Questions about oil + turbo.

[PanzerAce]

I'm planning out my L30et build right now, and I was wondering if anybody could help with some the two (or two and a half) questions I can't seem to answer.

 

The first: How are oil coolers usually tied into the oil circuit? In my case, I have an AMSOil dual filter setup, so would it be best to just hook the oil in line for the cooler to the out line for the filters, and then out from the cooler to where the filter setup currently dumps back into the block?

 

Second: I'm worried about the turbo burning the oil up and turning it to coke when I shut the engine down. I know that there are basically two methods of dealing with this: letting the car idle for a few minutes to let the temps come down, or hookup some kind of pump/thermostat to continue to circulate the oil untill there isn't a risk anymore. I often don't have time to sit in the car waiting for it to idle, so what is the best way to go about hooking up some kind of cooldown system to the turbo?

 

Second (and a half): Since I'm writing this anyway, how are the oil lines usually hooked up to the turbo when coming from a P90 head?

[Tony D]

Pump, Oil Thermostat (bypass to filter), Cooler, Filter, Block Service Port.

 

Best if you run an oilstat to keep from overcooling your oil. You do want some heat in it!

 

You forgot the third alternative: Turbo Timer. Set your parking brake, turn your key off, remove it and yourself from the car and walk away. Automatically turns itself off after a requisite timed period.

Or Running a water cooled turbo, where the suction side of the water pump can thermal siphon throug the turbo after shutdown, and cool it with water as well. Synthetics are resistant to coking, hence their popularity with turbo owners, amongst other items...

 

The P90 head hasn't anything to do with oil routing lines. The block has an adapter for the oil cooler on it, and the lines come from there. Gozeouta and Gozinta fittings I believe is the technical jargon used to refer to them...

[PanzerAce]

ok, so for the piping, seems that just doing the reverse of what I said (basically) is fine?

 

So a turbo timer keeps the engine running until it cools off enough?

 

Do you have a place I could read up on water cooled turbos? I see a bunch of threads in various forums on the subject, but they are all of the 'how do I actually hook this up' variety, rather than the design of them, etc.

[Tony D]

Design is identical to what you have. Z31's used the same center section but it simply had a separate cavity to run coolant through as well as the oil. I have seen several 'water cooled' center section turbos installed into early cars in the early 'stock' configuration---they water cooling is supplementary, they still work as oil cooled only in this instance.

 

Some other turbos may depend more on water flow to cool them, but I doubt it. The way most are set up, it's as a thermal siphon for after shutdown post cooling through simple 'percolation' of the coolant through the body. Once the thermostat opens in that configuration, there really is little water flow through the circuit, and that which does occur is of hot coolant back through the turbo to the inlet of the water pump on pressure differential, not so much of a 'forced flow' like in the block.

 

Garrett/AiResearch probably has FAQ and Information on their stuff online, as I recall they have a decent tech section, but forget what all is covered by it. You can check it out here:

www.turbobygarrett.com