View Single Post
      08-26-2011, 03:49 PM   #17
bruce.augenstein@comcast.
Lieutenant Colonel
89
Rep
1,993
Posts

Drives: Legacy GT - 13.704@99.39
Join Date: Jul 2007
Location: Manheim, PA

iTrader: (0)

Quote:
Originally Posted by erhanh View Post
Yes larger intercooler will cause the boost to be lower, BUT lower air temp = denser air. The thing I don't know is the relation between boost, temperature and density.. What I mean is, let say the ambient temp went to 40C from 20C. We put a bigger intercooler that will bring the temp back down to 20C.. Do we need a 2x bigger intercooler? If yes, is the boost half due to 2x larger intercooler? What happens to air density at the end?
There is no direct relationship between intercooler size and "pressure drop", although the more efficient the intercooler is, the greater the drop between its inlet and outlet, for obvious reasons. No matter, though. They just crank up the boost so the engine sees whatever the manufacturer intends. Overall result with a bigger/more efficient intercooler is denser air at the throttle plates at the same boost level.

However, no intercooler is 100% efficient. Not even in the laboratory. About 75% efficiency is as good as it gets.

Drag racers get around this with liquid intercooling, stuffing the system with ice. Presto, temps at ambient or below with full boost and max timing.

Bruce