Oil Consumption query after taking Porsche 997S to trackday
Discussion
Hey Guys
I took my car to Mallory Park on Saturday for a car show event/trackday. I took my car onto the track for one 15 minute session during which I pushed it quite hard (but not too hard due to large number of boy racer type cars on the same session plus my unfamiliarity with the circuit.
Anyhow, by the end of the 15 minute session my engine oil temp had hit 110 - 115 degrees (water temp was 80 degrees). After the session once I got home I checked the oil level and the car had used 1 segment of oil (400ml) during the session. I topped the oil up last weekend so I know it has definitely dropped at least 1 segment. I just wanted to ask is this kind of consumption normal or excessive for such a short track session?
On a side note, my tyre performance was very poor after a few laps - the car suddenly became very wallowly and it felt like I was driving on soft squishy tyres. My rears are near the limit and the fronts have 3 mm left (Pirelli Rosso's) - is it a myth that tyres with low tread should perform better (like slicks in warm weather) or is the reality that the rubber loses its quality towards the end of the tyre's life cycle? Certainly in my case I would suggest the latter is true!
I took my car to Mallory Park on Saturday for a car show event/trackday. I took my car onto the track for one 15 minute session during which I pushed it quite hard (but not too hard due to large number of boy racer type cars on the same session plus my unfamiliarity with the circuit.
Anyhow, by the end of the 15 minute session my engine oil temp had hit 110 - 115 degrees (water temp was 80 degrees). After the session once I got home I checked the oil level and the car had used 1 segment of oil (400ml) during the session. I topped the oil up last weekend so I know it has definitely dropped at least 1 segment. I just wanted to ask is this kind of consumption normal or excessive for such a short track session?
On a side note, my tyre performance was very poor after a few laps - the car suddenly became very wallowly and it felt like I was driving on soft squishy tyres. My rears are near the limit and the fronts have 3 mm left (Pirelli Rosso's) - is it a myth that tyres with low tread should perform better (like slicks in warm weather) or is the reality that the rubber loses its quality towards the end of the tyre's life cycle? Certainly in my case I would suggest the latter is true!
knightriderx said:
On a side note, my tyre performance was very poor after a few laps - the car suddenly became very wallowly and it felt like I was driving on soft squishy tyres.
Did you do anything with the tyre pressures? How did they look after you stopped? They sound like my (rubbish) tyres when they overheated.knightriderx said:
On a side note, my tyre performance was very poor after a few laps - the car suddenly became very wallowly and it felt like I was driving on soft squishy tyres. My rears are near the limit and the fronts have 3 mm left (Pirelli Rosso's) - is it a myth that tyres with low tread should perform better (like slicks in warm weather) or is the reality that the rubber loses its quality towards the end of the tyre's life cycle? Certainly in my case I would suggest the latter is true!
Yes, its a complete myth - a worn road tyre is not anything like a slick, for a number of reasons, but primarily the number of heat cycles the tyre has gone through means the rubber which is left is way past its bestTheInternet said:
Did you do anything with the tyre pressures? How did they look after you stopped? They sound like my (rubbish) tyres when they overheated.
I had the tyre pressures set at 37 front and 41 rears and as I only went out for 1 session I did noyt adjust them - were my pressures OK?After I stopped the near side tyres had taken quite a beating and had loads of rubber 'blots' built up on them and all 4 tyres looked quite rough and scrubbed.
What oil do you use out of interest? It's not uncommon for an engine to use a bit after being thrashed on track, have you checked under the car once it's cooled down for leaks, like the morning after?
Those tyre pressures sound very high, I run 29 and 30 fr/rear and drop them by 6 or 7 psi if I go on track as they will heat up quickly. You will find that a wide flat tyre will 'bow' in the middle if over inflated. Tread wearing in the middle is a sign. (Tread wear on the edges a sign of underinflated tyres, which you knew, of course)
After I stopped the near side tyres had taken quite a beating and had loads of rubber 'blots' built up on them and all 4 tyres looked quite rough and scrubbed.
Those tyre pressures sound very high, I run 29 and 30 fr/rear and drop them by 6 or 7 psi if I go on track as they will heat up quickly. You will find that a wide flat tyre will 'bow' in the middle if over inflated. Tread wearing in the middle is a sign. (Tread wear on the edges a sign of underinflated tyres, which you knew, of course)
knightriderx said:
TheInternet said:
Did you do anything with the tyre pressures? How did they look after you stopped? They sound like my (rubbish) tyres when they overheated.
I had the tyre pressures set at 37 front and 41 rears and as I only went out for 1 session I did noyt adjust them - were my pressures OK?After I stopped the near side tyres had taken quite a beating and had loads of rubber 'blots' built up on them and all 4 tyres looked quite rough and scrubbed.
Edited by Oilchange on Sunday 22 May 23:06
Contrary to some of the advice on this thread, I wouldn't immediately drop the tyre pressures. Road tyres often don't have stiff enough sidewalls to support the pressures being dropped. If you drop them, you can end up with a situation where the sidewalls are folding like this:
You may find you need to increase pressures from standard recommendation in order to maintain the sidewalls. Unfortunately there's no hard and fast rule, some road tyres you can drop the pressure, but some you need to increase. You'll have to experiment to be sure, but it could be the pressures you have just now are as good as it gets and thats as much grip as you'll get.
You may find you need to increase pressures from standard recommendation in order to maintain the sidewalls. Unfortunately there's no hard and fast rule, some road tyres you can drop the pressure, but some you need to increase. You'll have to experiment to be sure, but it could be the pressures you have just now are as good as it gets and thats as much grip as you'll get.
...particularly if you drive like a muppet straight out of the paddock.
Generally modern tyres have harder sidewalls to support the heavier modern motors.
Ie Golf 1 to Golf VII
Pressures need to be set a couple of psi over std road settings (but this depends on feel), and then bled off at the end of your session...as you speed and confidence grows...maintaining the original figure.
As Mr Noble says, tyres over inflate during the day by around 7psi
He must have been going some to hit 10!
Remember to reinflate at the end of the day or you will be driving with 7ish psi down!
A
Generally modern tyres have harder sidewalls to support the heavier modern motors.
Ie Golf 1 to Golf VII
Pressures need to be set a couple of psi over std road settings (but this depends on feel), and then bled off at the end of your session...as you speed and confidence grows...maintaining the original figure.
As Mr Noble says, tyres over inflate during the day by around 7psi
He must have been going some to hit 10!
Remember to reinflate at the end of the day or you will be driving with 7ish psi down!
A
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