Track temperature
Sergio Noronha
How does track temperature influence lap times ?
Sergio
Hamish Leighton
Sergio Noronha <slu...@mail.telepac.pt> wrote in article
<5mrpb3$k...@duke.telepac.pt>...
> How does track temperature influence lap times ?
>
> Sergio
Hotter temps = more grip (more heat in tyres) = faster lap times.
Even a small change of 3-4 degrees (C) will have a noticeable effect on lap
times.
Hamish
Paul Martin
In article <01bc6e99$2c5a5360$c1cb...@hamish.sans.vuw.ac.nz>, "Hamish Leighton" <hlei...@mcs.vuw.ac.nz> wrote:
>Hotter temps = more grip (more heat in tyres) = faster lap times.
Exactly the reverse, in fact.
Sergio Noronha
Hamish Leighton wrote in article <01bc6e99$2c5a5360$c1cb...@hamish.sans.vu
w.ac.nz>...
>
>
>Sergio Noronha <slu...@mail.telepac.pt> wrote in article
><5mrpb3$k...@duke.telepac.pt>...
>> How does track temperature influence lap times ?
>>
>> Sergio
>
>
>Hotter temps = more grip (more heat in tyres) = faster lap times.
>
>Even a small change of 3-4 degrees (C) will have a noticeable effect on
lap
>times.
>
>
>Hamish
>
But very high temperatures slow cars down.
Sergio
G. Taynton
On 1 Jun 1997 14:38:20 GMT, "Hamish Leighton" <hlei...@mcs.vuw.ac.nz>
wrote:
>Hotter temps = more grip (more heat in tyres) = faster lap times.
>
>Even a small change of 3-4 degrees (C) will have a noticeable effect on lap
>times.
>
>
>Hamish
Sorry Hamish, you have this the wrong way round. The hotter the track
temperature, the slower the lap times.
Regards,
GT
Michael Capsalis
Warmer ambient air temperature also means decreased air density, and less
power output from the engine....
MC
Hamish Leighton <hlei...@mcs.vuw.ac.nz> wrote in article
<01bc6e99$2c5a5360$c1cb...@hamish.sans.vuw.ac.nz>...
>
>
> Sergio Noronha <slu...@mail.telepac.pt> wrote in article
> <5mrpb3$k...@duke.telepac.pt>...
> > How does track temperature influence lap times ?
> >
> > Sergio
>
>
Ken Fletcher
I think each compund would have an ideal track/tire surface temp.
Too low not enough stickiness = low grip
Too high ??slippery = low grip.
My uneducated guess.
Ken
Peter G. Olivola
In article <01bc6eef$359aae60$36f4...@fletcher.easyinternet.net>,
Ken Fletcher <drkenf...@easyinternet.net> wrote:
>I think each compund would have an ideal track/tire surface temp.
>
>Too low not enough stickiness = low grip
>
>Too high ??slippery = low grip.
>
>My uneducated guess.
Track surface temperatures have no significant effect on tire temperatures
except when it rains and there isn't sufficient adhesion to get slicks up to
temperature through internal friction.
--
oliv...@netcom.com (Peter Olivola)
Phil Lawson
Hamish Leighton wrote:
>
> Sergio Noronha <slu...@mail.telepac.pt> wrote in article
> <5mrpb3$k...@duke.telepac.pt>...
> > How does track temperature influence lap times ?
> >
> > Sergio
>
> Hotter temps = more grip (more heat in tyres) = faster lap times.
>
> Even a small change of 3-4 degrees (C) will have a noticeable effect on lap
> times.
>
> Hamish
in higher tyre rubber temperatures, heance better grip but also incresed
tyre wear - thus leading to a fast degredation of the tyres - ie
blistering and tyres 'going-off'.
Though not a direct result, the air temperature causes air density to
decrease - therefore the engine oxygen intake in through the air box
(above the drivers head) is reduced, leading to a decrease in engine
performance. As the engine is hotter, this also leads to a decrease in
the maximum theoretical output of the engine.
The increase in air temperature also affects the drivers as they sweat
more - sometimes interfering with their concentration and reation times.
Generally though, an increase in the air temperature (and hence the
track temperature) will lead to a drecrease in the performance of the
car
Phil
-----------------------------------------------------------------
Phil Lawson E-mail: ee5...@bath.ac.uk
Electrical and Electronic Engineering, University of Bath, UK
Homepage: http://www.bath.ac.uk/~ee5pwl/home.htm
John D. Owen
Phil Lawson wrote:
>
> Generally though, an increase in the air temperature (and hence the
> track temperature) will lead to a decrease in the performance of the
> car
>
Which is why the times set in winter testing in Spain/Portugal are
rarely matched in the races come mid-Summer, when the track temperature
is likely to be 10 degrees C or more above January temperatures.
JDO
Peter G. Olivola
In article <Pine.SUN.3.96.970602...@gsbphd5.uchicago.edu>,
Tuomo O. Vuolteenaho <ptu...@gsbphd5.uchicago.edu> wrote:
>
>According to the commentators, even after controlling for the air
>temperature, high track temperature reduces the times. The effect is
>larger for race, as the race setup is a compromise between tire wear and
>speed.
Not because of a change in the operating temperature of the tire. Tires
are, after all, only 50% of the adhesion equation. The track surface itself
has a coeficient of friction that is temperature sensitive.
--
oliv...@netcom.com (Peter Olivola)
Steve Dawkins
Hamish Leighton wrote:
> Sergio Noronha <slu...@mail.telepac.pt> wrote in article
> <5mrpb3$k...@duke.telepac.pt>...
> > How does track temperature influence lap times ?
> >
> > Sergio
>
> Hotter temps = more grip (more heat in tyres) = faster lap times.
>
> Even a small change of 3-4 degrees (C) will have a noticeable effect
> on lap
> times.
>
Well. The ITV television crew (Murray Walker, Brundle etc.) seem to
believe it's the other wayround.Would someone like to clear this up?
Hamish Leighton
Yup, I was wrong, sorry for any confusion caused. I was taking a view of
very cold temperatures which can make it difficult to get suffiecient heat
into the tyres.
Hamish
------------
hlei...@mcs.vuw.ac.nz
"if your not scared, your not trying hard enough!"
Steve Dawkins <st...@minster.york.ac.uk> wrote in article
<339BED26...@minster.york.ac.uk>...
Bob Pierpoint
In article <339BED26...@minster.york.ac.uk>, Steve Dawkins
<st...@minster.york.ac.uk> writes
>Hamish Leighton wrote:
>
>> Sergio Noronha <slu...@mail.telepac.pt> wrote in article
>> <5mrpb3$k...@duke.telepac.pt>...
>> > How does track temperature influence lap times ?
>> >
>> > Sergio
>>
>> Hotter temps = more grip (more heat in tyres) = faster lap times.
>>
>> Even a small change of 3-4 degrees (C) will have a noticeable effect
>> on lap
>> times.
>>
>Well. The ITV television crew (Murray Walker, Brundle etc.) seem to
>believe it's the other wayround.Would someone like to clear this up?
Yes, higher track temperature does mean hotter tyres, means more grip.
But higher track temp generally means higher air temperature which has
an detremental effect on the power output of the engine.
Can someone help on the exact technical description of why higher air
temp reduces power output??
Bob.
Dillon Pyron
A few factors: reduced air density, reduced thermal efficiency (cold,
compressed air makes more power), reduced heat transferance for the
engine.
--
dillon pyron
dillon...@amd.com
PADI OWSI-54909 USPSA TY-26031
It was a one-eyed, one-horned flying purple people eater.
A. Lias
Hamish Leighton wrote:
>
> Yup, I was wrong, sorry for any confusion caused. I was taking a view of
> very cold temperatures which can make it difficult to get suffiecient heat
> into the tyres.
>
> Hamish
>
> ------------
> hlei...@mcs.vuw.ac.nz
> "if your not scared, your not trying hard enough!"
>
the tyres get 'greasy' and then slippery. e.g. the qualifiers for the
Indy 500 run early AM and late PM because the temp is too hot around
midday.
AL
> Steve Dawkins <st...@minster.york.ac.uk> wrote in article
> <339BED26...@minster.york.ac.uk>...
Phil Lawson
Bob Pierpoint wrote:
>
> Yes, higher track temperature does mean hotter tyres, means more grip.
> But higher track temp generally means higher air temperature which has
> an detremental effect on the power output of the engine.
>
> Can someone help on the exact technical description of why higher air
> temp reduces power output??
>
Basically there are two major effects that reduce the output of the
engine as the air temperature increases, though I do not know which has
the largest effect!
The first effect is that warmer air will be less dense and therefore
there will be less oxygen in the air for each litre of air drawn into
the engine through the air box above the drivers head (though the
proportion of oxygen in the air will be the same!). This reduction in
oxygen means that the fuel does not burn so efficiently in the cylinders
and therefore the is a resulting drop in power output, hence a reduction
of the performance of the car.
The second effect is slightly more technical and a knowledge of
thermodynamics is required to prove this! In an energy cycle (such as
the cycle an internal combustion engine goes though), the *maximum*
possible theoretical efficency (the actual value will ALWAYS be less
than the theoretical maximum!) is determined partially by the
temperature of the fuel (oxygen + petrol etc) before combustion. The
lower then initial temperature, the higher the efficency. Hence, if the
air temperature is higher, the thermodynamics efficency of the engine
will be lower. BTW this is the principle behind intercoolers fitted on
some cars to increase power output!
If anyone knows of (or can think of!) any other reasons why engine
performance decreases with air temperature then I would be very
interested in hearing your ideas!
Markus Varsta
I
|> The second effect is slightly more technical and a knowledge of
|> thermodynamics is required to prove this! In an energy cycle (such as
|> the cycle an internal combustion engine goes though), the *maximum*
|> possible theoretical efficency (the actual value will ALWAYS be less
|> than the theoretical maximum!) is determined partially by the
|> temperature of the fuel (oxygen + petrol etc) before combustion. The
|> lower then initial temperature, the higher the efficency. Hence, if the
|> air temperature is higher, the thermodynamics efficency of the engine
|> will be lower. BTW this is the principle behind intercoolers fitted on
|> some cars to increase power output
Ave !!
Basically your interpretation about the temperature difference
is correct. The larger the temperature differential the better
the efficiency. This however is not the reason for using
intercoolers.
Intercoolers are aimed at cooling down the intake air.
If the preussure in the manifold is kept about constant
the mass flow of air increases as the air cools down, thus
more air and more oxygen is pressed into the combustion chamber.
Without the intercooler much of the turbo boost would go
into increasing the manifold pressure by heating the air, thus
part of the increase in the mass flow would be lost.
- Oho -