Coolant temps around 240 after four corners at COTA.

[kolosy]

Originally Posted by roastbeef

what does the underside of your splitter look like where the oil cooler outlet is? i imagine its pretty hard to make that area a high pressure zone, but without proper ducting, air might be just flowing around it.
the oem undertray on thse cars is decently form fitting with minimal leaks for what it is. i feel like distrupting the packaging is problematic.

I’ve got an mporium under tray on it. It’s got a rubber sealing strip that makes good contact with the bottom of the oil cooler. The lip ends just ahead of that with a 1-2” step up in the floor.

[DRLane]

Originally Posted by kolosy

I’ve got an mporium under tray on it. It’s got a rubber sealing strip that makes good contact with the bottom of the oil cooler. The lip ends just ahead of that with a 1-2” step up in the floor.

You’ve built a car that can be pushed harder on track, oil is going to climb s as will water. Expect 280+ sustained oil temps until ecu pulls redline. Cooling these has yet to be solved without one-off fabrication.

[bigjae1976]

Originally Posted by Redd

Since we're on this topic, what's the max SAFE coolant temp to be running at track? Mine hit 112C/234F momentarily after a few laps. I saw the warning on my HUD (no CEL/warning from DME) and immediately took a cool down lap. Both oil and coolant temps dropped quickly once I stopped pushing.

Safe temp is limited to the boiling point of water. 212f plus 3 degress for every PSIA.

Most OE systems run about 17psi? 263f would be the boiling point. You have to factor in once the car shuts down the coolant heats up in the engine and could boil and cause an issue.

Aluminum expansion tanks should have a higher pressure cap which provides a higher boiling point for an extra margin of safety. I think you can get a 29psi cap.

[bigjae1976]

Originally Posted by Lienrocs

I have no idea. I’ve had the car go into limp mode once before but it was pre can data integration so I don’t have real temp data. I know my F82 M4 sits around 220 in comfort/sport just driving down the freeway. I know it’s a different car/engine but BMW does BMW stuff.

Maybe try replacing the coolant sensors?

Originally Posted by kolosy

I’ve got an mporium under tray on it. It’s got a rubber sealing strip that makes good contact with the bottom of the oil cooler. The lip ends just ahead of that with a 1-2” step up in the floor.

Those flat panel under trays will get a lot less extraction from the oil cooler.

The OE part sits closer to the ground which creates a lower pressure zone.

There is also a large gurney on the front edge of the oil cooler exit ducting. I made a carbon undertray where the gurney flap is bonded on. Just street driving there is a 5 degree improvement by adding the gurney flap.

[Redd]

Originally Posted by bigjae1976

There is also a large gurney on the front edge of the oil cooler exit ducting. I made a carbon undertray where the gurney flap is bonded on. Just street driving there is a 5 degree improvement by adding the gurney flap.

Any pics of this gurney flap pls?

[bigjae1976]

Originally Posted by Redd

Any pics of this gurney flap pls?

Hard to see but it looks the same as the OE part which has a gurney integrated.

[Redd]

I see what you mean. I have an Mporium metal undertray. I shall see if I can stick a piece of rubber trim in the front of the opening to create a low pressure zone to evacuate hot air faster out from the oil cooler outlet. Thanks!