Liquid to air intercooler?

Redneck Truck

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In case anybody else has done some digging and wouldn't mind saving me some time, I'm in the market to decrease boost temperatures, engine bay clutter, and plumbing.

So how about a small unit (fluid intercoolers that support 350+hp are not that big) plumbed directly into the cooling system so the water leaves the radiator and immediately enters the intercooler? you'd have to plumb a charge pipe from the turbo to the IC and the IC to the EGR valve, and you could stuff the intercooler wherever it would fit, like a book in a bookshelf, rather than directly in the airflow from the front end.

The I/O boost fittings on the unit I'm referring to are 2.5", and while I don't know the air volume of such a unit, but it would seem that eliminating lots of piping from a turbo to a front mount and back to the firewall again would more than outweigh the loss resulting from employing an intercooler that's a little too big for your application.

My questions are:
- has anyone else employed such a setup?
- does anyone know the temperature and (preferably convenient) location of the coolest water in the cooling system?
- how about using the hoses for the EGR cooler to cool the intercooler instead?
- how cool does the water entering a fluid intercooler really need to be, in order to be effective? obviously there's a reason they have a separate cooling system, but what if it could be done at least almost as effectively without a separate cooling system?

what do yall think? i'm staring at this 350hp unit on frozenboost.com and about to pull the trigger. anybody have any thoughts before i start dumping money and experimenting?
 

mrchill

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I did plot this out. I would use a separate cooling system for it a the engine coolant is to hot most of the time to be useful. You can install a small radiator(heater core or such) in front of the traditional radiator and use that to cool the aftercooler. Leaving it in the stock location will allow no pipe changes and a stock appearance. One could even run a supercooler to give extra cooling when needed.
 

Redneck Truck

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i would like to use stock piping for cost and simplicity reasons, but i'd like to use a lot less stock piping.

for instance, the intercooler could sit right next to and above the turbocharger and connect with a small OEM elbow pipe (like the one connecting the chargepipe to the EGR), and then another elbow pipe from the intercooler to the egr.

ceramic coating, header wrap, fire sleeving, or a heat blanket could be used to insulate the intercooler from engine bay heat if it's an issue.

cooling hoses could run from the intercooler in its new location to the IC radiator, in the stock intercooler position. it would be even cooler if you could adapt the tanks on the stock intercooler to accept 1" coolant lines, so you could run your own cheap-ass heater hose from the intercooler to the radiator and back and attach it with run of the mill spring type or worm gear clamps like the oem stuff uses.

for a MAP sensor (since the current one would drown), a template of its stock mounting location could be made, and a plate machined that adapts it to the EGR inlet gasket mating surface on the bottom of the EGR valve.

not sure what I'd do about a reservoir or a pump, as I don't know how big a reservoir I'd need. would be interesting if you could use that 5L OEM+ washer fluid reservoir and pump, though I imagine you'd run into issues with heat soak and damage, as well as insufficient flow of the pump.

any ideas?
 

Drivbiwire

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Waste of time on a TDI...

If you really need more cooling install a PD150 Intercooler.
 

Tsquare86

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Just as a heads up bud Air to Air intercooler >>>>> than Air to Liquid intercooler. This is primarily due to the fact that the A/L intercooler is being cooled by a liquid at 190F (assuming you don't put in a separate liquid cooling system). Yes I understand that A/L is going to yield a more compact and efficient reduction in temperature of the charge air, but when compared to cooling with an A/A cooler that has an ambient temp of 70F the A/A cooler is going to win hands down. The only case where the A/A cooler may not win is when there is no cool air coming over the intercooler. This could be solved by adding some active system of forcing air over the intercooler when the car is not flying down the highway.
 

Ski in NC

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As tsquare said..A/L cooler will need you to split coolant flow and sub-cool a portion to get temps down anywhere near what a good A/A cooler can do. That's alot of engineering and plumbing and for little benefit. Go A/A and go bigger if you need to. A big A/A cooler exposed to road wind is super effective.
 

mrchill

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Of course the cooling must be separate. And not everyone lives in a place with 4 lane freeways and lots of cool air. IN these cases, A\W will be a benefit...not to mention fit. Put is a big A\A and 1\3 of it gets airflow. Just not enough area. I have several big front mounts I am working with, but I will also do an A\W for a comparison.
 

Redneck Truck

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that's why i asked about separate systems (how they tend to work, AFAIK). a separate system would have to operate at a temperature between that of ambient air and that of the highest charge temp (or heat soak, if applicable).

i remember reading that the oem intercooler has a thermal efficiency of 70-80%, while liquid ones are 90+. someone else verify that, because i'm not 100%.

the point is, the setup i'm suggesting is relatively inexpensive and a lot of it could be made from spare OEM or generic parts, the air volume after the turbo is (presumably) smaller, charge temps would be reduced, intake capacity would be increased, and the cooling system for the IC would be VERY easy to set up - a reservoir/pump assy, a radiator, an IC, and 4 or 5 hoses, just like a regular cooling system.
 

Bush Hopper

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its is definitely not to be considers cheap, or easy to do. I spend 40 hours building one, unless you want to rush the job and make it look like crap.

Most time consuming will be the brackets. Also, wiring it up is time consuming, to make it look nice, I integrated the pump and fun cables into the harness and my pumps or fans don't turn on until the engine builds oil presure.
 

Redneck Truck

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That would be great EMT, I would really appreciate any insight or warnings you've got too - i've never set anything like this up before.

my thing is that i'd rather make the system better than bigger, and more easily expandable too.
 

Redneck Truck

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that's a good idea using the signal from the oil pressure switch to power the relay for the pump/fan. does the fan turn off after a certain speed? brackets should be easy - i've got a server rack I plan to cut up that is 1/8" aluminum with M5 or M6 holes every 10mm or so and I've got access to a tig welder, plasma cutter, and i've got a sandblaster, so I should be in good shape as far as the fabrication goes. if I have to make my own intake tubing I'll have to buy stainless bends or something, but i'd just as soon use oem plastic/rubber hoses.
 

Redneck Truck

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I see, you put the IC where the old one was, cooled it elsewhere? i was hoping it was ok to use regular barb fittings. a lot of the vendors recommend NPT, BPT, or AN fittings - i could spend $70 or 80 in fittings and hose by the time it's all said and done, but with barbs I could be out for $20.

Nice TT wheels!
 

Bush Hopper

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Redneck Truck said:
that's a good idea using the signal from the oil pressure switch to power the relay for the pump/fan. does the fan turn off after a certain speed? brackets should be easy - i've got a server rack I plan to cut up that is 1/8" aluminum with M5 or M6 holes every 10mm or so and I've got access to a tig welder, plasma cutter, and i've got a sandblaster, so I should be in good shape as far as the fabrication goes. if I have to make my own intake tubing I'll have to buy stainless bends or something, but i'd just as soon use oem plastic/rubber hoses.
The fan and pump always stay on, never enough cooling. the more the better. I used all stainless steel brackets, with 10 mm bolts and a few 12mm bolts.
 
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Redneck Truck

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10 and 12mm bolts? that's sure as hell not coming loose. i'm a bigger fan of minimalistic, efficient engineering than overbuilding, but maybe one day i'll be sorry. so far i've been ok though :)
 

Bush Hopper

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Redneck Truck said:
10 and 12mm bolts? that's sure as hell not coming loose. i'm a bigger fan of minimalistic, efficient engineering than overbuilding, but maybe one day i'll be sorry. so far i've been ok though :)
sorry, I mean metric, haha, 10 mm bolt head ( for the socket ), so I guess its a m5 or m6 actual bolt. Overbuilding is always a good idea, specially with the brackets. Must be mounted very well.
 
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Redneck Truck

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you were starting to scare me! why not just drill/tap some 14mm holes and countersink the flange and you can run acorn lug bolts :) cheap, beefy hardware.
 

G60ING

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I've built an air to water IC for one of my G60 corrados. They are complex (for under the hood) and best used for in drag racing enviroments or where the use of a front mount is not possible. In the future do not plan to make another A>W setup. A>A is simple and works well.

I will say that the IC plumb was only 18" as opposed to 5' on my G60. I think that this has an efect on the tuning that needs to be taken into consideration. Boost to fast and you may not have the correct level of fueling and could hurt things.
 

JPDiesel

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I was thinking about w/a intercooler and came up with this kit for about half the cost of frontmount. www.frozenboost.com The small one is supposed to be good for 350 HP and 70 psi boost. Anyone try this kit? The 350 HP rating is probably for a gasser. With the higher boost levels and therefore greater compressed air temperatures of diesels, this rating probably would be less for our diesels.
 

D_Bat

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For performance a/w wins assuming you aren't setting it up some a$$ backwards way and using the coolant for your car as the coolant for your a/w system. I've made an a/w setup and plan on making another for my VRT. My TDI is getting an a/a front mount though. Reason being is cost. Boost tubing is shorter with an a/w and cooling is better but my TDI is a daily and not a performance beast. The best thing with the a/w setup is that it's really stable and temps usually don't rise at all and stay about the same no matter how much you beat on it. Also you can throw in ice water if you are planning on racing.

Yes it usually involves a few more items if the installer takes his time to install the a/w setup it can look just as clean as a a/a setup.

My a/w setup is composed of the following.
a/w core - 16"x3.5"x12"
heat exchanger - aluminum radiator, the size of the stock a/c condensor
pump - Jabsco marine pump rated at 21gpm@2psi and 17gpm@6psi
hose - 1/2 or 3/4", I forget
5gal liquid reservoir
 

D_Bat

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Those cheap kits are usually good but... you'll notice they don't include the whole thing for a good kit.

You are missing hosing and a fluid reservoir. The fluid reservoir is essential to keep temps stable and low all the time. That radiator they show is the same one I used. That core they use is an ebay core and they perform great. I'm using an ebay core too but bigger than the one in that kit.

Lastly their pump is little to be desired. It is plastic and doesn't flow very much. I went overkill on the flow of my pump but that thing is just crap. I mention the plastic part because if you want this in something that is going to be running every day then I bet it'll fall apart and die. It will be getting heated up and cooled down constantly and it won't be able to handle your coolant flow needs. I spent 200 bucks on my pump alone.
 

k_harley

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I used to have a 1990 Celica Alltrac with a 1997 GT-Four swap in it. That came with a factory water to air intercooler.

It used a heat exchanger larger than the radiator, but thinner. Had a water pump about the size of an RV water pump for a sink, and tubing was 3/4" IIRC. Pump only ran when throttle was open, then shut off after about 90 seconds of non throttle. This was a factory program.

The big advantage was that the core sat right on top of the engine so the boost path was like.....12" long from turbo to intake manifold. Yes, bost was strong at low rpms, ct20b turbo was good for about 320hp, regular journal bearing, so I wouldnt call it a small turbo.

That was a homologated rally car, so it made sense to go water to air since rallying is lower speeds, dirty, and pretty hazardous to the front of your car.

Never compared it to a front mount, but the stock setup was an air to air on top the engine, which would get really heat soaked if you were in traffic, fine if moving 30mph+.

Yes, water to air CAN be more effective than air to air. Its a little more complex, expensive, and heavier.
 
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