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Originally Posted by aussieboxy
15,500 Euro seems like a lot of money. Seems like you could spend you money more effectively either doing other things.
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Par-tay!
Air-water ICs are good for packaging but have some limitations for a street/road race engine. Each heat exchanger in a system is at best about 75% efficient (i.e., it can remove about 75% of the temperature difference between the internal flow and the external ambient temp). For example, if the outside temperature is 80f flowing across the intercooler, and the charge inside the IC comes in at 180f, a 75% efficiency would produce a temp drop of (180-80)*75 = 75 degrees, so outlet temp would be 180-75 = 105f.
Now when you stack heat exchangers, as you must in a air-water system (there's an air-water exchanger in the front of the car to cool the water, then a water-air exchanger on the engine to cool the compressed air) the efficiencies multiply, so 0.75*0.75 = 56% system efficiency. (And this is a contrived "best case" example, 75% is rarely attainable in the real world.)
On the other hand, an air-water exchanger can be used with a cool-tank to get the water well below ambient temp (just toss a block of dry ice in the tank) and for short duration events like drag racing this can be a very significant advantage. (You can do the same sort of thing with an air-air cooler by spraying nitrous across it instead of just leaving it out in the air; the expansion of the nitrous from liquid phase to gaseous phase nets a huge temperature drop.)
The pump in Gary's car is the oil scavenger for the turbos. Turbochargers drain their cooling/lubricating oil out the bottom using gravity, there's no pump system inherent in the turbo to get rid of it. On most installs, the turbo is well above the oil pan, so the drain hose just drops back into the pan r the side of the block or whatever, but when packaging forces the turbo down low, you must suck the oil out of the turbo and pump it back into the engine. Here you see the turbo drain lines emptying into a little aluminum plemum, and the pump then evacuates the plenum back into the engine.
Eric