I’ve been researching Air-Water Intercooling for my car for a variety of reasons…thieves…cops…and just something different than typical turbo kit.
OT:
Here’s a great parts site for the DIYer http://www.frozenboost.com/
They have pretty much anything you’d need, although I’ve found better pricing on Ebay for some of the components. Junkyards should produce some nice cost effective alternatives as well.
/OT
Here are some observations from my research, feel free to chime in if I’m wrong or forgot something.
Legend:
A-W: Air to Water
A-A: Air to Air
I/C: Intercooler
A-A Parts List:
-Air to Air Intercooler
-Couplers
-A fair amount of intercooler piping
-Mounting brackets/tabs
-Hose clamps (or zip ties if u feel ghetto)
A-W Parts List:
-Air-Water Intercooler
-Electric Water pump
-Heat Exchanger (Fan optional, but recommended. They are cheap anyway.)
-Fluid Reservoir (Optional. Lots of drag cars have these so that they can pack it with ice and get crazy low intake temps. Most come with screens to prevent ice cubes clogging the pump. Not really practical for a daily driver, but if it’s a toy car, you can get decent driving time with a bag or two of ice.)
-Couplers
-Fair length of hi-temp hose
-Mounting brackets/tabs
-Hose clamps (or zip ties if u feel ghetto)
-Slightly less IC piping vs. an A-A setup.
Note: Both A-A and A-W setups should be properly sized to the turbo, as using too small of an IC or using a turbo outside of its efficiency range will produce excessive hot air. Be smart, think & plan ahead.
Air to Water PROs:
-
Less pressure loss across the I/C. On average, approx 0.1 psi of pressure loss. Some sites claim as little as 0.05 psi pressure drop which is pretty wild. A-A have pressure losses of approx 1.0 psi…that’s 10-20x or more pressure loss.
-
A-W has more consistent charge temps vs. A-A, which suffers from I/C heat soak. A-A ICs depend on forward motion to cool, so if you’re sitting still, that IC gets hot. Ambient temps can also cause variation of air temps (hot summer day).
A well designed A-W system should incorporate a fan on the heat exchanger, which provides consistency since it will still cool when the car is standing still. There will be less of a temperature spike to overcome vs. an A-A which has heatsoaked and will take a few seconds for its temp to drop back down as the car begins moving again.
An alternative here would be to slap on a fan or two on the A-A IC and/or incorporate water mister/sprayers commonly found in Evos and STIs.
-
“Water” absorbs/releases more heat than just plain air by itself. Think of Air cooled motors vs. water cooled motors as well as the water sprayers on Evos and STIs mentioned above.
-
Less charge piping = quicker spool time & throttle response.
-
More freedom to mount the heat exchanger, since it doesn’t HAVE to be in the front of the car, or provided with ducting (like those MR2 intercooler ducts/scoops). This also helps maintain the cooling efficiency of the radiator and AC compressor if you have AC since a big ass front mount isn’t blocking the rad & AC comp. I’d say this is more of a benefit to MR cars vs. FF or FR cars.
-
You can be :snky: “Nah yo, my hood latch is broken son, but you don’t see a front mount right? This shit aint turbo…”
Air to Water CONs:
- More components that can break. Actually the only two things you really need to keep an eye on is the electric water pump, which range from 40-125 bucks or so to replace, and the heat exchanger fan if you are running one (you should!). The other components are your A-W IC lines, fittings, and heat exchanger which have no moving parts so the only thing I can see failing with these are if they are shitty quality and you crack a weld or spring a leak in the exchanger.
If you invest in an OEM style pump, such as the http://www.frozenboost.com/product_info.php?cPath=212&products_id=1001&osCsid=44105a3b6ac662241ad8286641503d0a, you should be good to go for a good WHILE. Some kits use http://www.frozenboost.com/product_info.php?cPath=212&products_id=1000&osCsid=44105a3b6ac662241ad8286641503d0ap, but I don’t trust them with hot water…they are like half the price though. Your call here. I’d rather have the peace of mind.
-
Possible freezing of the “Water” if you live in cold climates, like good ol Tuffalo. Soultion: use 50/50 water/anti-freeze just like in your radiator.
-
Possible corrosion of the internals of the system. Solution: use distilled water.
-
CAN’T BE :snky: - Cops & Thieves will notice that shiny, blinging front mount all day. Of course, you can always paint it black, but hardly anyone does that since they won’t be able to garner suckage “OMGawd is that TERRBOWWWWWW??? omggggg”
-
COST - I only put this as a con because you can pick up USED air-air I/Cs or el-cheapo made in China A-A I/Cs for pretty cheap these days.
If you really break it down though, you end up spending about 250-400 for an A-W setup. New A-A intercoolers alone will run about that much, so there’s not really much of a price differential.
Conclusion:
A-W FTW. Happy :snky: boosting.
Chemistry side note:
Try not to use straight up (distilled) water in your A-W setup, or even in your radiator. Using a 50/50 mix of water/anti-freeze will help increase cooling efficiency.
Water by itself, while better than air, isn’t all THAT great with heat. Some people also put a drop or two of dish soap to reduce water tension as a free “booster.” The concept behind it is basically to help water conduct heat more efficiently. Don’t put in too much otherwise you’ll have an ass load of foaming)
Rather than me plagiarize, go here for the details, charts, graphs, and visuals:
