[ffindling]

Dragsters don't require intercooling for
two reasons: a: They don't use gasoline
for fuel, b: they use an extremely rich
mixture. Alcohol and nitro/alcohol blends
used in such engines are far less prone
to detonation and they dump vast quantities of fuel into the engine which
provides ample cooling of the intake charge. Obviously, the dragster
approach is only practical for dragsters.
As you are aware of, compressing air
puts heat into it (Boyle's Law) and to run
any meaningful amount of boost requires
that the heat (at least a good part of it)
be removed before the air is fed into
the engine's induction system. Even a
modest amount of boost will raise the
temparature of the compressed air considerably over ambient. 5 PSI will
probably raise the temparature 100F
over ambient. Feeding that hot air into
the engine will invite detonation, especially with pump gasolines which
by their nature are detonation prone.
Retarding ignition timing may reduce
detonation, but you could very well
end up with a net loss of power compared to a normally aspirated engine running at full advance. So intercooling is pretty much mandatory
for gasoline engines running at full advance.



....Fred