Close look at Vettel's Tire before the moment...

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dans79
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Re: Close look at Vettel's Tire before the moment...

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strad wrote: SO if it comes out of the pits at a certain pressure under the blankets at a hotter temp when it cools the pressure drops?
Potentially, but i believe they have rules that govern how hot the blankets can get, and the team/Pirelli has real time data about Tire pressure.
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sgth0mas
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Re: Close look at Vettel's Tire before the moment...

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XRayF1 wrote:But how may the tire not be pressurized adequately anymore?

Two things come to my mind:
a) a slow puncture, caused by whatever reason.
b) reduced tire performance due to less rubber on the carcass

Is there a third plausible cause?

If (b), wouldn't this then actually support Pirelli's statement that Ferrari/Vettel overextended the tire wear?
Thus being their own fault?

How can a third option be correct? Pirelli stated 40 laps, ferrari did 29. Period.

Jersey Tom
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Re: Close look at Vettel's Tire before the moment...

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TAG wrote:I love how we demand that bags of rubber spinning around at 300 kph never ever fail.
Pole for Spa was a 107.2 second lap. Track is 4.35 miles, so average speed is only 146 mph / 235 kph. Obviously that becomes even slower for race pace. In road circuit racing you have left and right turns, so a tire that's heavily loaded in one corner gets relaxed the next.

Compare that to IndyCar or NASCAR. Pole speed for Michigan last year in NASCAR was 206 mph / 331 kph. Pole speed at the Indy 500 this year 227 mph / 365 kph. And with a turn every 8-20 seconds (depending on track), the right side tires never get a break. There have been NASCAR races with minimal tire wear, where some teams have run 150+ miles / 241 km on one set of left side tires. I won't even get into tire pressures - where at some tracks teams are so low that sidewalls are crinkled sitting on pit road.

Do I expect 0.00% failure rate in F1 racing? No. But in my mind - in the grand scheme of things it's just not that severe on tire durability. F1's had refueling come and go over the years, and likewise there have been years of single supplier vs. tire war. Has there ever been as much tire drama (be it wear and marbles, delaminating treads, failing carcass...) as the Pirelli years? Honest question - I can't speak to the 90's or early 00's. Don't really recall there being much drama during the Bridgestone era though.

Just some food for thought.
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ME4ME
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Re: Close look at Vettel's Tire before the moment...

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But how many G's are those type of cars doing at those type of circuits, and how frequently? (genuine question, my knowledge of these categories isn't that substantial.) By that I mean acceleration, braking and lateral force through corners. Even though, as you mention, they're doing higher speeds, I don't think they are putting as much stress on the tires as an competitive F1 car.

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dans79
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Re: Close look at Vettel's Tire before the moment...

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ME4ME wrote:But how many G's are those type of cars doing at those type of circuits, and how frequently? (genuine question, my knowledge of these categories isn't that substantial.) By that I mean acceleration, braking and lateral force through corners. Even though, as you mention, they're doing higher speeds, I don't think they are putting as much stress on the tires as an competitive F1 car.
They get to a little over 3 G's in NASCAR, but you need to keep in mind that the cars are over twice as heavy.

They can reach 5.5 G's in IndyCar, and pull them for a much longer period of time than they do in F1. A couple of years ago, they canceled a race in Texas, because drivers where passing out. They where pulling 5.5 G's for 20 seconds at a time, and that's well into fighter pilot g-suit territory.
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mertol
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Re: Close look at Vettel's Tire before the moment...

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Indycars can reach 5G-s and on ovals there is no rest for the tires - it's like 5secs turning then 5secs straight line, repeat. And not dropping under 350km/h the entire time too.
I don't think nascars are any easier on the tires either. Despite being much slower on the corners, the cars are so much heavier it might be even worse for the tires.

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mertol
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Re: Close look at Vettel's Tire before the moment...

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dans79 wrote:They where pulling 5.5 G's for 20 seconds at a time, and that's well into fighter pilot g-suit territory.
How are they getting 20 seconds at a time when the entire lap is 23 seconds?

Jersey Tom
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Re: Close look at Vettel's Tire before the moment...

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ME4ME wrote:But how many G's are those type of cars doing at those type of circuits, and how frequently? (genuine question, my knowledge of these categories isn't that substantial.) By that I mean acceleration, braking and lateral force through corners. Even though, as you mention, they're doing higher speeds, I don't think they are putting as much stress on the tires as an competitive F1 car.
I would say the loads are as high or higher, at least in NASCAR - maybe IndyCar as well. From an aero standpoint - obviously a stock car is not going to be making the same as an open wheeler at some standard reference speed, but the average on-track speeds in NASCAR and IndyCar can be substantially higher than F1. On top of that, the inertial loading from banking is no joke. A ~3500 lb car is heavy in and of itself. Going through a corner with 1.1+ G of inertial vertical acceleration from the banking throws another 4000 lb of "downforce" on top of everything.
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dans79
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Re: Close look at Vettel's Tire before the moment...

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mertol wrote:
dans79 wrote:They where pulling 5.5 G's for 20 seconds at a time, and that's well into fighter pilot g-suit territory.
How are they getting 20 seconds at a time when the entire lap is 23 seconds?
I miss read the article I used to double check if my memory was wrong. This is the full quote.
The high banks allow drivers to go full-out around the entire track, so speeds were exceeding 230 mph.

Racing at 5 Gs Instead of 3

The combination of speed and high banking subjected drivers to G forces of more than 5 for 18 of the 22 seconds it took to complete a single lap, CART officials said. A range in the 3s is generally considered as high as drivers can endure on most tracks.
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bdr529
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Re: Close look at Vettel's Tire before the moment...

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Jersey Tom wrote: Honest question - I can't speak to the 90's or early 00's. Don't really recall there being much drama during the Bridgestone era though.
I think we've become accustom to the reliability of F1 cars today, to the point that when something like two tires letting go on one weekend,is big news
I took a quick look at some stats on DNF's, regardless of the reason for the DNF, just how many in total
The top 10 drivers today in points have a total of 14 DNF's between them in 11 races, that's 1.27 DNF's per race.
In 1990 the top 10 drivers in points at the end of the year, had 34 DNF's after the first 11 races, 3.09 DNF's per race

I think we just had a lot more to talk about back then

Tommy Cookers
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Re: Close look at Vettel's Tire before the moment...

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the headline 'g' figure quoted is presumably the vector sum of the accelerometer array signals (this gives the biggest number)
the (circulatory) physiological effects are essentially driven by the g normal to the track surface (or driver centreline,really)
ie 5 g headline has the effect of maybe 3.5 - 4 g circulation-wise
and the seating position is more favourable in the car than in the plane

pre-breathing on the straight and locking the diaphragm in the corners would allow 7 g (I have done more)
and racers wouldn't notice the tunnel vision, as they have it already

EDIT
today 21 Sept ITV4 (UK) have just shown a programme called 'Goodwood cars of the future' narrated by Dario Franchitti
a driver says (of Indycar) that they get up to 4.5 g and so can't breathe in-corner due to the 'weight' on the chest
so have to breathe on the straights
..... VINDICATION !
Last edited by Tommy Cookers on 22 Sep 2015, 00:22, edited 3 times in total.

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SteveRacer
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Re: Close look at Vettel's Tire before the moment...

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Pirellis seem to be getting a bad name for all these failures. I wonder how many could be avoided with more testing. All the previous manufacturers had the luxury of unlimited testing.

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Tim.Wright
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Re: Close look at Vettel's Tire before the moment...

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So do Pirelli, they are just not interested in funding a running car + team.
Not the engineer at Force India

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turbof1
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Re: Close look at Vettel's Tire before the moment...

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Well Pirelli released a statement they have concluded their investigation - and wait for the Italian GP to release the information.

Which is very peculiar. Pirelli usually has their statements in public minutes after accidents. I have a hunch, and only a hunch so please do not take my word for it, they actually found a structural weakness which gets exposed under the right circumstances. It looks like they want the fia and the teams together to plea for a change.
#AeroFrodo

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dans79
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Re: Close look at Vettel's Tire before the moment...

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turbof1 wrote:Well Pirelli released a statement they have concluded their investigation - and wait for the Italian GP to release the information.

Which is very peculiar. Pirelli usually has their statements in public minutes after accidents. I have a hunch, and only a hunch so please do not take my word for it, they actually found a structural weakness which gets exposed under the right circumstances. It looks like they want the fia and the teams together to plea for a change.
if it is a design flaw, Pirelli is probably going to loose it's bid for a new contract.
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