Gaining 1-2psi oil pressure at idle must mean that the sharp turns in the factory whiteblock oil cooler must be really restrictive, and surprisingly the improved flow of the setrab parts must make up for the extra 8 feet of AN-10 hose that the engine oil now has to flow through above 180F. Against all recommendations from reputable online sources, the factory whiteblock routing appears to flow oil from pickup->oil pump->oil cooler->oil filter->engine block & turbo, which meant the oil flowing to the cooler was the port on the oil pan nearest the passenger side. My oil pressure sensor is at the factory location, and my oil temp sensor is in one of the blanked ports in the oil pan right after the oil pump. While very convenient, this threaded port is a short dead leg and is in pretty direct airflow on the highway which I think gives slightly low oil temp readings at highway speed. Seems like this happens to other people too.
This oil cooler fit nicely where the brake booster vacuum assist pump used to be. In new england, the very necessary Setrab oil thermostat works amazingly well without actually physically blocking flow to the cooler and instead relying on the oil taking the path of least resistance until closing at 180F and sending all oil to the cooler. I added some insulation to the thermostat and pre-thermostat hoses which helped a little in the winter, also keeping a foam plug in the oil cooler air intake duct does a great job keeping the overall oil temp over 180F even in 20 degree weather while commuting. According to BlackStone Labs this has so far not created any winter condensation issues in the oil, though I have noticed a sudden increase in oil varnish inside the engine, which has yet to be attributed to something.
Routing the Setrab fan exhaust towards the transmission seemed no less appropriate than the factory radiator exhausting directly onto the engine. I do wish I had picked a less awkward stack of fittings in order to include the 200F fan switch between the thermostat and the cooler. SendCutSend did a great job with the custom bracket I designed to mount the thermostat to the transmission, which all fits nicely above the factory skidplate, happy to provide the sheetmetal bend file for this. Building these Setrab 10-AN fittings was extremely easy, Pegasus Auto Racing obviously made this very easy to part out and assemble. McMaster-Carr-ing my way through machining the oil pan adapter plate and the black coolant manifold also turned out well, highly recommend going Fumoto valve crazy too.
The system has been daily driven for about 6 months with no issues so far, it has yet to be seen what kind of longevity the flexible bracketing and vibration isolators securing the oil cooler to the subframe will have. I assume most of the oil in the cooler and lines doesn’t get replaced during oil changes which I have just come to accept. An alternative would have been mounting the oil cooler sideways to drain its contents after engine shutoff, but I was afraid this would have to reprime itself after every startup and risk bearing damage etc. The upright orientation of the oil cooler forces more flow throughout the whole cooler anyway.
This 19-row series 1 setrab oil cooler fanpack is an improvement even over the whiteblock Focus RS oil cooler, I have yet to use it for autocross duty which I will report back on. It will probably be slightly inadequate for continuous track use since this cooler is undersized according to Setrab’s own sizing guide. Ultimately I don’t know if my oil cooler location is better than stacking it inline with the radiator/condenser/intercooler, that route seems much more popular and perhaps affords more cooling due to the extra space for a larger oil cooler, even if it shares airflow with the radiator etc. For a B5254T2, this setup does a decently better job than the factory cooler, rarely allowing oil temps over 200F on the road and potentially benefitting from a larger oil cooler in the future.
coolant manifold bolted to oil pan adapter plate
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tight routing to oil cooler
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3D printed fresh air hose to oil cooler, independent of radiator/intercooler/condenser
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oil cooler air intake
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oil cooler & fan placement and orientation, fan switch at right
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bottom view
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winter insulation on oil thermostat and pre-thermostat lines
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partially insulated oil temp sensor
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