Turbocharging & Nitrous

Turbo's make more power by forcing more air into your engine so more fuel can be burned.  They are driven by the engines exhaust gasses.  This "turbocharging" works but has one or two problems.

• If the turbo is small enough to "spool up" at low engine speeds it becomes a "restriction" of the exhaust gasses in itself.  This limits maximum power severely.  An engine cannot flow air in if it cant get rid of its existing gasses!
   

• If the turbo is sized large enough to allow a reasonable maximum power output without the turbo itself becoming a restriction when "on boost" then there is a problem called "LAG" at the low RPM end of the spectrum...  This is because the engine does not make enough exhaust gas at low RPM's to spin the turbo fast enough to make any "boost" pressure.  Boost pressure is self sustaining however, in that if you could spin the turbo up at low engine RPM's the boost itself will then cause enough exhaust gas to spin the turbo!

Now, if we use a little Nitrous Oxide injection, at Wide Open Throttle (WOT) condition, the engine will make power instantly! Then even at low engine RPM the turbocharger will spin up because of the exhaust gas produced!  Now a small pressure switch in the inlet tract sees the pressure, and turns off the Nitrous Oxide.  The boost is now self sustaining.  Little Nitrous is actually used in practice.  The result is a lag free turbo system, even if a huge turbo is used!

Nitrous Injection, and large turbochargers were made for each other.

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