Come on ben, you didn't just throw the "basic wg" thread at me did you?
For ultimate durability the water-cooled center section is a must. Oil temps can still see coking temp inside the turbo when run really hard with oil that can't keep up.
Even if letting the car idle perfectly for a cool-down period, oil can still coke inside the center section because of the heat. It happens.
I don't think the diaphragm is really going to have coolant in contact with it. Looks like to me they cast a hollow part inside the case to keep it cooler.
For ultimate durability the water-cooled center section is a must. Oil temps can still see coking temp inside the turbo when run really hard with oil that can't keep up.
Even if letting the car idle perfectly for a cool-down period, oil can still coke inside the center section because of the heat. It happens.
I don't think the diaphragm is really going to have coolant in contact with it. Looks like to me they cast a hollow part inside the case to keep it cooler.