the Dune Buggy Archives
DBA Forum - Not logged in
Previous Next Up Topic Engines / Subbug - Subaru Power / Water Cooled Turbo (6633 hits)
By Tom & Kathleen I 639 Date 2008-11-25 02:37
We are upgrading the Garret T3/T4 turbo in Kathleen's Manxter to a ball bearing & water cooled center section.  Where should the water come from to cool the turbo?  I am going to guess the cross over pipe on top of the engine and a pipe off of the thermostat lower hose.  But, I don't want to guess, I would like to get it right.  Thanks!  Tom
Tom & Kathleen Manxter #16, Kick-Out SS #16 & FiberFab Buggy
Manx Club #1030, CVA, RBC, SCCA
By Mel Adjusted Date 2008-11-25 08:40
I think your talking about the connections for the heater... If that is correct that would be a good place to tap into the water system...
At my age.. Everything I buy comes with a lifetime guarantee..
By @Jeff GS Date 2008-11-25 12:45
The factory turbo motors have the connections for this already - actually just need one connection and it is on the head, near the engine block and down somewhat near the oil drainback (from the turbo).  Maybe the 2.5 heads have this boss too, maybe with a plug in it?  The return water line goes directly into the water reservoir, so it doesn't need a return back to the engine itself.  This provides water "before" it gets heated by the engine, as opposed to the water crossover on top which is already heated, but if that's all that is available - use it!

Here's a pic of the 2.0L turbo engine layout, rear passenger side of the block.  Upper right (blue) AN fitting is turbo oil feed, lower AN is turbo water feed and the open tube just below that is the turbo oil drain.  You might look for these bosses on your heads, might have plugs in them that could easily be swapped out for fittings?

By @Jeff GS Date 2008-11-25 13:06 Edited 2008-11-25 13:24
Oops - just dawned on me you're running the turbo on the timing belt side of the engine!  DOH!

Only place I can think of on that end is back to the water crossover on top, or maybe one of the big plugs on the underside of the cylinders (one of which is used for the OEM turbo engine water connection for the oil cooler).  IIRC, the oil cooler is fed directly from a fitting at the water pump and returns at the plug in the block, but this plug "could" be used as a supply since it is under pressure from the pump - through the bottom side of the block.  This should be the same water passage way that is feeding the rear supply fitting in the pic above.

Those rear head connections would be pretty inconvenient for an opposite side mounted turbo as mounted on a rear engine buggy.

You could also use a temperature sensor adapter piece in the upper radiator hose, and use that sensor fitting for a water supply.  Not very clean though, and more hose connections to deal with.

By Tom & Kathleen I 639 Date 2008-12-08 23:16
OK - I just talked to Mac at Outfront.  When the engine was built, a thermostat was included.  This added a water line between the crossover pipe and the thermostat area on the bottom of the engine.  It currently runs behind the cam belts.  Mac said to cut into this line and run it thru the turbo water jacket.  Nice easy solution.  I will post pictures on the Austrailian Manx site when this is done.

On anther note, I was mistaken about the rebuild that was done on the turbo.  Because of the old design of the T3/T4, it was not possible to make it a ball bearing center section.  We were also told there is no similar sized "modern" turbo that will bolt up.  A smaller size will be needed which will require much rework of the existing exhaust and intake plumbing.  If the current turbo ever gives up, we will consider it then.  Tom
Tom & Kathleen Manxter #16, Kick-Out SS #16 & FiberFab Buggy
Manx Club #1030, CVA, RBC, SCCA
Previous Next Up Topic Engines / Subbug - Subaru Power / Water Cooled Turbo (6633 hits)

Powered by mwForum 2.10.2 © 1999-2007 Markus Wichitill