Intercooler Contribution
 

Just wondering what contribution the intercooler makes, in terms of more power/torque then without one.

ie on a 300 bhp (at the flywheel) scooby, at say 100 mph at 25º Celcius air temp.

Hope that's enough info......

An IC helps retain power, not adds power.

Generally, if that 100 mph was at cruise, then the IC would just be rmeoving heat soak and a little of the heat from compression. The charge temp out of the IC will be at or just above your air temp on a well designed IC and duct arrangement.

At peak boost, the turbo outlet temp may up to IRO 130 deg C. The IC now has to drop the charge temp by 130-25 dec C in order to avoid any power loss.
So the extra info needed is your air flow and charge temp at 100 mph to give a good estimate of power loss.

This website gives a good idea of the IC is doing:
Stealth 316 - Turbo Outlet Temperature

Nick

WIthout the IC you simply couldn't have a 300bhp Scooby. There's no way an ECU could run enough boost to make 300bhp out of 2 litres without an intercooled turbo system or an incredible engine build revving to 15000 rpm. You could perhaps run a very light pressure turbo which would hardly be worth having, and be looking at the kind of power figures a 2.0 Sport makes, normally aspirated. But a turbo by its very nature as a compressor, puts a hell of a lot of heat into the inlet charge. Even the most weedy IC can dump a hell of a lot of heat quickly. If you ever get hold of one, stick a hot hairdryer in one side and feel the stone cold air come out the other. This effect won't last long of course with a small IC, but it's better than blasting 100-200C charge air into the combustion chamber and then expecting to make any kind of repeatable power.