Quote:
Originally Posted by E90Brad
I am not a fluid/aerodynamic engineer, I am also a crappy physicist... I even had to look up the spelling of physicist but I have something to add futher to what Shellacked has said.
There is a relationship between pressure, tempature and volume in thermodynamics (pv=nRT). Let's assume related rates (air into engine and air going into intake) are negligible.
Without scoops, air is being forced into an area of consistant volume (ie stock airbox) with an (assumably) relatively consistant temperature. If we assume that volume and ambient temp remain the same then we can use some logic to make an guess at what is actually happening when we add scoops.
Now we add scoops. If we assume that the scoops channel more air into the intake box (which I think is correct), then the increase in air should cause an increase in pressure (constant volume of airbox) which in turn will cause a decrease in intake temperature.
I would think that this effect would be greater with a stock airbox as the closed in area would allow air pressures within to increase. Those with upgraded intakes should see a lesser effect as the intake temperature would be manipulated by the engine temperature and there is usually no confined volume for pressurization to take place.
Now this is only one arguement. You could also argue (as someone has previously done) that the scoops get air from a (slightly) lower height and that contributes to lower air intake temps.
I am thinking of grabbing some Cyba scoops and looking at the difference in air intake temps and maybe even 0 - 100 times using a stock airbox and then a DCI.
Just my 0.02 on air scoops.
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If you compress air, it heats up, not the other way around.
As a matter of fact that's how diesels work. Remember the ideal gas law: p*V = n*R*T
All else being equal, if you increase pressure then temperature also goes up.
As I said in my last post a few months back, any negligible power increase will be offset by the increased weight of the equipment you need to install, as well as the increased drag coefficient you'll have.
You'll get better results by simply reducing weight: i.e. removing the toolkit from the trunk, losing 5 pounds of beer gut, or driving naked.