Transmission Oil as a cooling medium

[Lextreme II]

I am doing a little side project using the rear mount method. However, I noticed the transmission lines and pan is right near the turbo. I wonder if it is ok or feasible to use transmission oil as a turbo lub and cooling medium. If I am able to use transmission oil for that purpose, then I will surely put in a tran cooler. Any feedback will help alot.

Thanks
david

 

[puredrifter]

I definitely wouldnt, the fluid isnt made to cool something as small+hot (low surface area) as a turbo and would prolly just coke up or burn.

its the same reason u dont put trans. oil in ur crankcase

 

[v8huntr]

dave,

i would say no because if temp difference between engine and trans oil. it really isn't that much more work to run the oil feed line to rear or the car. since you are doing rear mount you'll need to use pump for oil return.

 

[cribbj]

David, why don't you contact Garrett or Turbonetics and get their opinions?

The flash point of a good synthetic ATF and motor oil are not that different, and ATF's and their derivatives are well known for their ability to lubricate pumps, turbines, etc.

I would be concerned about the possible coking problem when you shut down after a hard run, then that crud getting swept into the A/T where it could plug the tiny passages in your valve body. You might have to install an inline filter in your A/T system, as well as a cooler.

 

[Lextreme II]

Thanks John,

Here is an interesting article I found about ATF and Temp. Looks like the operation temperature for both transmission and the engine is about 185-200 F. If I use full synthetic oil might give more heat tolerance. By adding a turbo to a N/A car. I wonder how much more heat the turbo would generate. Another factor I am also concern about would be the cooling factor. Typical oil is 4-5 quarts but transmission oil is about 2-3 quarts. Mobil One Synthetic oil is rated at 239 C.

 

[XR8tt]

If the turbo is going to be low or rear mounted? Then in most cases a trans pump is required to return oil to engine...
Then why not just have small sump under turbo and use this pump to circulate on its own lube???
Its just a matter of joining the oil lines together and a vent in sump to preven too much pump vacuum on turbo seals ...

 

[Lextreme II]

The turbo is rear mount but above the transmission pan. The tranmission oil line is right above the turbo and the pan is right below the turbo. I would assume with a large oil cooler and an oil filter would increase the ATF volume for better cooling.

 

[SCV8]

I would have a dedicated oil system just for the turbos, and a pressure switch that will shut off fuel/spark if there's no pressure.

 

[XR8tt]

I would have a dedicated oil system just for the turbos, and a pressure switch that will shut off fuel/spark if there's no pressure.

Yes you'll need something like that anyway with just an electric pump for return..
I can't see an easy way of ATF being used to cool only..
I can see a small oil cooler doing it though....