8kGoodENuff

So I was just thinking... I've been keeping a close eye on the Kraftwerks Kit and the Vortech Kit and I've noticed that their method of cooling the compressed air is different.

You have the KW kit that uses air-to-air cooling and then you have the VT kit that uses water (coolant)-to-air cooling. Now I know that water can absorb more heat than air could but the thing to remember here is that the water is operating at a much higher temperature than the air used in the air-to-air. On the flip side though, even though air doesn't absorb heat as efficiently as water, it does have a much lower operating temperature (dependent on the season of the year) and it does flow at a much higher rate.

So which is more effective at cooling?

Andre

blackey

Air to Air is more efficient by far. The water is still cooled by air in a Water to Air system.

Soul Coughing

i think the vortech and comptech setups were made the way they were because of packaging and charge drop.

2big4aS2000

depends on use of car
in a drag car, air-water would be better, as the longer the car was run the temps of the water would increase. for a daily driver the stock setup for the comptec or vortech air-water over a air to air the air to air would be better - but you could have boost lose due to piping and the intercooler, but with upgraded pump and radiator for the air to water i have seen 20+ degree drop on intake temps over original setups.

8kGoodENuff

By that... do you mean pressure drop?

I'm not sure of the specs of the centrifugal blower, but I'm pretty sure it would be able to run through an air-to-air intercooler without much of a pressure drop compared to any other charger.

The packaging though I think is the main concern for CT & VT.

I know Mercedes Benz is smart and they use refrigerant to cool off the compressed air... now that's bada$$.

Andre

MugenRioS2k

I would disagree

In the end it madders what the approach of the system is after steady state conditions have been met and are constant.


In a properly designed A2W system the front heat exchanger has more heat rejection capacity then the heat absorption of the core.
This ensures that the capacity of the

dsddcd

[QUOTE=MugenRioS2k,Nov 12 2008, 02:14 PM] I would disagree

In the end it madders what the approach of the system is after steady state conditions have been met and are constant.


In a properly designed A2W system the front heat exchanger has more heat rejection capacity then the heat absorption of the core.
This ensures that the capacity of the

8kGoodENuff

That is true that A2A would have a less chance of components failing, which is always a plus, especially when at the track, but A2W I would think has a much better cooling capacity, of course depending on surface area and flow rate of the water.

Andre

snakeeater

I believe the biggest reason to use an air/water heat exchanger is because you can place the A2W exchanger anywhere you want. This allows you to keep the charge pipe routing as short as possible from compressor to throttle body. Theoretically, the shortest path should minimize lag time from off-boost into boost region. Maybe slightly better throttle response. Of course its also easier to package this way. The W2A exchanger mounted in front of radiator only needs soft 5/8" water lines run to it instead of hard 2.5" piping. I think it's a matter of convenience for installing more than anything else.

blackey

Seems like a lot of people here are guessing and are stating what they think, but really have no evidence or engineering behind it? If you think the a2w system is better show me how much air is needed to cool the water using math please.

I have tested both on a racetrack. The stock Vortech aftercooler vs the Ultimate Racing Intercooler. The Vortech system heatsoaked on the first lap and ran consistant temps of ambient + 90F. (Not good)

The Ultimate Racing intercooler was ambient + 3F. It was actually running cooler than the underhood temps where I was pulling air from.

If you calculate the energy it takes to pull heat out of water using air, it is staggering. The water is very efficient at pulling heat out of the air. Basically to pull the heat out of the water you reverse the process. Which inverts the equation. For drag racing the air to water is perfect. You can cool the air to less than ambient using dry ice. If you've ever seen how much ice it can use up you would be alarmed.

For street driving, most of the time the air to water is ok. For a canyon road drive the Air to Air will be better. For tracking, the air to air is definitely better.

Now it sounds to me the SOT kit has used a very high quality a2w system and a huge extra radiator to combat the problem. I've talked to Mark and they have the temps under control. The Vortech and Comptech kits, not so much.

A2W can be made to work, but is more complex and is more difficult to get right. There are more parts to fail, and those failures can be costly. The pluses are very little pressure drop, and you can mount the radiator anywhere, although I have yet to see anyone mount it any other place than in front of the radiator in the s2k.

The downside of air to air is the pressure drop. Figure a well designed A2A will have about 1psi more pressure drop than the A2W system. Not a problem with turbos, but something to consider with superchargers that are already at their RPM limit.