What oil temps are you getting on track?

[DanThe]

Just wired up my Audi gauges this morning, the oil temp gauge has a range of 60° up to 170° which doesnt read very accurate

Gauge on the right here -



Im expecting to have an average of around 90° with the S50 cooler fitted, chap I was talking to at Oulton was getting about that on his E36 evo, so I will be looking for a replacement gauge with 100° at the top centre on the dial.

Something like this


Sound about right?

[billgatese30]

Sounds about right to me. In the summer after a long track session (20 mins plus) then mine raises to about 100-110 degrees.

[Mikey_Boy]

At Oulton in September with an ambient temp of about 17 degrees, I was getting 110 degrees in the main gallery (hottest point), 110 degrees in the gearbox and 105 degrees in the diff... This was on a 325 sport with a standard oil cooler, running about 180hp revving to 6900rpm (remember that power output affects how much heat goes to oil as well as revs) - Stack gauges so I hope these are accurate!

If you are running decent synthetic oil, anything up to about 125 degrees in the engine main gallery is OK.

Cheers,
Mikey_Boy

[DanThe]

The sender is in the filter housing so the oil would be cooler there I imagine, thanks.

Do you have aux gauges Chris or one of those poncy sets of clocks

[billgatese30]

If you are running decent synthetic oil, anything up to about 125 degrees in the engine main gallery is OK.

Cheers,
Mikey_Boy

It is a case of matching your oil viscosity to your running temp too that is important.

[billgatese30]

The sender is in the filter housing so the oil would be cooler there I imagine, thanks.

Do you have aux gauges Chris or one of those poncy sets of clocks

Poncy clocks with the pink...errr.. I mean red needles

[bss325i]

Sounds about right to me. In the summer after a long track session (20 mins plus) then mine raises to about 100-110 degrees.

Yep, i was getting the same after a few laps of the ring two years ago when it was in the touring.

That was in the height of summer with ambient temps of 28-30.

[Mikey_Boy]

It is a case of matching your oil viscosity to your running temp too that is important.

Yes that's absolutely true - good point - remember though that the upper number of your oil (e.g. 5W50 or 5W30) refers to the viscosity at 100 degrees, so a 30 grade will be less viscous than the 50 grade at high temperatures.

When I was at Cosworth, we ran 5W30 oils to about 160 degrees to see when they started to degrade as part of oil system prove out, durabilty process and also to get an idea of what temperature the main and big end bearing film thickness went below the critical limit that had been set (normally below 1 micron), but this was a real extreme - so don't try this at home...!

Best sticking with higher viscosity grades for track use for a good factor of safety in case you encounter high temps.

[DanThe]

Out of interest, what temps did the 5w30 start to degrade?

[Mikey_Boy]

Depended on the oil brand if I remember correctly... Fully synthetic 5W50 was pretty bullet proof, running to 160 degrees (sump not gallery) for short excursions without any issue. 5W30 conventional mineral oil was good to about 130 degrees in the sump (not gallery) - then started to oxidise pretty badly. Remember though that when engines are being designed and developed, then it has to be 'protected' for the folks who will put the cheapest oils they can get their hands on during it's design life...

[e301988325i]

Sounds about right to me. In the summer after a long track session (20 mins plus) then mine raises to about 100-110 degrees.

The only time I've ever felt my standard BMW oil cooler hot is when the sump temp has got to these figures.