Keeping Intake cold and exhaust hot?
Keeping Intake cold and exhaust hot?
(OP)
I have heard of some racers using insulation materials on both on air intake and exhaust headers to improve peformance. By keeping intake air cooler - more air? And by keeping exhaust system hot - air exits more quickly? Can anyone here confirm this? Has anyone ever done dyno tests on systems which have insulated intake and exhuast systems? I'm thinking benefits can only be realized when car has warmed up and is hot?





RE: Keeping Intake cold and exhaust hot?
Keeping the exhaust hot will be useful only with an exhaust turbine, because the turbine power depends of the exhaust mass flow, pressure and temperature. Usually the exhaust turbine is coupled to a centrifugal compressor to form a turbocharger. Under high load and revs, the power of the turbine is in excess of the compressor requirement, especially with a gasoline engine, so that there's a waste gate which diverts a part of the exhaust gas to by-pass the turbine. But at low revs, the power of the turbine is insufficient to provide an adequate boost pressure, so any increase of the exhaust temperature will help.
Cheers
Aorangi
RE: Keeping Intake cold and exhaust hot?
Cheers
Greg Locock
RE: Keeping Intake cold and exhaust hot?
Dave
RE: Keeping Intake cold and exhaust hot?
The temperature of heat rejection, which I think is what you are referring to, needs to be as low as possible for maximum efficiency doesn't it? it would be the temperature at which expansion finishes, either way.
Cheers
Greg Locock
RE: Keeping Intake cold and exhaust hot?
by putting a turbine in the path of the exhaust gases and extracting the useful energy out of them, yes u can actually increse efficiency.
waqahmad
RE: Keeping Intake cold and exhaust hot?
RE: Keeping Intake cold and exhaust hot?
RE: Keeping Intake cold and exhaust hot?
RE: Keeping Intake cold and exhaust hot?
RE: Keeping Intake cold and exhaust hot?
For dyno testing...many companies who make manufacture and sell intakes, when they show the dyno plot of horsepower gains, they usually show the best run, the earlier runs, before heat from the engine compartment comes into play.
I remember Weapon-R trying to market a "short ram" intake at newcelica.org, claiming it's just as effective as an Injen CAI. They tested with the hood open (for obvious reasons) and they threw out the data due to heat soak (for obvious reasons).
RE: Keeping Intake cold and exhaust hot?
RE: Keeping Intake cold and exhaust hot?
Blacksmith
RE: Keeping Intake cold and exhaust hot?
One way to improve the heat problem with al intakes is the thermal isolator gaskets available for some of the more common engines. Real simple and real cheap, but should help by slowing down heat transfer from the cylinder head.
RE: Keeping Intake cold and exhaust hot?