nick y

iTrader: (1)

which is better for overall performance and why?

for the street?

for the track?

lookin to put together 700 to 750 rwhp 03 c5.

any feedback will be appreciated

granitemonkey

Well, i think air to water is the best for drag racing. You can fill the tank with ice water and run a very cold boost charge. Just my .02


Brandon

andy98Z

iTrader: (4)

AIR to Water-
If you burn your finger what cools it down faster waving it around in the air or running it under water?
What about a hot pan off the stove? Letting it sit or running water over it to cool it down?

AIR to water is more efficient...especially when packed with ice water, however after along period of driving the water may heat up and not be more efficent then air to air.

Trvln Nalzmn

The downside to air/water is its far more complicated than air/air. You need a pump to pump the water and you have to cool the water which normally means that a radiator is needed. I'd say that water/air is heavier too.

Pro Stock John

iTrader: (34)

I suggest air to air.

Air to water is messy, and more complicated. Plus to really see a benefit from it you need a bigger (water) tank than what most folks are using.

I helped prototype a Griffin FMIC (air air) that is pretty popular right now.

My inlet air temps only go up 20F on a dyno pull.

jRaskell

iTrader: (1)

Air to water is ONLY more efficient if you're starting off with cold water. For drag racing it is certainly ideal.

For any sort of long duration racing and for street driving, air to air is more efficient because you aren't going to keep that water iced for long periods of time (unless you've got several pounds of ice stored somewhere in the car on reserve). The inefficiencies come from the heat transfer between the two mediums. In air to water, you have two transfers occuring. The first is transfering the heat from the intake charge into the water, and the second is transfering the heat from the water into ambient air. So you're losing efficiency across two mediums. With air to air, you have only the efficiency of transfering the heat from the intake charge directly into ambient air.

As long as you can keep your water supply well below ambient temps, air to water is more efficient. If not, water temps WILL rise and remain above ambient temps, and your overall efficiency will be less than an air to air setup.

The one other advantage air to water has is compactness of the system. Where you do see it used outside of drag racing, you will find it is a result of space limitations. You can get away with using smaller cores for both transfers because water conducts heat well and has a fairly high thermal capacity. Air itself doesn't conduct heat very well at all, so for the air to air intercoolers to work well, you need a LOT of surface area to transfer the heat from the intake charge into the intercooler metal, and then from the intercooler metal into the ambient air.

In the end though, the outcome is going to be far more dependant on the implementation. A well designed air to water system will be far better than a poorly designed air to air system. And a well designed air to air system may require a lot of work integrating it into the limited space our f-bodies have available.

MIGHTYMOUSE

iTrader: (59)

street or track, liquid is more effective at keeping IAT's down. if its worth the weight,cost and complication, thats up to you. mine is liquid.

Pro Stock John

iTrader: (34)

Well based on what I saw with a friend's car, a 5 gallon tank was not adequate the ice was boiilng at the end of a pass. This was when the car was making 147-150mph passes. He is trying air/air this year.

JZ 97 SS 1500

iTrader: (2)

Strange after several 1000+rwhp dyno pulls on a stang, a 5 gallon cell of water was still real cold and ice was only used, and IAT's were only 85 to 90 degs...hehe.

Jose

Guido

I have to agree with Jose. I even had a 3 gallon cell in my car, and it lasted through a few pulls. It was still cool. Even after my 10.95 pass, there were still chunks of ice floating around in the tank.

Remember, 3 gallon cell only.

5 gallon seems pretty standard.

John, i fail to see how your friend switching from a water/air cooler to air/air is going to get his IAT's DOWN. Perhaps he had something else flubbed up. Inefficient water/air core?

S_J_H

I'm pretty happy with the air to water system I built from scratch.
I have a 6 gal tank in the rear and converted the big ac condenser for radiator duty. Not sure what would happen after a couple hours of operation as I rarely drive it for that long, but a 40-60 minute cruise and the water is only a couple degrees above ambient.

Steve

InvisibleSun

Just curious, Steve, but after a 40-60 min drive do you have to refill the water at all? How often do you have to add water to it? Thanks!

S_J_H

it's a closed loop system and doesn't need to be refilled unless you want to refill with ice water or cold water at the track.. Only way water will be lost is by evaporation through the vent line.
And that's going to take a few years most likely.
But the larger the tank the more stable the water temp will be for a longer period of time.

Got Me SOM

iTrader: (2)

air to water, if you look at the really fast guys that run (8 seconds or faster) most if not all use AIR TO WATER setups.

slow

iTrader: (7)

and how many of them use a front mounted air/water heat exchanger. and how many have a usable passenger seat?

most of the cars like that, have a large icbox on the passenger seat area, and run ice

Ryan

Z8'S

iTrader: (6)

I ran a Spearco air/water in my car and used 20lbs of ice in a 5 gal. cell. We started the pass at 62* by the time we were going thru the lights the IAT' s were at 197*and upon returning to the pits the water was boiling! This was an intercooler that is suppose to flow 1500cfm. At 3.5 seconds into the run it was already at 150*IAT'S. This year I have switched to a Griffen air/air and saved approx. 62lbs and am praying that I will see some decent IAT numbers. Only time will tell.

Trvln Nalzmn

I calculate that you need well over 1000hp to boil 5 gallons of water in 10 secs. Thats power to heat JUST the water.

Thats water (not ice) at 0 C to 100 C.

Cmarsh93z

Id have to agree with others, and say something is not right with that setup. I wonder if you had some sort of core blockage? What kind of pump where you using? We used a twocore Air/water with 5 gallons on a D1X car awhile back, and with ice water...IAT's where 62 degrees at the end of a run. The Ice would melt, but it would still be cold water. Going from 62 -> 150 degrees in 3 secs just seems odd with ice. I can't imagine the IAT's needed to melt that much ice that quick!


Chris

Crunch

One other benefit to air to water:
The water (or antifreeze) is being pumped through the system by the water pump and is cooling the system down even when the car is sitting still.
Air-to-air only works while the car is moving - air has to blow very quickly across the intake assembly for it to stay cool.

buschman

Air to air is far better on the street. Ambient air temps aren't effected by engine temps. It's a constant. But as has been said icing the air to water intercoolers down at the track is a real advantage. But only an advantage if ice is used. Not a realistic option for the street or road racing. So you just have to ask yourself which arena is more important to you.

Mike