A well designed Water /Air intercooler keeps the Intercooler
component very close to engines turbo & air inlet, so as to
minimise any lag introduced by excessive piping. A big advantage
of the air-to-liquid setup is the lower overall pipe and intercooler
length, which offers faster response, giving peak boost faster.
Water / Air intercoolers are more complex than Air/Air intercoolers,
as they require more components. A Water / Air essentailly consists
of 3 major components; 1: Intercooler 2: Heat Exchanger / Radiator:
3 Pump. A Water/Air intercooler works by transferring the
charge air heat (from turbocharger or supercharger) to a liquid
coolant, this coolant is then pumped to heat exchanger (Radiator)
where ambient cooling air removes the heat. The heat exchanger
can be positioned remotely from the actual intercooler, allowing
for an increased flexibility in component positioning.
The pressurised air (post turbo) passes through the charge cooler,
transferring heat into the liquid coolant. This liquid is then
transferred (pumped) to the heat exchanger that absorbs and transfers
the heat to the atmosphere.
Water / Air intercoolers offer the ability to transfer significant
amounts of heat from the charged air. For this reason, it is critical
to have a properly sized system, as any heat removed from the charged
air is transferred to the liquid, and must then be removed from
the liquid back to the atmosphere before the liquid travels back
to the intercooler. If either the intercooler, or the heat exchanger
are undersized, it will result in sub-optimal performance.
The heat exchanger can be mounted in the most appropriate location,
given the vehicle constraints. Vehicle speed can be used to cool
the liquid, or a fanned heat exchanger used, or a combination of
As liquid has the ability to absorb more heat energy than air,
it tends to offer very effective cooling for short burst WOT. If
a vehicle is constantly running under boost conditions, the liquid
can become warm, reducing the effectiveness of intercooler. Most
street driving has short acceleration activity, and more sustained
cruising, allowing the liquid to cool considerably during this
Low speed applications often benefit greatly from Water
/ Air intercoolers, as are are not typically as relilant on vehcile
speed to maintain there colling capabilities.