Disclaimer: I drive a 1gen xB.

I'm using the Greddy turbo which uses a Mitsubishi TF035-HL-14GK. The Greddy kit does not include coolant lines or advertise a water jacket. However, this turbo is also used in OEM applications for Mitsubishi, including the 3.2L Pajero and Canter. The Canter is listed as having a water jacket.

On the center section, there is also two open threaded screw holes on the top, and two small freeze plugs on the bottom. I'm assuming this is where the water lines attach and I'm not sure if flow direction matters.

My question is, on the engine-side, where is the best place to tap into the coolant feed and return. Can I t-tap from the engine block draincock and feed it into the upper radiator hose where I have a metal coupler installed for a water temp sensor? Someone suggested tapping off of the heater core lines or the ones by the throttle body.

Water-cooled turbo guys, can ya help me out?

EDIT: I got pics now.

Here is the front side, the two taps are where the water lines go I believe.


And the opposite side facing the block with the freeze plugs

 

I ran mine inline with the throttle body water lines.

Very simple to do and you only have to cut one line.

 

i used cut 2 lines on mine but yeah on the throttle body coolant line

 

Did you run a T from the feed and one for the return?

 

yeah thats what i did

 

You think there will be an issue feeding enough coolant to the turbo?

 

well the way i looked at it is....

if you have a T on 2 lines, both with flowing water. I figure that the water in the turbo may get trapped and just not flow through it enough. If that makes since.

What I did is run the turbo "inline" with the throttle body return line. So the water coming out of the throttle goes through the turbo before returning to the "water system". That way I know I'm getting good flow.

 

^^ i've been thinking about that i just didnt bother changing it lol.. Basically my turbo coolant lines is a bypass line between the two TB lines.. im gonna be redoing it soon

 

Sounds like that's my answer then. Thanks guys. I'll t-tap in line with the TB return. Not too worred about flow, it's got to be better than the "nothing" Greddy has with the stock kit.

 

Anyone know if it matters which port I use for the inlet and which I use for the outlet? I called Greddy and they weren't aware it could even be water cooled until i pointed out the freeze plugs. They go through Trust to get the Mitsubishi turbo's so I don't have a stateside contact for Mitsubishi Heavy Industries.

 

it shouldnt matter.. but ideally if you could clock the turbo with one port sitting lower than the other that would be nice.. so the lower port would be the inlet and the higher port would be the outlet

 

Update, I gave a call to Mitsubishi Engine America, and they confirmed that the TF035 came in two versions, one with and one without water cooling. With the freeze plugs present, this one definately has water cooling available. They also said it could be ran in either direction, so I don't neet to worry about which port is the inlet. Looks like I may have the first water-cooled Greddy turbo on an xB.

I would have posted this in the xB section but given that neither the HKS or Greddy are advertised as water cooled I wouldn't get much of a response.

 

yup but try to do like i said, that way you would take advantage more of the "thermal siphon" thingy lol

 

Care to explain this "thermal siphon" theory of yours? Why would port location even matter, flow rate would be the same as you're talking a 2" spacing max for gravity feed. One port is higher, the oil feed tap sits on top when mounted. The lines would face out away from the block.

 

thermal siphon is not my theory.. i read somewhere book and somewhere here on the net.. its when you shut down your car, the heat from your turbo boils the water and pushes it out. As the water goes out, your inlet port will feed coolant to the turbo and the cycle goes until enough heat is taken away from the turbo. having a low and high port allows better flow of coolant when the car is off and prevents air pockets from staying inside the turbo water housing allowing more coolant to flow to do heat exchange

 

Thanks for bringing up the thermal siphon principle. I didn't really understand it from your description but I looked on Honeywell's post and they explained it a bit better. They noted that water cooling doesn't pull much heat during engine operation, only after shutdown. In order for the thermal siphon to work properly, the center housing needs to be BELOW the water level. Since my turbo is top mount, this won't work for me, though I believe I can still use it to gain nominal cooling when the water pump is active. I will be using a turbo timer so the engine will still run for a set time after the key is pulled, this should keep both the water and oil pump running to cool the bearings at shutdown.

Honeywell FAQ

Top mount, stupid Toyota making the exhaust manifold next to the firewall.


Q. What water flow rates are acceptable for turbo operation?
A. Water-cooling of turbocharger bearing housings has been widely used to enhance bearing durability. It is designed to remove heat from the center housing after the engine is shut down. This is accomplished because a thermal siphon is set up in the center housing. As heat from the turbine housing and exhaust manifold soaks into the center housing, the water is vaporized and rises, drawing in cooler water. This continues until there is insufficient heat to cause the process to continue.

Installation
In order for the water-cooling to function properly, the center housing needs to be installed below the water level in the engine. The water inlet to the turbocharger needs to come from a lower point in the cooling system up to the center housing. The water outlet needs to go from the turbocharger up to a higher point in the system and cannot have any high spots or "traps" in the line.

The center housing has four water fitting locations. Two of these should be selected such that they are on opposite sides of the housing and the water inlet is lower than the water outlet. The other two locations should be sealed off. These items help ensure that the water-cooling will function properly and the necessary thermal siphoning will take place. Please note the inlet and outlet connections for the water hoses on the drawings provided. If the turbocharger were installed without the water lines being connected, the unit will operate at temperatures similar to, or slightly higher than, the current non-water-cooled unit. However, the water-cooled center housings could be run on engine tests without the water lines connected with no adverse effects, provided the engine is cooled down adequately prior to shut down.

Flow Requirements
There are no set flow requirements for the cooling water, since the majority of cooling in the center housing is done by the lubricating oil while the engine is operating. The most important water-cooling takes place after engine shutdown, at which time the flow of water is a function of the thermal siphon and the flow rate is low. Therefore, the water lines to and from the turbocharger can be sized conveniently. The flow restriction through the center housing is negligible and so would not be of concern for the cooling system capacity.

Sealing
The water and oil passages are separate cast passages, so there are no seals to worry about. The passages are pressure checked on the assembly line to ensure casting integrity.

 

This is where I did my coolant lines:

 

I did the same as well. It has two lines a feed and return both lines connected directly to the turbo without using a T and the other as well. This way it flows as it is intended. I would recommend doing it this way. I have bypassed the tb coolant lines before without having issues in the cold this is why I did it again.

 

question, based on the pic above.. which one is the TB coolant feed and coolant return?

 

I didn't use the TB lines. I used the ones off the block to the heater core.