# Air-Water vs Air-Air Intercooling
**URL:** https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270
**Category:** NYSpeed Automotive
**Created:** [August 18, 2009, 3:02am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270 "2009-08-18T03:02:36Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Toda\_Party](https://forums.speedlife.net/u/Toda_Party)
#### Post date: [August 18, 2009, 3:02am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/1 "2009-08-18T03:02:36Z")
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/](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](http://SVT%20Cobra/Lightning%20%28Bosch%29%20pumps), 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](http://bilge%20pumps), 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:
[http://www.jcna.com/library/tech/tech0011.html](http://www.jcna.com/library/tech/tech0011.html)
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### Author:  [@97Ranger](https://forums.speedlife.net/u/97Ranger)
#### Post date: [August 18, 2009, 3:46am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/2 "2009-08-18T03:46:23Z")
may i ask why the cops would care if you have a front mount??
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### Author:  [@jay\_g](https://forums.speedlife.net/u/jay_g)
#### Post date: [August 18, 2009, 5:19am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/3 "2009-08-18T05:19:11Z")
I use the type 101 front mount-
[http://www.frozenboost.com/product\_info.php?cPath=217&products\_id=1026&osCsid=348d6ad06631446c1bd66bbb66b8a859](http://www.frozenboost.com/product_info.php?cPath=217&products_id=1026&osCsid=348d6ad06631446c1bd66bbb66b8a859)
Nice quality but it is heavy. Paired with a gm pump, cobra res, and a zzp core it keeps the heaten M90 300+degree outlet temps under control
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### Author:  [@Onyx\_Z32](https://forums.speedlife.net/u/Onyx_Z32)
#### Post date: [August 18, 2009, 5:41am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/4 "2009-08-18T05:41:35Z")
> [@97Ranger](#):
>
> may i ask why the cops would care if you have a front mount??
Some cops see front mounts and instantly think “street racer.” If you don’t want the attention from cops, or anyone for that matter, this might be the better way to go.
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### Author:  [@94excivic](https://forums.speedlife.net/u/94excivic)
#### Post date: [August 18, 2009, 5:56am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/5 "2009-08-18T05:56:54Z")
Devoistsi had this on his talon,and had great results with it…pretty cool setup
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### Author:  [@sureshot007](https://forums.speedlife.net/u/sureshot007)
#### Post date: [August 18, 2009, 6:06am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/6 "2009-08-18T06:06:56Z")
Just ask jose what happens when you spring a leak and it sucks water into your engine…
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### Author:  [@Jskrapper](https://forums.speedlife.net/u/Jskrapper)
#### Post date: [August 18, 2009, 6:52am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/7 "2009-08-18T06:52:31Z")
Black FMIC on a DD ftw.
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### Author:  [@38stang](https://forums.speedlife.net/u/38stang)
#### Post date: [August 18, 2009, 12:15pm UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/8 "2009-08-18T12:15:15Z")
Nice, read, A lot fo the Fox turbo mustangs in MOMs run Air to Water set ups, usually with the res tanks in the back of the car
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### Author:  [@BDR5oh](https://forums.speedlife.net/u/BDR5oh)
#### Post date: [August 18, 2009, 12:31pm UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/9 "2009-08-18T12:31:12Z")
The car at my house runs a A-W … no heat exchanger though … no need for it …
just run a mix of Ice/Water/alcohol(meth) …
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### Author:  [@tour](https://forums.speedlife.net/u/tour)
#### Post date: [August 18, 2009, 1:21pm UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/10 "2009-08-18T13:21:39Z")
they have some good prices on there
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### Author:  [@deliverator](https://forums.speedlife.net/u/deliverator)
#### Post date: [August 18, 2009, 1:41pm UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/11 "2009-08-18T13:41:42Z")
I think think the a/w cons are too troublesome vs. a black-painted a/a front-mount for most projects.
Heavy & more points of failure are the major issues.
Also, that list of pros implies that it doesn’t need forward motion to keep cooling - the heat’s got to go somewhere, and that’s the a/w’s heat exchanger. Which is cooled by -yep, you guessed it- air. It can last longer with minimal airflow before heat soaking due to the high specific heat of water, but that same thermal mass is also going to take longer to get back down to ambient after you start moving.
I had a Subaru Legacy awic, a Lightning f-150 pump, and a nice used mustang cobra heat exchanger all set to put on my last WRX, then decided to skip the weight, expense and hassle and just went with a beefier TMIC.
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### Author:  [@Toda\_Party](https://forums.speedlife.net/u/Toda_Party)
#### Post date: [August 18, 2009, 3:04pm UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/12 "2009-08-18T15:04:40Z")
> [@deliverator](#):
>
> I think think the a/w cons are too troublesome vs. a black-painted a/a front-mount for most projects.
>
> Heavy & more points of failure are the major issues.
Yeah for most run of the mill setups, A-A is simpler. Weight wise, unless its a race car is a marginal difference imo.
Points of failure like I mentioned are only the electric items, the pump and fan for the exchanger if you run one.
> [@deliverator](#):
>
> Also, that list of pros implies that it doesn’t need forward motion to keep cooling - the heat’s got to go somewhere, and that’s the a/w’s heat exchanger. Which is cooled by -yep, you guessed it- air. It can last longer with minimal airflow before heat soaking due to the high specific heat of water, but that same thermal mass is also going to take longer to get back down to ambient after you start moving.
If you aren’t moving forward, chances are u are not boosting anyway, my point was more about the heat soak.
The water is continually circulating, and yes the heat exchanger uses air to cool, but as I mentioned, if you’re looking for consistency you can’t beat the A-W.
> [@deliverator](#):
>
> I had a Subaru Legacy awic, a Lightning f-150 pump, and a nice used mustang cobra heat exchanger all set to put on my last WRX, then decided to skip the weight, expense and hassle and just went with a beefier TMIC.
You still have that stuff lol? WTB…
I’d think esp for a scoobarooo you’d want to go A-W since those top mounts are right on top of the motor and all, but with a thicker core and the water sprayers its prolly a negligible diff.
In the end, any IC is better than no IC…i’ve had my fun w/ A-A so i’m gonna fuck around w/ the A-W and see how I like it, chances are most people would never notice the differences I mentioned unless they are doing some datalogging.
That, and my car isn’t a factory boosted car, so a FMIC is a dead giveaway to steal it…two stolen cars will make u think a little differently I suppose.
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### Author:  [@Jskrapper](https://forums.speedlife.net/u/Jskrapper)
#### Post date: [August 18, 2009, 4:34pm UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/13 "2009-08-18T16:34:26Z")
> [@Toda Party](#):
>
> That, and my car isn’t a factory boosted car, so a FMIC is a dead giveaway to steal it…two stolen cars will make u think a little differently I suppose.
Good point especially considering your sig.
I have had about 10 people over the years ask why my custom radiator hoses were so big. It’s black so it must be a radiator.
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### Author:  [@clinzee](https://forums.speedlife.net/u/clinzee)
#### Post date: [August 18, 2009, 6:03pm UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/14 "2009-08-18T18:03:23Z")
I kind of skimmed through the whole thing and didn’t see heat soak as a problem with air-water. With the ion redline my dad had after a little bit of playing around it would get pretty heat soaked and drop in efficiency. A larger heat exchanger would have helped a lot but it can still be an issue.
In the three years I was on the forums for those cars I never once heard about water leaking into the engine. I have a black front mount on my car and never has anyone noticed it unless their face was in my bumper. I would go air to air just for the sake of simplicity.
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### Author:  [@breakstuff](https://forums.speedlife.net/u/breakstuff)
#### Post date: [November 9, 2010, 5:51am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/15 "2010-11-09T05:51:12Z")
I just started giving this some thought, good to hear a few positive reviews. If I can lose 6’ of 2.5" piping (fairly possible), the turbo would have to compress 348 cu. in. less air. Thats like losing twice the engine’s displacement in volume. I would think that should help throttle response, get rid of any lag, and make torque-steer an impossible battle lol
I don’t want to run too much glycol though because it takes away some of the water’s ability to transfer heat, but 50/50 is just enough to prevent a freeze up.
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### Author:  [@Haenszel](https://forums.speedlife.net/u/Haenszel)
#### Post date: [November 9, 2010, 6:36am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/16 "2010-11-09T06:36:26Z")
A nice big heat exchanger is key, with a fan on the back. It makes “re-cooling” after sitting in traffic a lot quicker. Having a big water reservoir is also great for cooling(more water to have to heat up) but it also means there’s more water to have to cool back down after sitting.
I love AW setups, but I personally would never put one on my car. I’m a simpleton.
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### Author:  [@Jack](https://forums.speedlife.net/u/Jack)
#### Post date: [November 9, 2010, 8:20am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/17 "2010-11-09T08:20:35Z")
My car is A-W and it works great. 😉
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### Author:  [@99\_civic\_si](https://forums.speedlife.net/u/99_civic_si)
#### Post date: [November 10, 2010, 12:15am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/18 "2010-11-10T00:15:46Z")
read the op and I gotta ask one thing…doesn’t water cool better than coolant? I was always under the impression that water cools better but obviously doesn’t have resistance to boiling or freezing and that’s where the coolant comes into play.
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### Author:  [@breakstuff](https://forums.speedlife.net/u/breakstuff)
#### Post date: [November 12, 2010, 9:40am UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/19 "2010-11-12T09:40:35Z")
Yes it does, but a 50/50 glycol water mix still has 85% of the heat capacity, if I’m reading this correctly.
[http://www.engineeringtoolbox.com/ethylene-glycol-d\_146.html](http://www.engineeringtoolbox.com/ethylene-glycol-d_146.html)
Also, I am going to try to do a pull style pump scheme. This way if there’s a leak in the intercooler, the pump will draw air through the hole rather than force water in 😉
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### Author:  [@turbo\_dreams](https://forums.speedlife.net/u/turbo_dreams)
#### Post date: [November 12, 2010, 5:02pm UTC](https://forums.speedlife.net/t/air-water-vs-air-air-intercooling/72270/20 "2010-11-12T17:02:16Z")
air to air intercooler plus meth = profit?