High oil temperaturs during my track event

[zoomzoom]

Originally Posted By: RI_RS4
I've seen oil temperatures of 278F consistently at Watkins Glen and Mont Tremblant in the RS4. This is not an issue, as long as the oil flashpoint has not been reduced by fuel dilution. Good synthetics will easily handle 290-300F continuously. But with dilution, there can be some significant burn off and deposit formation to look out for.

In my RS4, I was able to run 10K mile on RLI Biosyn, which included 4 track days at two events with the Audi club.


I am running GC 0W-30 and using the on line viscosity calculator looks like GC viscosity was 5.3 at 280F/130C temperature that I saw during my event.

That is pretty big drop from 12.1 at 100C that oil would be during normal daily driving.

How does oil ability to protect changes with such viscosity drop and increase of stress on the engine during the event?

I guess answer will come when I dump this oil and do UOA...

 

[addyguy]

I'm not trying to be a 'thickhead', but if it were my car, I'd be running a 50-weight. Turbo's add not only a lot of heat stress, but also a lot of shearing forces in their bearings. I don't have any engineering taining to back this up, but I just wouldn't take the chance.

There are a lot of got 5W-50 and 15W-50 oils that will have good start-up protection as well. Syntec 5W-50, M1 15W-50...maybe this is a good application for Amsoil's new RD 50 15W-50 race oil?

 

[Steve S]

That is why the choice of viscosity is important in relation to the ambient temps and the operation temps. The oil pressure is the tool to use in most all cases.

 

[zoomzoom]

these are not ball bearing turbos..so no sharing of oil there

 

[zoomzoom]

Originally Posted By: Steve S
That is why the choice of viscosity is important in relation to the ambient temps and the operation temps. The oil pressure is the tool to use in most all cases.


well car has no oil pressure gauge but it does have a low oil pressure warning that didn't come on even when idling when I just got of the track with oil temp at 280F?

 

[Steve S]

Originally Posted By: addyguy
I'm not trying to be a 'thickhead', but if it were my car, I'd be running a 50-weight. Turbo's add not only a lot of heat stress, but also a lot of shearing forces in their bearings. I don't have any engineering taining to back this up, but I just wouldn't take the chance.

There are a lot of got 5W-50 and 15W-50 oils that will have good start-up protection as well. Syntec 5W-50, M1 15W-50...maybe this is a good application for Amsoil's new RD 50 15W-50 race oil?
What start up proctection are you getting from a 5w-50 oil if the ambient temps aren't low enough to need a 5w oil in a racing type of use and the multi visc oils shearing potential.

 

[zoomzoom]

I wonder has any of you track gurus seen a reduction in oil temperatures by using thinner oil such as redline 5w20?

 

[aquariuscsm]

All of the people I know who track their TT Z32`s use only 20W50`s.

 

[zoomzoom]

Originally Posted By: aquariuscsm
All of the people I know who track their TT Z32`s use only 20W50`s.


I know most people who track their cars use thicker oil, but I was wondering does anyone know of instance where they went with thinner oil and actually lowered their oil temps on track when running under same condition and using heavier/thicker oil?

 

[HTSS_TR]

Why don't you try thinner oil for the next track event to verify that it would lower oil temperature ?

 

[zoomzoom]

Originally Posted By: HTSS_TR
Why don't you try thinner oil for the next track event to verify that it would lower oil temperature ?


I am thinking about it but would like to verify that some people have done it with success and without blowing up their engine

 

[sprintman]

Redline 10W40, M1 15W50, or the new Amsoil racing which I can't remember the viscosity. 0W30 for track days, not for me I'm afraid...s

 

[RI_RS4]

Originally Posted By: zoomzoom
Originally Posted By: HTSS_TR
Why don't you try thinner oil for the next track event to verify that it would lower oil temperature ?


I am thinking about it but would like to verify that some people have done it with success and without blowing up their engine


Why not try science? Since you track your engine, it's a good idea to understand what the oil is doing, to know whether you can affect a change in oil temperature by changing viscosity. I'd take a UOA sample before the car was tracked following a normal drive cycle (say the one that got you to the track, and then one right after it comes off the track. Then have it analyzed somewhere that performs accurate analysis of fuel dilution.

Audi's engines are designed to run hot, which is why 5W30 and 5W40 oils with high HTHS are specified. At 180F (140C) your viscosity is about 1/2 of the 100C viscosity that the engine is designed to run at under normal loads. An oil with a high viscosity index will help to reduce this spread.

As a point of reference, my RS4 engine ran 178F at Watkins Glen running RLI Biosyn 5W40 one time and RLI Biosyn SAE40 another. I ran the SAE40 for two 2-day track events at Watkins Glen and Mt. Tremblant, without changing, and put almost 10K miles on the oil, with no adverse effects, and better wear performance than "502-approved" oils.

 

[hooligan24]

I just got done doing some comparing with a viscosity index calculator with M1 0w40 and redline 10w40. once the two oils get to around 270oF, the viscosities are nearly exact according to the calculator. up until that point, the redline is a little thicker. The last event I attended, I was seeing 270-280oF temps with the redline 10w40 in my Turbocharged 4 cyl.

Between the two oils, which would you guys prefer to use for 30 minute sessions on the track?

 

[zoomzoom]

Originally Posted By: hooligan24
I just got done doing some comparing with a viscosity index calculator with M1 0w40 and redline 10w40. once the two oils get to around 270oF, the viscosities are nearly exact according to the calculator. up until that point, the redline is a little thicker. The last event I attended, I was seeing 270-280oF temps with the redline 10w40 in my Turbocharged 4 cyl.

Between the two oils, which would you guys prefer to use for 30 minute sessions on the track?


I doubt their viscosity is same at that temperature...M1 has HTHS of 3.6 and Redline has 4.7, remeber HTHS is taken at 150C..

I am wondering is HTHS viscosity most important property of oil as far as track use is concerned?

 

[zoomzoom]

Originally Posted By: RI_RS4
Originally Posted By: zoomzoom
Originally Posted By: HTSS_TR
Why don't you try thinner oil for the next track event to verify that it would lower oil temperature ?


I am thinking about it but would like to verify that some people have done it with success and without blowing up their engine


Why not try science? Since you track your engine, it's a good idea to understand what the oil is doing, to know whether you can affect a change in oil temperature by changing viscosity. I'd take a UOA sample before the car was tracked following a normal drive cycle (say the one that got you to the track, and then one right after it comes off the track. Then have it analyzed somewhere that performs accurate analysis of fuel dilution.

Audi's engines are designed to run hot, which is why 5W30 and 5W40 oils with high HTHS are specified. At 180F (140C) your viscosity is about 1/2 of the 100C viscosity that the engine is designed to run at under normal loads. An oil with a high viscosity index will help to reduce this spread.

As a point of reference, my RS4 engine ran 178F at Watkins Glen running RLI Biosyn 5W40 one time and RLI Biosyn SAE40 another. I ran the SAE40 for two 2-day track events at Watkins Glen and Mt. Tremblant, without changing, and put almost 10K miles on the oil, with no adverse effects, and better wear performance than "502-approved" oils.


Well oil used in that track event(GC 0w-30) is nearing 5K miles and will be changed pretty soon. I am sending a sample for oil analysis so we will see what impact if any these high temps had on wear as compared to my previous OCIs with same oil.

so far GC feared pretty well in this engine that is modified to run twice the stock boost in street configuration...

 

[RI_RS4]

That's always been a nice engine. I don't see much to worry about, unless the next UOA comes back with something off.

 

[zoomzoom]

Just changed oil yesterday and sent sample to Blackstone..I am very curious to see the results...

 

[zoomzoom]

UOA came back with clean bill of health, GC held up just fine with track abuse followed by 5K(changed oil just before track event) of regular driving,number cold starts and some long distance trips.

Thumbs up for GC

 

[RI_RS4]

Like I said, a very nice engine that's well over-designed. There are quite a few of them running around putting out 400-500 HP