Another dull question from the QorbeQ stable ...

I was recently reading about the water misting option for the intercooler and one thing struck me about having nice cold intake air ... I have a built-in system for reducing air temperature (namely, the aircon) ... which could provide cooler, denser, air to the inlet (somehow - lord knows how) couldn't it?

Or couldn't it?

air con drains power from the engine to run it,robbing peter to pay paul i think the sayiing is

After you posted that I thought ... "hrrm that makes total sense I must be talking rubbish".

But then I thought some more about it. Take a typical portable home air-conditioning system, for example. It must remove more energy from the room than it uses to power itself, otherwise the room would heat up more. The same must apply to the "normal" cooling mechanism in a car - the pumped water system. It must use less energy (and thus generate less heat) to run the cooling system than the system removes from the engine, otherwise there's no point in it.

Granted, providing cooler, denser air to the intake isn't really comparable to chilling the hot bits directly, but it still does make me wonder.

For example, I can tell (via the delights of the ass-dyno) that the car pulls harder on colder days when the air is denser, but I'll be buggered if I can tell the difference between accelerating with the air con on and with it off ...

I wonder if the air con can provide enough cold air to make a difference in power ... hrrm ... where do those pipes go again ... ?

but I'll be buggered if I can tell the difference between accelerating with the air con on and with it off ...

Try driving at a constant 120mph on ECON and then fiddle below to hit the A/C button... You'll notice.

only do this on a private road, etc, etc

Another dull question from the QorbeQ stable ...

I was recently reading about the water misting option for the intercooler and one thing struck me about having nice cold intake air ... I have a built-in system for reducing air temperature (namely' date=' the aircon) ... which could provide cooler, denser, air to the inlet (somehow - lord knows how) couldn't it?

Or couldn't it?[/quote']

It's a nice idea, but the laws of thermodynamics tend to get in your way...

The aircon cools and dries the air going into the cabin, but in doing so it needs to extract 512 calories for every gram of water vapour in the air. This takes power from the engine.

On the other hand, an IC mister works by evaporating water from the surface of the intercooler, making (slightly) warmer moist air which then disperses into the surrounding atmosphere. If you could get a gram of water to evaporate off the intercooler every second, it would be equivalent to running the engine air intake through a 2.2 kW (approx 3HP) refrigerator - but without any cost!

Doesn't Ford intend to give the next Fast version of the Mustang a system that give it 30 secs of cool damp air for maxuim take off power?

Cheers

Mike

But then I thought some more about it. Take a typical portable home air-conditioning system, for example. It must remove more energy from the room than it uses to power itself, otherwise the room would heat up more.

No, don't think so, air might feel cool near the machine, but the net result would be that the room gets warmer. As far as I know, no man made invention is anywhere near 100% efficient. For example if you take a fridge in a sealed room and leave it on with the door open, the room will get hotter, not colder. Proper air con units have the heat exchanger mounted outside the building to dissipate air to the atmosphere..... That enough physics for one day though.

Proper air con units have the heat exchanger mounted outside the building to dissipate air to the atmosphere..... That enough physics for one day though.

Indeed - I meant the kind that you dangle the heat exchanger outside - which is exactly what the air-con does isn't it?

Anyhoo, the maths that Mike spouted sound good enough to stop any thoughts of air-con rerouting I may have had in mind

tis true about the mustang thingy, they have made a system which uses the aircon to cool a bucket load of air to something stupid like -60 then when you are on full throttle and want a hit of power you can dump the cold air into the intake, apparently with about the same power gains as a 50 shot of nos, but toally safe, infact safer as its nice cold air. only takes a couple minutes to re-charge aswell