NC external oil cooler
According to Optimizing the Cooling System I need more cooling and have already identified that an external oil cooler is the low hanging fruit.
I have not found the perfect off the shelf kit which cover all my needs:
- Secure and low profile oil takeoff adapter with no filter relocate BS.
- Port for turbo oil feed.
- AN10 with minimum hose length and as few angled fittings for minimum pressure loss.
- Cooler mounted in fog light opening
- Price…
So DIY it is.
Oil filter housing
I wanted to avoid a sandwich plate as it can put a lot of strain on the aluminium threaded nipple for the filter.
Easy to overtighten as well as the typical extender/adapter has a tempting M24 hex.
Also the flow path of some of the adapters out there is less than optimal. Also no need for a thermostat.
So I opted to modify a spare OEM oil filter housing by adding some AN10 weld bungs to existing oil channel for the donut cooler.
They came in different versions dependent on production year/market:
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I never thought about how oil is flowing trough the filter/donut.
- Pump send oil down the oil gallery directly to adapter and into the donut cooler on top.
- Out of donut to the filter where it is pushed to the outside of the filter element
- Oil exits out the threaded hole in the filter and back into the block.
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I did some half-assed milling with a drill press to get something weldable. The existing holes are AN10 ID A professional welder did the actual welding.
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Tight fit with the 90 deg AN10 hose connectors:
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Lines and fittings
The lines were routed such that no more bends are needed to the oil cooler inlet/outlet.
The oil is fed from the bottom to avoid air pockets.
Outlet hose exits above the frame rail.
I will use a AN10 male/female 10mm sensor adapter inline after the cooler with a Bosch Pressure/Temp sensor.
The stock oil pressure port is used for turbo oil feed.
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Cooler
The 20? row cooler is positioned just in front of the fog light hole. Some ducting will be needed to get proper pressure differential.
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The air will exit wherever it wants to go. Initial testing in N/A form says it works too good for normal driving, so I ad to slap on a magnetic pad to not over cool on normal driving. Plan is to have 3D printed ducting for this which is plugged with the OEM fog light insert.
As I’m in the progress of switching both EMS and gearbox I will not see any track time before 2026 which is the real test. I will have a go at shimming the stock pump to increase oil pressure. It’s barely adequate in stock trim so I would say it’s a requirement when adding a cooler.
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