Difference between an Intercooler and a Radiator?

STirocket

Scooby Specialist

Member#: 84006

Join Date: Mar 2005

Chapter/Region:

NWIC

Location: Auburn, WA

Vehicle:

2005 Impreza WRX STi
WRB with Goldies

Turbo chargers...
The only thing I might add to this excellent discussion is how a turbocharger works just in case you don't know... There are two halves to a turbocharger, one side is in the hot exhaust stream, exiting the engine, which causes the turbine impeller blades to spin a shaft. The shaft goes through a bearing (cooled by engine oil, or water) and into another chamber where another turbine (connected to the same shaft) compresses the air that comes into the engine through the air cleaner. This forces more air into the combustion chamber than could normally be drawn in by the piston, which creates a vacuum (sucking fuel/air in) as it goes down in the cylinder. Some of the heat from the exhaust impeller is conducted through the shaft to the compressor, and consequently heats the intake air charge. The intercooler is between the turbocharger compressor, and as was said earlier, it cools the intake charge before it goes into the cylinder so you get even more fuel/air mixture than could normally be compressed by the turbocharger. The STi even goes one step further and has a water spray that shoots water onto the intercooler vanes to add EVEN MORE cooling effect (through evaporation) to the intake charge. People who want EXTREME performance put dry ice in a container on top of the intercooler to get the MAX density of intake charge possible!!!

A supercharger does the same thing, but instead of being driven by the exhaust stream, it's driven from a belt off the crank shaft. The advantage of that is that there is no lag between pushing on the throttle and the boost taking place, you don't have to wait for the exhaust gasses to spool up the compressor, it's instantaneous. The down side is that a supercharger uses some of the engine power to drive it.

Sorry about being so long winded on my first post, but I thought some clarifiaction might be appreciated...

Hoku,The only thing I might add to this excellent discussion is how a turbocharger works just in case you don't know...There are two halves to a turbocharger, one side is in the hot exhaust stream, exiting the engine, which causes the turbine impeller blades to spin a shaft. The shaft goes through a bearing (cooled by engine oil, or water) and into another chamber where another turbine (connected to the same shaft) compresses the air that comes into the engine through the air cleaner. This forces more air into the combustion chamber than could normally be drawn in by the piston, which creates a vacuum (sucking fuel/air in) as it goes down in the cylinder. Some of the heat from the exhaust impeller is conducted through the shaft to the compressor, and consequently heats the intake air charge. The intercooler is between the turbocharger compressor, and as was said earlier, it cools the intake charge before it goes into the cylinder so you get even more fuel/air mixture than could normally be compressed by the turbocharger. The STi even goes one step further and has a water spray that shoots water onto the intercooler vanes to add EVEN MORE cooling effect (through evaporation) to the intake charge. People who want EXTREME performance put dry ice in a container on top of the intercooler to get the MAX density of intake charge possible!!!A supercharger does the same thing, but instead of being driven by the exhaust stream, it's driven from a belt off the crank shaft. The advantage of that is that there is no lag between pushing on the throttle and the boost taking place, you don't have to wait for the exhaust gasses to spool up the compressor, it's instantaneous. The down side is that a supercharger uses some of the engine power to drive it.Sorry about being so long winded on my first post, but I thought some clarifiaction might be appreciated...