Chevrolet Cruze Forums banner
1 - 6 of 6 Posts

·
Registered
Joined
·
1,304 Posts
Discussion Starter · #1 ·
Gentlemen, what exactly is the purpose of the intercooler? Is it to help reduce the temperature of the air/fuel before entering the combustion chamber? I see we can use lower octane in the cooler weather. Is this the reason why?
 

·
Premium Member
Joined
·
6,917 Posts
That is exactly the purpose of the intercooler. Turbos can get extremely hot so without an intercooler the air entering the engine would always be 140F outside temp hot. Dealing with that heat without the intercooler would require them to pull more timing and lower boost, so it would make having the turbo less beneficial.

I guess the best example of this is have you ever experienced heat soak driving in traffic in 80F+ summer weather? That's what the engine would feel like in a much wider range of conditions.
 

·
Registered
Joined
·
625 Posts
Like what spacedout said turbos do get hot. Your getting air from whats bolted to your exhaust manifold and as we all know (have the scars to prove it) exhaust is hot lol. The intercooler is used inbetween the turbo and throttle to do just that, cool the air. The lower the air temp the better power you will have. You can search on here alone to see about what people have replaced their factory for a front mount and have lowered iat's a few degrees. No to mention they look cool ;)
 

·
Administrator, Resident Tater Salad
Joined
·
17,486 Posts
Well, sort of. Compressing the air to a higher PSI is what really heats up the air - the heat from the exhaust side of the turbo minimally so in comparison.

The annoying thing about these intercoolers, and most "non-sport" turbo cars, is that the intercooler is sandwiched between the AC condensor (HOT in the summer) and radiator (also hot in the summer). Without air flow over the sammich, your intake air temps can be quite hot until you get rolling again, and the Cruze will fall on its face at times trying to keep knock from damaging the engine.
 

·
Conservative Acoustic Foam
Joined
·
1,028 Posts
Ron white beat me to it. It's not so much that the compressor of the turbo is hot from the EGT (exhaust gas temps), it's a matter of simple physics that compression causes heat.

In addition to the point about hot air being more prone to pre-ignition ("knocking"), since hot air is less dense that cool air it loses a lot of efficiency. So we cool it back down a bit through the intercooler so that more air can be packed into the combustion chamber during the intake stroke. More air (because it is more dense by being cooled off) means more efficiency ("power").
 

·
Registered
Joined
·
1,304 Posts
Discussion Starter · #6 ·
Well, sort of. Compressing the air to a higher PSI is what really heats up the air - the heat from the exhaust side of the turbo minimally so in comparison.

The annoying thing about these intercoolers, and most "non-sport" turbo cars, is that the intercooler is sandwiched between the AC condensor (HOT in the summer) and radiator (also hot in the summer). Without air flow over the sammich, your intake air temps can be quite hot until you get rolling again, and the Cruze will fall on its face at times trying to keep knock from damaging the engine.
Sounds like a poor design but with all the crap stuffed under the hood these days I suppose there's no where else to put it.
Speaking of knock/dieseling, since I rebuilt my chevelle I now leave it in gear after parking to shut it off to prevent dieseling and that's with 93.
 
1 - 6 of 6 Posts
Top