# AWIC - Any reason NOT to do it?



## thegave (Dec 22, 2008)

Bit of background - 
Full fat MK2 (aircon PAS) with FMIC behind grille and WMI. 

I feel like the FMIC behind the grille (in front of a/c condensor and rad) is causing serious heat in the bay and my car is going to be used in a pretty warm climate (high 80s). 

The only thing turning me off AWIC at the moment is to do with heatsoak, car is a daily and will probably spend lots of time in traffic. 

*Is AWIC a good idea?* The bay is pretty damn packed and I'm not sure where the heat exchanger could go.


----------



## mldouthi (Jun 26, 2010)

The heat exchanger would normally go in place of your FMIC. The heat from the system has to go somewhere, you would have to mount the heat exchanger not in the engine bay if you didnt want the heat to end up there. 

If your going to be sitting in traffic, and you do decide to go AW I would get some fans. Also a bigger coolant res. will help with heat soak, but then you are adding weight.


----------



## Filthydubber (May 7, 2007)

There are 2 good things about an AWIC. 

1) You can throw ice into the reservoir and get cooler IAT's than ambient air. 
2) Pressure drop across the core is very low. 

Heat transfer is worse than an convenctional IC as you have 2 heat exchangers instead of 1, and the system is much more complicated. 

I don't think that I would ever do one, but that is my opinion.


----------



## thegave (Dec 22, 2008)

I sort of assumed fans were a must regardless. 

Ice only really works for the strip and since there aren't any where I live I don't think I'll ever really be able to take advantage of that. 

For a moment I had the crazy idea of keeping the res _inside_ the car so it gets a little cooled by the aircon, but if I understand correctly the res needs to be at the highest point of the system? Which complicates mounting options. 

Part of the attraction is that I imagine the heat exchanger is smaller than a conventional AAIC so easier to mount in the bumper where it'll get the coolest fresh air. I just want something that's essentially more compact and more reliable for a dd in lots of stop and go traffic.


----------



## Filthydubber (May 7, 2007)

thegave said:


> I sort of assumed fans were a must regardless.
> 
> Ice only really works for the strip and since there aren't any where I live I don't think I'll ever really be able to take advantage of that.
> 
> ...


 The AWIC will be better in traffic to a point. Once the coolant is heat soaked, response on getting it cool again will actually be slower than if you just had the AAIC. I guess it depends on how long you are in traffic.


----------



## mldouthi (Jun 26, 2010)

The res. doesnt have to be the highest in the system. It just needs to be positioned in a way that it will always keep water supplied to the pump. Most pumps are designed to push the water and not pull it from a tank. All this means is the pump should be the lowest point in the system. 
An expansion/overflow tank is a good idea also, and that would have to be mounted above your res. (dont mean to offend, if you already know this)


----------



## stntman (Sep 19, 2002)

if you piece the system together well and have a good heat exchanger for the system youll be fine. i know that the new twin turbo v8s that bmw use are using awic and with the turbo being next to the cooler, living in phoenix, and driving in the summer you can put your hand right on it and its cool to the touch


----------



## thegave (Dec 22, 2008)

mldouthi said:


> The res. doesnt have to be the highest in the system. It just needs to be positioned in a way that it will always keep water supplied to the pump. Most pumps are designed to push the water and not pull it from a tank. All this means is the pump should be the lowest point in the system.
> An expansion/overflow tank is a good idea also, and that would have to be mounted above your res. (dont mean to offend, if you already know this)


 No I did not know but all knowledge is good knowledge. I assumed a reservoir performed the same function but sounds like pump has to be lower than res lower than expansion tank, so the expansion tank could maybe be put in the bay or trunk and the res somewhere in the passenger footwell. Sounds like an awful lot of water pipework.. 

Traffic is usually no more than 30 minutes of stop-go for a 3/4 mile but it gets up to 92'F in the summer. 

Here's a _really_ dumb question; why don't AWIC systems ever run off the existing engine coolant loop? Post rad, pre-engine of course.


----------



## pimS (Jan 7, 2009)

thegave said:


> No I did not know but all knowledge is good knowledge. I assumed a reservoir performed the same function but sounds like pump has to be lower than res lower than expansion tank, so the expansion tank could maybe be put in the bay or trunk and the res somewhere in the passenger footwell. Sounds like an awful lot of water pipework..
> 
> Traffic is usually no more than 30 minutes of stop-go for a 3/4 mile but it gets up to 92'F in the summer.
> 
> Here's a _really_ dumb question; why don't AWIC systems ever run off the existing engine coolant loop? Post rad, pre-engine of course.


 There is allready a lot of heat in the cars coolant system, so looping from that would -with no-doubt- result in higher intake temp's.


----------



## mldouthi (Jun 26, 2010)

thegave said:


> No I did not know but all knowledge is good knowledge. I assumed a reservoir performed the same function but sounds like pump has to be lower than res lower than expansion tank, so the expansion tank could maybe be put in the bay or trunk and the res somewhere in the passenger footwell. Sounds like an awful lot of water pipework..


 There are ways of doing this in a less complicated way. Such as running the res. in the spare tire well with the expansion mount back there as well. and the pump mount right under the res. Then all you have is 2 lines running from the front to the back.


----------



## Filthydubber (May 7, 2007)

thegave said:


> Here's a _really_ dumb question; why don't AWIC systems ever run off the existing engine coolant loop? Post rad, pre-engine of course.


 Even post radiator coolant temps are up over 120*


----------



## thegave (Dec 22, 2008)

Ahh shoot I just realized there's no where else in a MK2 to put the intercooler itself other than in the gap where the battery and washer fluid tank go, so that means I have to run a SRI with drivers side inlet?


----------



## sTT eV6 (Oct 26, 2010)

If you can relocate the battery it will free up some space. 
My reservoir is under the cross bar on the right and my pump is in place of where the AC was as it was convenient there.. 








Sizing is important to get the best efficiency. 
Steve


----------



## ncsumecheng (Nov 1, 2005)

There's good and bad info out there. Lot's of pros, only con is complexity.

Not good for road racing since you have the efficiency of 2 heat exchangers to deal with instead of just one.

However, for a street car it is perfect. You are constantly driving around or idling a very low engine load. During this time you are bringing your water darn close to atmospheric air temp. Then you do a run, and as we know water/air is more efficient than air/air.

So, drag/street is perfect. Road race would be a no go, since you're at 100% load for nearly 75% of the time.


----------



## REPOMAN (May 3, 2001)

I've used Water to air for Street Strip for over 10 years. works great 
The key to a good system is a large frontal area cooling core/heat exchanger.
I use the Allison Trans cooler from a duramax Diesel. 24" x 13" 
















Then a good pump. I use a Groco Live Well pump 17.5GPM @ 8amps.
With a resivoir it adds to the cooling effect about 20 deg F.
adding Ice in between rounds i can get lower than ambient air intake temps at 25+ psi.

My resivoir outlet is lower then my pump so i have a 1" one way check ball inbetween the res and the pump. My I/C i tapped a bleeder valve on the highest point to bleed off any air in the system.


----------



## chrgdVR (Aug 2, 2004)

inexpensive awic kit...anyone ever used one of these?


http://www.frozenboost.com/product_...=1034&osCsid=b768bc2678cfad4bafc73be92d29b0fb


----------



## thegave (Dec 22, 2008)

Longer boost piping => more lag right? 

Is there a difference in the path of the air through an AWIC and a AAIC? 

Cos I'd like to keep the standard 16v intake which means a similar length of pipework to a regular AAIC. Is that going to eliminate one of the biggest benefits of AWIC (less lag)?


----------



## sTT eV6 (Oct 26, 2010)

chrgdVR said:


> inexpensive awic kit...anyone ever used one of these?
> 
> 
> http://www.frozenboost.com/product_...=1034&osCsid=b768bc2678cfad4bafc73be92d29b0fb


Ive just fitted a 16" x 12" unit as i had a 12" x 12" but i have freed up some more space.
Steve


----------



## Vegeta Gti (Feb 13, 2003)

REPOMAN said:


> I've used Water to air for Street Strip for over 10 years. works great
> The key to a good system is a large frontal area cooling core/heat exchanger.
> I use the Allison Trans cooler from a duramax Diesel. 24" x 16"
> 
> ...


link to where you purchased that heat exchanger/trans cooler?


----------



## REPOMAN (May 3, 2001)

:thumbup:


----------



## REPOMAN (May 3, 2001)

This is the one i use. 20GPM flow rating

DB-1260 High flow cooler - 3/4" fitting, 24.0 x 13.0 x 1.5 Overall size 
Flow range 4 - 20 GPM 
Heat rejection range 28,000 - 38,000 BTU/Hr at 2500 FPM air flow 
Includes (2) DB-515-B mounting kits


You can source them here
http://www.makcotransmissionparts.com/DB-1260.html


----------



## thegave (Dec 22, 2008)

Another thought. With the pipework being so short on a AWIC engine is there still any need for the conventional 2 stage WMI setup since the meth from the first injector doesn't have very far to travel anyway?


----------



## aFOURstance (Jan 31, 2011)

frozenboost.com has some kits for fairly cheap, I've been looking at getting a set from them, anyone have any experience with them?


----------



## dasbeast3.0 (Aug 15, 2007)

People love them because they are very cheap, but the cores are pretty inefficient. Like anything else, you get what you pay for.


----------



## aFOURstance (Jan 31, 2011)

Any recommendation as to where to find quality cores?

Sent from my stupid phone


----------



## Rod Ratio (Jun 6, 2012)

Good info here subd:beer:


----------



## mldouthi (Jun 26, 2010)

aFOURstance said:


> Any recommendation as to where to find quality cores?
> 
> Sent from my stupid phone


Bell Intercoolers. 

Even though I had a recent bad (manufacturing problem) core from them, the cores are great quality and they stand behind there product. They have great customer service also.


----------



## bonesaw (Aug 8, 2004)

aFOURstance said:


> Any recommendation as to where to find quality cores?
> 
> Sent from my stupid phone


Spearco, bell, Garrett.


----------



## aFOURstance (Jan 31, 2011)

mldouthi said:


> Bell Intercoolers.
> 
> Even though I had a recent bad (manufacturing problem) core from them, the cores are great quality and they stand behind there product. They have great customer service also.





bonesaw said:


> Spearco, bell, Garrett.


Thanks guys, I'll look into all of them and do some measurements :thumbup:


----------



## mldouthi (Jun 26, 2010)

aFOURstance said:


> Thanks guys, I'll look into all of them and do some measurements :thumbup:


Bell has the biggest size variety. From what I remember looking up garrett and sparco only have a couple sizes of cores. Bell has thousands.

http://www.bellintercoolers.com/_pages/coreLiquidCore.html


----------

