Following the debacle that put the Lewis Hamilton’s race victory at the Italian GP into doubt, the FIA are now working with Pirelli to regulate on a set of procedures to ensure the teams are running minimum tyres pressures.
We must remember that tyres running at lower pressures are more vulnerable to cuts from debris and kerbs. Tyres operating at lower pressures also can give incremental grip and mitigate blistering.
TJ13’s very own Mattpt55 has educated the team that given a starting tyre pressure and temperature – and change in tyre pressure resulting from a temperature alteration, is entirely predictable and the result of a mathematic algorithm. Something to do with PV=NRT… maybe.
Currently, the tyre blankets heat the tyres to a maximum temperature of 110 degress, although the operating temperature band for the various tyres during the race is mostly between 120-140 degrees.
In Monza, as the tyres were mounted on Rosberg’s car at the required temperature by Pirelli, the tyre pressures were checked and agreed to be legal.
The problem, was that Mercedes decided not to continue to warm Rosberg’s tyres and disconnected the tyre blanket power. That said, if you watch the footage back, the blankets are only removed around 30 seconds before the parade lap begins – some 2 minutes after the test.
Tyre temperature reduces – and so does the pressure.
Paul Hembery was asked during the Italian GP weekend, whether the teams were complying with Pirelli’s new tyre pressure regulations. He replied, “Mainly”.
Pirelli are of course aware that teams manipulate tyre pressure by affecting temperature and the embedded Pirelli representatives in each team are privy to tyre data telemetry from the moment the parade lap begins.
Pirelli originally wanted a Psi minimum of more than 19.5 Psi for the rear tyres in Monza, however the teams talked them down to this level.
TJ13 has learned that Pirelli requested an incremental hike in Psi to cover the team’s ability to manipulate tyre pressure, including during the ‘blanket warming period’ on the grid prior to the start of the race AND after the tyre has been pressurised and agreed by Pirelli.
This would ensure the minimum Psi required by Pirelli is adhered to, even if the tyres are unheated from the 5 minute warning.
Consequently, the FIA and Pirelli’s solution to ‘on grid tyre pressure manipulation’ is simple.
The teams must be required to keep their tyres above a certain temperature prior to the 30 seconds before the parade lap. This means the Psi Pirelli require from the tyres up to 30 seconds before the cars begin to roll can be predicted.
Either that, or the teams will be forced accept a higher Psi minimum from Pirelli to allow for potential cooling of the tyres from when they are tested/filled by Pirelli at the required temperature.
Then again – this would surely be all too simple for the FIA to regulate.
Why does anyone care what the temperatures are on the grid?
Surely, the running pressure and temperature during the race is of much more concern than the temp/pressure whilst the car is sitting there with 2 minutes to go.
If I’m Button, in a Mclaren of a few years ago, I have lots of trouble getting my temps and pressures up during the race, but if I’m a Schumacher/Rosberg in a Mercedes of a few years ago, I’m really heavy on my tyres, overheating them almost at the drop of a hat.
Neither of these things has to do with the starting temp on the grid but if the safety issue is the temp and pressure of the tyre during the race, then why aren’t maximums and minimums mandated for the race itself? (Or are they? I’ve never heard of any rules about racing temps or pressures).
I’ve never seen a tyre delaminate, explode or fail catastrophically on the starting grid, so why should I care what the starting pressures are?
The good Judge wrote, “We must remember that tyres running at lower pressures are more vulnerable to cuts from debris and kerbs.”
Pirelli hasn’t stated that there was any safety problem associated with Monza’s inflation-gate.
Pirelli did state that there are “performance” issues, per an Hembery interview. Pirelli had very high “performance” concerns at Monza. Let’s keep in mind that they’re in protracted business negotiations with Bernie. Bernie specified that Pirelli deliver 2 to 3 tire changes per race. Last year’s Monza was an easy 1 stop. This year Pirelli brought 1 step softer compounds but it was still a 1 stop race, though closer to 2 stops. If Pirelli over-inflates the tires, they get higher degradation, and push the teams over to 2 stop strategies. That was the “performance” issue.
Pirelli’s analysis of Spa never associated pressures with the unusual number of cuts and failures there. The only listed reason for the unusual quantity of tire cuts and failures was debris on the track. The only listed solution was cleaner tracks.
Given the wild variations in their pressure recommendations during the Monza weekend, (1st they said +5psi, then +4psi, then +1psi), if their recommendation was based only upon hard safety data, there wouldn’t have been so much waffling.
Pirelli’s inflation-gate at Monza was only a poor attempt at showing muscle in the paddock (fail!), and helping their own cause during negotiations with Bernie.
Pirelli’s performance this weekend at Monza was very pathetic.
And in monza they suddenly had state of the art cleaning machines trackside. Not like the brooms used in spa.
Why not just lock the tyres up after they have passed the pressure test.
There always has to be a measuring standard. Like measuring while in the interest tyre warmers., so we don’t have an old chap taking 15 mins to walk from the front to the back of the grid.
Lol. Like Charlie’s dad?
or like Charlie??
Is it normal in racing to run 1,4 bar pressure on a warm tire? With such low pressures it is no suprise to see the photos on the top of Raidillon with wobbly sidewalls. And frankly I am less surprised that they fail at times and more sensitive to debris pickup, carcass damage and cuts…..
I am puzzled. I can’t find any mention, let alone details, of these “New tyre pressure regulations for Singapore” anywhere on the FIA or Pirelli or any other websites?
The judge is all about inside information 😉
The body of the article says “the FIA are now working with Pirelli to regulate on a set of procedures to ensure the teams are running minimum tyres pressures.”
I don’t think anyone needs inside information to be able to say that. That is precisely what the stewards at Monza decreed should be done.
When they are working on it and it isn’t officially brought out you do need inside info…
Seems to me that if pressure and temperature are directly related (which, mathematically, they are) then it should be easy to draft the “minimum pressure” rule as a lb/sq in @ a given temp or its mathematical equivalent. This, as I understand it, is exactly why the Mercs were determined to NOT be illegal.
So long as any test includes both tyre temp and pressure, then legality of any tyre is easy to determine. No?
PSI and Temp are at the same time completely independent of each other AND completely dependent of each other…
it appears Pirelli wished to impose a MIN PSI at a temp approaching expected race-long tire temps. that is all fine and good and mathematically kewl.
the real issue is that the new FIA rule was, as almost always, scientifically, mathematically, operationally and legally total frigging crap. the sheer stupidity of the “new rule of the day” left the poor Stewards with little choice but to declare “no foul”…
thanx once again FIA, FOM, Bernie, CVC, Charlie and TEAM input for PROVING you are all simply NOT fit for purpose for even an amateur grade school soccer match with little technology involved!!!
I very recently stated the ridiculously stupid low pressures I sometimes ran on my ’69 Titan MK V (11psi front and 12.5psi rear). once, a super close friend (and equally close competitor) told me he feared I was gonna pop the tire off the rim on a particular corner. so, I added some pressure which helped at certain corners and hurt at others. point is: that was how WE raced 3+ decades ago. nobody told us what tires or tire pressures we needed to run, how much fuel we could use, or gave us a max RPM limit on our motor.
old school for sure, but I view this whole idiocy as slam dunk stupid…
When the volume is fixed, like in a tyre, then pressure and temperature are exactly, yes exactly, the same thing – its a consequence of the kinetic theory of gases. Other consequences are the laws of thermodynamics, entropy, the Carnot cycle and the Navier-Stokes equation, i.e. just about everything that matters if you’re interested in aerodynamic objects driven by internal combustion engines. Its incredible the FIA (and to be fair Paddy Lowe when he was initially questioned about it) simply didn’t understand that if you wander about the grid measuring pressures and temperatures the results you get will be meaningless from a regulatory point of view.
Not if the tyres were all filled at a given temperature and pressure. Take the new temperature and pressure readings, do the maths, and either someone has squeezed the valve or not.
Exactly. How hard can this be??
What is needed is to specify when and at what temperature the pressures are measured.
Then a method has to be found (such as some tamper-proof seal) to prevent the teams adding/removing gas from the tyres until the race has ended, and all the used tyres have been scrutineered to ensure that the seals were not removed intentionally at any point by the teams.
Hey Judge, it’s actually P1/T1 = P2/T2 or, rearranging, P2 = (P1/T1)(T2), where P1 and T1 are initial pressure and temperature, P2 and T2 are final pressure and temperature.
Should have added temperature is °K.
“That said, if you watch the footage back, the blankets are only removed around 30 seconds before the parade lap begins – some 2 minutes after the test.”
Uhm, were the blankets plugged in?