991 Engine Temps
06-18-2018, 08:08 PM
#1
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991 Engine Temps
I'm trying to collect some data on maximum track day engine temps that fellow 991 owners see. Would be best to know ambient temperature, max engine temp seen, and track this occurred on. While it would be nice to collect GT3 data as well, this is mostly targeted towards Carrera Models (C2, C4, C2, C2S, GTS, etc.). It's my understanding that the oiling system in the Carrera differs quite a bit from the GT3.
This past weekend I was at WGI. It was 93 degrees (low humidity) and I saw 261 degrees (oil temp). Last year in August at Summit Point (temp in the high 90's) I saw 278 degrees. This was on the MFD that provides a numerical value and a position on a bar graph. While these values seem high I noticed that the indicator was still quite a way from maximum, I'm guessing the maximum is around 300 degrees.
I do not have a center radiator yet (being installed in July) and was wondering what others are finding. Discussing this with folks in the paddock we all agreed that we didn't know that much about the internals of the 9A1 engine and that newer cars purposely run warmer for more efficient emissions. This then leads to the question, are these temps even a problem?
Looking for data and ideas from people that know about the internals of the 9A1 that goes into a Carrera.
TIA
This past weekend I was at WGI. It was 93 degrees (low humidity) and I saw 261 degrees (oil temp). Last year in August at Summit Point (temp in the high 90's) I saw 278 degrees. This was on the MFD that provides a numerical value and a position on a bar graph. While these values seem high I noticed that the indicator was still quite a way from maximum, I'm guessing the maximum is around 300 degrees.
I do not have a center radiator yet (being installed in July) and was wondering what others are finding. Discussing this with folks in the paddock we all agreed that we didn't know that much about the internals of the 9A1 engine and that newer cars purposely run warmer for more efficient emissions. This then leads to the question, are these temps even a problem?
Looking for data and ideas from people that know about the internals of the 9A1 that goes into a Carrera.
TIA
06-18-2018, 08:49 PM
#3
I was at the Glen last week, in my 991.1 GT3
Air temps second day were low to mid 80's (first day was cooler and overcast, so not good data source)
Water temps max around 200-210
Oil Temps max about 210-215
these were usually 25-35 minute sessions, running 2:07-2:09's with a few 2:04-2:05's thrown in, so not dawdling.
In my GT4, at WGI two weeks ago:
Air temps more like 90
Water temps max 220
Oil temps max 220-225
those were only 20-25 minute sessions, running about the same times as above on Pirelli DH's
Porsche GT cars really have EXCELLENT cooling.....my 2011 ZR1 would get temps way above 250's-270's for sessions like those in similar weather..
hope that helps?!
Air temps second day were low to mid 80's (first day was cooler and overcast, so not good data source)
Water temps max around 200-210
Oil Temps max about 210-215
these were usually 25-35 minute sessions, running 2:07-2:09's with a few 2:04-2:05's thrown in, so not dawdling.
In my GT4, at WGI two weeks ago:
Air temps more like 90
Water temps max 220
Oil temps max 220-225
those were only 20-25 minute sessions, running about the same times as above on Pirelli DH's
Porsche GT cars really have EXCELLENT cooling.....my 2011 ZR1 would get temps way above 250's-270's for sessions like those in similar weather..
hope that helps?!
06-18-2018, 08:59 PM
#5
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I’d trust a logger long before I’d trust the dash...
06-19-2018, 12:38 AM
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Unfortunately the factory dash displays water temp of 194F even when actual data is well above that.
The factory oil temp display is usually pretty close to actual data. 270+F is not uncommon on hot track days on stock 9A1 engine without center rad and bigger oil cooler. The factory "oil cooler" is really a liquid-to-liquid heat exchanger that conducts/spreads some oil temp on to the coolant. Thus having the 3rd radiator will help reduce oil temp by making the coolant system more efficient.
IMO, when the oil temp exceeds 275F I'd change the motor oil right after the event. Many car owners don't it and keep on running so may be I am just overly concerned because I've seen the worst that could happen.
The factory oil temp display is usually pretty close to actual data. 270+F is not uncommon on hot track days on stock 9A1 engine without center rad and bigger oil cooler. The factory "oil cooler" is really a liquid-to-liquid heat exchanger that conducts/spreads some oil temp on to the coolant. Thus having the 3rd radiator will help reduce oil temp by making the coolant system more efficient.
IMO, when the oil temp exceeds 275F I'd change the motor oil right after the event. Many car owners don't it and keep on running so may be I am just overly concerned because I've seen the worst that could happen.
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2023 Porsche Sprint Challenge 992 Cup Am Champion
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TPC Racing stats:
2023 Porsche Sprint Challenge 992 Cup Am Champion
2023 Porsche Sprint Challenge GT4 Pro-Am Team Champion
2022 Porsche Sprint Challenge 992 Cup & 991 Cup Champion
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06-19-2018, 12:42 AM
#8
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Also higher speed tracks(more air flow to rads) and not getting stuck directly behind slower cars(cleaner air flow to rads) usually help reduce oil temp.
06-19-2018, 07:45 AM
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06-19-2018, 08:22 AM
#10
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Thread Starter
Unfortunately the factory dash displays water temp of 194F even when actual data is well above that.
The factory oil temp display is usually pretty close to actual data. 270+F is not uncommon on hot track days on stock 9A1 engine without center rad and bigger oil cooler. The factory "oil cooler" is really a liquid-to-liquid heat exchanger that conducts/spreads some oil temp on to the coolant. Thus having the 3rd radiator will help reduce oil temp by making the coolant system more efficient.
IMO, when the oil temp exceeds 275F I'd change the motor oil right after the event. Many car owners don't it and keep on running so may be I am just overly concerned because I've seen the worst that could happen.
The factory oil temp display is usually pretty close to actual data. 270+F is not uncommon on hot track days on stock 9A1 engine without center rad and bigger oil cooler. The factory "oil cooler" is really a liquid-to-liquid heat exchanger that conducts/spreads some oil temp on to the coolant. Thus having the 3rd radiator will help reduce oil temp by making the coolant system more efficient.
IMO, when the oil temp exceeds 275F I'd change the motor oil right after the event. Many car owners don't it and keep on running so may be I am just overly concerned because I've seen the worst that could happen.
BTW - Where have you been? Haven't seen you at the track lately but I have seen you selling random car parts. Working on a new car?
06-19-2018, 10:29 AM
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I signed up for P-fest in August. See you there!
06-19-2018, 10:46 AM
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06-19-2018, 10:49 AM
#13
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I think about how the higher temp thins out the viscosity of the motor oil. The hotter the temp the thinner the oil gets and as the temp keeps climbing eventually the viscosity gets to a threshold of insufficient oil pressure resulting in insufficient film strength protection between metal parts. The metal parts themselves are fine to the 300+F temp but the lube isn't.
06-19-2018, 11:10 AM
#14
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Does anyone know where the oil temp is measured in the 9x1 dash gauge? Mine has seen 275F pre third radiator, and haven't tested yet with the radiator added. My Mobil 1 0w40 had reduced viscosity by 20% or so even after it cooled down, per a UOA, so I switched to 5w50.
06-19-2018, 11:13 AM
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I've studied this some on other motors, but similar temps. I went through some data with Lake Speed Jr. (Driven Oils) and engineers at a couple of other oil companies. Quality synthetic oil coming out of a motor at 300F is not hurting the oil. We ran over 30 hours on 1 oil change (14 quarts) and saw no degradation or problems. The oil analysis said we could have kept going with that oil. It's important to know where you are measuring the temp. Oil temps in a dry sump tank have a limit around 250F, but out of the motor 300F is fine. You don't want to know the temps as it comes out of the bearings!
I have a personal experience to share that doesn't amount to anything... in the past I have sent in oil samples from my personal track cars and motorbikes, I was getting reports that the oil was still good, but I changed it anyway, perhaps it was placebo effect but the engines seem to run a little bit quieter and a little bit more peppy after the oil was changed. And perhaps it might had to do with how the aged hydraulic lifters in those particular engines reacted to seasoned oil that's still considered good. Like said before I suffer from being overly concerned about almost everything.
