Originally posted by lonezergling:
The important thing to remember is that the system, w2a or a2a will NEVER be able to cool to or below ambient temperature.

If you want my personal opinion, you already have a w2a, it's efficient, it's smaller, it can be placed easier, you can add an ice box to cool even closer to ambient temperature, and you won't lose any boost in the piping.

Stick with the W2A.

How can an air-to-air intercooler be more efficient than a water based intercooler?
There is an overwhelming quantity of ambient air available to cool an air-to-air core relative to the charge air thru the inside of the intercooler (The iced down water intercooler is the only exception to this argument.). At just 60 mph, with a 300 bhp engine at full tilt, the ambient air available to cool the intercooler is about ten times the amount of charge air needed to make the 300 hp. Whereas the water intercooler largely stores the heat in the water until off throttle allows a reverse exchange. Some heat is expelled from a front water cooler, but the temperature difference between the water and ambient air is not large enough to drive out much heat. Another way to view the situation is that ultimately the heat removed from the air charge must go into the atmosphere regardless of whether it's from an air intercooler or a water based intercooler. The problem with the water intercooler is that the heat has more barriers to cross to reach the atmosphere than the air intercooler. Like it or not, each barrier represents a resistance to the transfer of heat. The net result; more barriers, less heat transfer.


What are the relative merits of an air or water-cooled intercooler and which would suit my purposes best?
This depends on the circumstances. These circumstances are; street use, drag racing, or endurance racing (more than two minutes).

Street use: The air-to-air intercooler will prove superior in efficiency when sized properly.

Drag racing: The short spurt of power allows the iced water to cool the charge air to below ambient temperature.

Endurance racing: The air-to-air intercooler is clearly superior due to the shorter route of getting the heat out of the air charge and into the atmosphere. Endurance racing would preclude the use of ice water, thus negating the singular advantage of the water intercooler. Further, the air-to-air intercooler is (virtually, see comments below) maintenance free.

Water to air means incredibly low pressure drop.

Pressure drop on a standard water to air intercooler core is only .05 PSI.

Water to air means better throttle response.

Instead of the horrible mess of pipes that is normally associated with an air to air intercooler, a water to air intercooler can be mounted in the engine bay, directly between the turbo outlet and the throttle body. A shorter intake route with fewer bends is beneficial in every way.

Water to air means no heat soak.

A water to air intercooler setup circulates water through the core even when the car is not moving.

Bugatti Veyron.

The Bugatti Veyron is equipped with a water to air intercooler. 1,001 horsepower, 250 MPH cars might be somewhat common at the drag strip, but that's not what the Veyron is about. The Veyron is an all-around car, not just a top-speed monster. That's the reason it is the most expensive car in the world and they still lose money on every one. Bugatti chose a water to air intercooler for this car because it is absolutely the best system available. The Ford GT and Ariel Atom also use water to air, for a more real-world example.

Why does it work?

Water does a better job of drawing the heat out of metal than air. Look at engine cooling - how many air-cooled engines are there? Not many, because water does a much more effective job at cooling. So much more, in fact, that it is impossible to engineer a solution for a modern high performance engine that is air cooled.

Originally posted by lonezergling:
http://www.stattama.com/index.cfm?fuseaction=browse&id=52262&pageid=53


ZZP's car is W2A.

Every super-higher performance turbo build uses a W2A IC because when you are dealing with that kind of power, W2A is the most efficient cooler.

A2A is good for the streets because it's zero maintenance. Put it in and never worry about it again. Plus the look of a fat heat exchanger on the front of a car is a scary look.

If you want serious power, stick with the W2A. It's what the big boys use.

You've already got it, don't go messing up a good thing when the best is already in front of you.

Hoowever, is your W2A IC an M90 IC and you are getting the block-off plate?

If that's the case, you may want to buy ZZP's prototype W2A IC core for turbos and csc's

http://www.zzperformance.com/grand_prix/products1.php?id=714&catid=160

Or even the block-off plate IC. I wouldn't recommend using just an M90 IC core with the rotors pulled out.