Kooldino said:
I don't know about cars, but in the computer world, water cooling is much more efficient than air.
I think the point here is that although water has the potential to be a more effective cooling agent, because of its high heat capacity, it is difficult to employ effectively in a car. Obviously car engines don't use air cooling anymore because air connot transfer heat nearly as quick. But on a turbo sysytem, the potential gains to be had by water cooling are not worth the added complexity.
Take for example the GMC Syclone\Typhoon, a turboengine with w/a intercooler. First of all the water can only be as cold as the surrounding air (unless you chill w/ ice, but who does this just driving around?) When the truck first runs, intake temps are lower than an a/a int., bc the water transfers heat more effectively, even though the cooling mediums (air vs water) are the same. However this situation quickly changes as the car runs for two reasons. One (as already stated) the water warms up from the heat from the intake charge. Second, the water res is located under the hood, so soaks up heat from the engine. The water cannot cool the intake charge to less than the water temp So if the water heats to 120F, but the outside temp is 70F, the a/a int would be more effective at this point, for example. (The exact crossover point in efficiency would depend, on your setup. A w/a int at 80F maybe more eff. than an a/a at 70F abient temp, but then decreaingly eff as water heats.)
To employ an w/a in you would need a reservoir, water pump, lines, intercooler, and potentially a radiator to cool water, and prob a bunch of other stuff. Where do you mount the res? Underhood is easy, but gets hotter. Could put in trunk, but is more complex, and you take up space. Plus your adding extra weight and parts that need to be maintained and could potentially fail.
While an a/a just sits there. No worries.
PS. GMC went this route b/c there was nowhere to mount an a/a that would be suitable for a factory setup. The Sy/Ty's were built off of S10 platforms that where never designed to house int, or even such powerful engines. Mounting in front of the rad. disrupted an already overburdened cooling sys. It was not out of pref, but out of practicallity.
I am curious of pressure drops over an a/a vs a w/a int tho...?