—Nitrous 
prices are approaching $8.00 to $10.00 per 
pound, for a 10 pound bottle- that’s $80 to $100 
for a few passes down the quarter mile.
Finally, the more powerful combustion creates 
more strain on engine parts, increasing the 
likelihood of failure.
      
      Nitrous Oxide
      
      A supercharger is simply an air compressor that is 
driven by the engine crankshaft (via a belt) similar 
to the way a water pump works.  Like a water 
pump, the supercharger spins continuously, while 
its speed varies with the engine RPM.  This direct 
link is what makes a supercharger desirable; the 
instant the engine RPMs rise, more air if forced 
into the intake manifold by the supercharger, 
instant boost.  
The downside of this design is the supercharger 
cannibalizes some of the power created by the 
engine to create boost.  The marginal horsepower 
created by a supercharger comes with a 
proportional cost.   This effect is particularly 
unfavorable at low RPM when boost isn’t 
necessary but the supercharger continues to draw 
away horsepower.  
      
      Supercharger