Hot air in stainless steel I/C piping

[TSiRocker]

Hi,

I am a noob here, so please excuse my dumb question.

I am running stainless steel i/c piping and wondering during summer the hot compressed air travelling into the intake manifold would lead to early combustion because of the hot air inside the combustion chamber thus leading to more Knock?

 

[Thomas91169]

thats what an intercooler is for. it cools down the air after the turbo. its like a radiator for cooling down the air coming into the engine.

 

[HokieDSM]

The air that's going through your IC pipes will always be pretty warm - the Intercooler helps, but it's still gonna be a fair bit hotter than outside temperatures after it passes through the compressor housing of the turbo - that is directly linked to the turbine side, which is processing gasses that are usually well in excess of 900*F.

 

[psychlow]

Compressor blades spinning at over 100,000 RPM tend to heat air quite a bit.

If you're getting knock due to it, invest in a water injection system or a better intercooler.

 

[psychlow]

Also, I'd thought I'd mention that the heat isn't a product of the steel I/C piping - it was there with the stock rubber piping, but it wasn't as noticeable since the rubber insulated much of the heat and wouldn't let it transfer to the surface.

Thus, you're actually getting mildly cooler air to the motor with steel pipes vs. rubber.

 

[Defiant]

Compressor blades spinning at over 100,000 RPM tend to heat air quite a bit.

It's from the compression, not the speed. You can get air just as hot with a bicycle pump if you put enough pressure on it.
Air coming out of a T-25 at moderate-chat will be over 225°F.

Hotter air will increase knock, but stainless IC tubing won't significantly increase the heat. Which is why you don't see the IC piping being insulated.

 

[psychlow]

It's from the compression, not the speed.

True, but it depends on the situation. If you're out of the efficiency range of a turbo (say 17PSI on a T25), the added speed that the compressor blades spin will heat the air more than a larger turbo at the same pressure. You'll get less air with the same volume - the air will be less dense.

Which is part of the reason that you can boost 10PSI and get 300WHP on a 60-1 trim, and boost 10PSI on a T25 and get 160WHP.