Cold air intakes

[Aussie Willy]

The particles don't change size, just the space between the particles does.

Cooler air, is more dense, it has more particles per unit volume, compared to warmer air.

Thanks mikey

 

[salute the ute]

Like people said above, VCM all the way.

 

[yxyx64]

just to clarify (no worries immortality - just doin my bit)

the air 'particles' DO change size. they expand at the molecular level as they gain energy from the temperature increase.

Simply put the little zoomy bits go faster so as they zoom around they are now going too fast to turn tight corners so they do a bigger zoomy path and take up more space. This particle size getting bigger is the exact reason that the fluid spreads apart, cause the 'particle' (that is expanding) then wants to get away from its neighbour (also expanding) that is now getting too close.

 

[SV6GUY]

just to clarify (no worries immortality - just doin my bit)

the air 'particles' DO change size. they expand at the molecular level as they gain energy from the temperature increase.

Simply put the little zoomy bits go faster so as they zoom around they are now going too fast to turn tight corners so they do a bigger zoomy path and take up more space. This particle size getting bigger is the exact reason that the fluid spreads apart, cause the 'particle' (that is expanding) then wants to get away from its neighbour (also expanding) that is now getting too close.

'particles' DO NOT expand, i can assure you as a chemistry graduate. But you're kinda on the right track, as air cools atoms that make up air move slower and can therefor pack more closely together which results in dense; oxygen rich, air.

As opposed to hot air which will have faster moving molecules which will not allow them to pack as closely together resulting in less dense air.

A good analogy to this would be traffic, as traffic slows you get more cars in a given area as opposed to fast moving traffic which will have less cars in a given area.

 

[yxyx64]

correct; particles such as electrons, neutrinos, photons etc do not expand with a change in quanta (except at light speed).

notice how the word particle was written as 'particle'. Indeed, written specifically as air 'particle'. this was specifically done so as new terminology such as neutrinos and photons or proton or whatever were not introduced to the reader of a car forum trying to understand the basics of this hot air business. readers here would understand an air particle as being a little chunk of air - not electrons surrounding protons and neutrons etc....

to these people they have now been left again without a basic understanding of what happens when air heats up. this understanding was what they needed. what they did not need was a partial definition of a particle.

sorry forum i have failed you by not including bohrs modelling in my previous explanation of density.

or to put it scientifically...when you are driving down the highway with your throttle plate MORE than 80% closed your cold air anything will make less difference than leaving ur fat ass wife at home and driving alone will.

apologies to all fat arse wives

 

[greenacc]

As another science graduate this thread makes me LOL ! I think what you guys are talking about is molecular vibrations ? The amplitude of vibration increased as the substance heats up so in effect those molecules occupy a larger volume of space. Anyway cold air makes you go more faster :beer chug:
I'd love to know the real temperature difference between the best CAI and a standard intake. What are we talking, 2 or 3 degrees at most ?

 

[WogBoyz]

As another science graduate this thread makes me LOL ! I think what you guys are talking about is molecular vibrations ? The amplitude of vibration increased as the substance heats up so in effect those molecules occupy a larger volume of space. Anyway cold air makes you go more faster :beer chug:
I'd love to know the real temperature difference between the best CAI and a standard intake. What are we talking, 2 or 3 degrees at most ?

dunno man my standard intake got pretty hot alot of heat soak, wheres as the vcm seems to be much cooler

 

[yxyx64]

'pretty hot eh'......see, there are some words that I can fully get the meaning of....

whereas if Wogboyz and I were to more correctly discuss Fouriers Law and how it relates to the temperature gradients of the material concerned (the law being used in its integral form of course) as part of the determination of thermal conductivity, then we sort of lose people on a car forum.

It is all about context.

Thankyou Wogboyz. (unless you meant 'pretty hot' as in 'I would like to shag you' in which case I will put you down for the Zoo trip)

 

[yxyx64]

so back to the hot air thing,

think of air as being golf balls. When your piston goes down you fill up the cylinder with as many golf balls (chunks of air we will call air particles to annoy the geeks) as you can. The more golf balls then the more fuel can be burnt (more POWA)

but when the air is hot the golf balls expand to the size of tennis balls. So less can fit in our cylinders. So less fuel can be put in to burn. so LESS powa.

that is correct men, the little air particles expand when they get hot so not as many can fit into the same size hole in ur engine (again phrased just to annoy the geeks).

for the geeks: if my exhaust is round and covered in sooty stuff does that make it a black hole?

 

[Aussie Willy]

Ok, so I had this can of worms and well.............................