This is a write up on how I went about it and the results I saw in charge temp drop with the cooler installed.
If you aren't aware the charge temp out of a stock CT20 at 10psi under full load is up between 90 and 100 degrees C (measured with a K type thermocouple in the crossover pipe).
When I discovered this I decided to investigate the various options for intercooling.
In my forum searches I found the top mount air to air intercooler install to be the most common but because I don't have a body lift and I didn't want to obstruct the oil filler which most top mounts seem to do.
After recently turning my flogged out AC system into an on-board air setup I had the AC condensor that mounts in front of the radiator left over which I thought would make a perfect water to air radiator (with the addition of a couple of brass elbow fittings).
After a long period of ebay searching and looking at the frozenboost.com website I stumbled onto a cheap ($40) ready made water to air cooler that came off a Subaru Liberty / Legacy from the early '90s.
I got the measurements of the cooler and did some test fits with cardboard to see if I could fit it into the LN106.
This is the cooler I ended up with:
Aside from the Intercooler and heat exchanger the other main part needed is a water pump. I found on another forum that someone had used a pump model DC50D-1240 which can be had on ebay for $60. Most other pumps that are sold specifically for water to air setups are at least $100.
It draws 3.8 amps and flows upto 35L/min (at zero head pressure) and around 15L at 2m head which is the same spec as the Subaru pump.
With a life of over 30,000hrs it will last a while and is the right price.
http://cgi.ebay.com.au/ws/eBayISAPI.dll ... 1174539988
The other parts I needed were:
Heater hose - 5/8" or 16mm
Brass fittings to suit the hose and the AC condensor
Relay, wire and fuse for the electrical connection to the pump
Hose clamps
Silicone elbows / adaptors
I also bought a dual thermo couple reader for $30 as I wanted to put a thermocouple into the inlet and outlet of the intercooler so I could see the temp drop in the charge.
This part isn't really needed but I was interested to be able to measure the difference the cooler made to the charge temps.
http://www.ebay.com.au/itm/Dual-Two-Cha ... 0904447168
On to the install...
First thing I did was fit my brass elbows into the AC condensor. The condensor is a soft alloy so it was relativley easy to thread the fittings into it. I used some plumbing liquid thread sealer for good measure.
Next I had to modify my airbox and intake (low pressure) crossover pipe to allow the intercooler to sit in position.
This is how the engine bay looked before the install. I had to move the air connection / gauge from my on board air system, my oil catch can and duck the crossover under the intercooler.
Crossover cut - I used the old moulded rubber hose that used to connect the air box to the intake before I fitted the turbo but it is hidden under the intercooler.
And how it looked when done.
When I installed my turbo I had removed the stock 3L intake manifold and replaced it with the one from the Surf which has a vertical intake to suit the turbo crossover pipe. Because of the way I had planned to connect the intercooler I had to revert back to the side intake stock 3L manifold.
Off came the intake manifold and a new gasket was fitted before putting the original 3L intake back on.
I pulled out the fitting that was previously used in the top of the manifold for the PCV / breather to vent into and used a brass fitting that would turn this into the boost gauge connection.
This image shows how the intercooler will connect, using a silicone reducer, to the stock 3L manifold.
Doing it this way is effectively running the intercooler 'backwards' to how it runs on the Subaru. That is the 2" inlet on the bottom of the cooler is now the outlet for the Hilux install. The larger outlet on the side of the intercooler is now the inlet for the Hilux install. I had to use silicone reducers to fit it up but this was by far the easier way to install the intercooler and it doesn't really make much difference which way the air runs through it.
Next I focused on the electrics and plumbing of the intercooler, heat exchanger and pump.
Since I was using the AC condensor as my heat exchanger it had a ready made mounting pint in front of the radiator.
Also measuring 600 x 280 x 20 the AC condensor makes a fairly large heat exchanger.
Here it is mounted with the hoses connected up.
I mounted the water pump to my stone guard that sits under the engine as it allows easy access to the pump and places it at the lowest point in the system.
For the electrical system I used a fused direct connection to the battery through a relay that is powered up when the engine is on. So the pump runs whenever the ignition is on.
The intercooler position also required the fuel filter to be moved slightly. I used the fuel filter mount to secure the intercooler and another mount point (not shown) down to the air box mount at the other end.
This pic shows the mount while I was making it - before it was welded and painted.
And these pics are of the finished install.
In this pic you can see one of the thermocouples where it enters the crossover pipe before the intercooler. there is another one on the outlet to the intecooler.
Now for the results.
I did some before and after tests for EGT's but they are a little subjective as you can never really replicate the exact conditions doing a before and after. I found that the intercooler was good for around a 50c drop in EGT's (measuered before the turbo).
I was able to get reliable info on the drop in charge temp as I had the dual thermocouple setup that shows me the difference in temps between inlet and outlet.
So far the max difference I have seen is a 60c reduction as shown below. This figure was on the slight uphill section of Gympie rd at Carseldine (in BNE) on the run up to the last set of lights (Beams Rd) before you hit the Gateway / Gympie rd merge. I dare say it could go even higher on say the long pull up the Gateway bridge.
I haven't done any off road yet so not sure what I'll see there but at regular cruising speeds I see between -20 and -30c temp difference and around -10 when no load / boost.
Next thing I plan to do is wind the fuel screw in a touch to get some more performance now that I have -50c EGT's. I've been meaning to get a ball-check boost control valve. Mainly to stop waste gate creep but also to give it a coupe of psi more than the stock 9 (maybe 11 or 12 max).
I will also mount the thermometer somewhere more permanent as at the moment it just sits on the floor where it was easiest to get the thermocouples to through the firewall.
