Posted 25 March 2016 - 11:10 PM
Factory routing for the Z31 was housing below thermostat, turbo, water pump inlet.
Yes, you recycle coolant. That factory bypass line? USE THAT! No more recirculation than you already have, and in fact beneficial to your turbo.
Because during running, before the thermostat opens, you route recirculated coolant through the turbo back to pump inlet, aiding in cavitation prevention and hastening warmup.
Once that thermostat opens though, there is only the water pump NPSH to circulate water through there.... No big shakes, water flows center section is cool.
After shutdown, you have cap pressure blanketing the system. No pump suction to draw from the thermostat housing through the turbo back to the inlet...
What you DO HAVE, though, is blanket pressure and radiator-cooled water sitting at the water pump inlet. And the boiling hot turbo heating water upstream in that line...heated water which rises to and out the still-opened thermostat and out to the radiator...drawing cool water from the water pump inlet line through a thermal siphon...introducing the coolest water in the system available after shutdown through the turbo until the turbo housing reaches stasis with the water temperature.
When do you form Coke in the turbo, when running or after a heat-soaked shutdown?
This routing insures cool water being drawn through the turbo with no other devices present, at the time the turbo MOST needs this cooling to prevent temperature rise.
During running, water flows thermostat housing to pump inlet via pressure differential.
After running, water flow reverses and continues, pump inlet to thermostat housing and out to radiator via thermal siphon.
Think about the above for a while before making the hose routing changes suggested otherwise. You got what you need already there. You don't change anything by using the existing bypass line in this manner.
Misanthropic Anthroparion Class 5 Hoarder, aspiring to posthumous fame as my containers are cut open and the market floods with crap I've squirrelled away over the years! I endeavour to persevere...