Turkish Grand Prix 2008

[Ciro Pabón]

You ask me what's the recipe for Hamilton's tyre fault. When you are heating a tyre the recipe is simple:

- lower the pressure (this is what you do "at first sight")
- diminish ackerman to diminish differential slip of tyres
- diminish toe angle of wheel

http://www.msquaredkarting.com/download ... manual.pdf

You cannot lower pressure too much: this leads to flexing of the walls.

I quote http://timesonline.typepad.com/formula_one/

It seems the problem with Lewis's front-right tyre going through Turn 8 was a failure in the inside sidewall area of the tyre as it experienced extreme lateral load for a period of around 6 seconds on a cornering sequence with a sustained G-Force of around 4.5.

The causes quoted:

Lewis's overall car set-up and level of downforce/wing angle
His performance over the entire lap at Istanbul
His preferred angle of entry going into the sequence
His speed of entry
His mid-corner speed(Kimi set the fastest apex speed at 226.6km/h)
His throttle inputs
His steering inputs
The slip angle of the tyres(the difference between the trajectory of the wheel and the trajectory of the tyre itself)
The toe angles of the tyres(pointing in or out)

There is no mention of impromper manufacturing of the tyre, so I'm still curious about where did you read that.

[John Stitch]

It would appear that Bridgestone have not built an adequate margin of strength into the tyre.

I also noted that one commentator said that they had miscalculated with regard to compound and should have bought tyres of a softer grade due to the unuseually low temperatures.

So, I suspect, whilst they didn't help Mclaren with the construction of the tyre they did help them with regard to compound.

[WhiteBlue]

Ciro, thanks for the Gorman article. Please consider that Gorman did not know that Heikki was also restricted to a 21 lap strategy. Read Martin Witmarshs debrief on Pittpass from which I quoted higher above. There is also a link to read the full text.

The McLaren wasn't considered safe for more than a third of the race distance. It really was the cars high frontend grip in the high g-force turn 8 situation. Heikki wasn't allowed on a one stopper after his accident and tyre change. They had the same safety concerns about his car as well.

Withmarsh also mentioned setup optimization which was contrary to what you posted. He said they had to increase the pressure. You said to decrease the pressure.

[checkered]

I see WhiteBlue's reasoning as

valid insofar as the type of failure is concerned. No F1 racing tyre should provide more grip - under any setup or controlled circumstances - than the structural integrity of the sidewall can withstand. There's no reasonable margin of error to a sudden and uncontrollable structural failure due to a single force or a single condition that can be exerted on a tyre by driving a F1 car on a F1 track. That, I gather, was what FIA's tender was getting at.

It is straightforward, really: A driver is free and able to protect or destroy the tread as he pleases, but should not be held responsible for the supporting structure. Not any more than that of a wing, an A-arm or a connecting rod. It is immaterial how many drivers were at risk this time around, for none should have been. Bridgestone misjudged the margins, only just, but nonetheless. Obviously there are other considerations since they cut it so close to the requirements of (what is said to be) the most demanding curve of the season and it is for them to know what they have to accommodate through the season. It's not like slapping on a couple of layers of ply equals "mission accomplished"; a force cannot be independently compensated for without considering every momenta affected by the change. And in that equation I guess the teams are also partly responsible for what they have instructed Bridgestone to deliver.

Funnily enough we wouldn't even know this had Lewis not spilled the beans in the press conference ... he was so happy to have exceeded the team's projections (was it 5th to 7th?) that there was no containing him I guess. Overall, since Bridgestone was onto the problem, it wasn't that dramatic. And expanding on WhiteBlue's "99% safety margin" statement, adding up what the FIA classifies as "turns" (Valencia and Singapore are n/a) through this season, the total comes to 245. So if turn 8 of the Istanbul remains the only example of such a problem emerging, Bridgestone's success rate is ~99,6%. Given that only one team was recognised as having the problem, the projected success rate goes up to ~99,96%.

Presuming that the tyres will now be made foolproof in this regard (at least I hope they are, if possible), the only potential for controversy remains in the championships. Should either Lewis or McLaren lose both, or either one, by a margin of two points or less, I can see a somewhat heated debate emerging over this yet again.

[Ray]

I'm done with this topic. I find it hard to believe that ONE SINGLE SOLITARY PERSON has a tire issue and all of a sudden it's a safety problem for the other 21 racers and cars. WhiteBlue, you exhibit no common sense or rational reasoning. Of course McLaren are going to say anything they can to squarely lay blame on Bridgestone. You're insistence on a safety problem over common sense is quite honestly infuriating. I quit. I will not give anyone the pleasure of responding to any ludicrous accusations in response to any of my posts on here, or the bullshit accusations directed at Bridgestone. Congrats, most of you have gone down a notch.

[WhiteBlue]

....
Presuming that the tyres will now be made foolproof in this regard (at least I hope they are, if possible), the only potential for controversy remains in the championships. Should either Lewis or McLaren lose both, or either one, by a margin of two points or less, I can see a somewhat heated debate emerging over this yet again.

thanks for mentioning that checkered! people probably know that I'm not partisan for McLaren. It should be clear that my opinion is mainly driven by concern for the drivers safety. Hamilton said it was pretty uncomfortable to drive that way and he checked the tyre on the exit of turn 8 every one of the 68 laps.

[Ciro Pabón]

On the source:

Well, I say this is just an exalted british journalist talking about McLaren. There is no need to fight over a Pitpass article, that seems written to encourage fighting. I still wait for the proof of bad design of the tyre, which I haven't seen.

There is no way to overcome the fact that it was one driver who had problems. All high speed curves degrade tyres. If you take it in such a way that you degrade them, you change your approach. Of course, you can always find the odd guy that claims that it's not his fault, that it's the fault of the equipment, but most of the time all he gets are sorry looks from the mechanics...

About Kovalainen not being able to do one stop

That is the reason why we have pitstops in high speed tracks, just ask any NASCAR fan: half or more of the times you stop for tyres, not for gas. You stop mainly for gas only in F1, where you have a lot of slow speed tracks, more devoted to acceleration and braking. The fact that the new safety measures have allowed track designers to resurrect high speed curves has taken the mechanics and drivers to another level, let's hope they understand it.

Many people that watch only F1 does not understand the courage and ballsiness of NASCAR drivers in that respect. McLaren comments about the tyres would be seen as pansy in that environment, where I've seen, after the race, tyres taken truly to the limit.

About the pressure

I guess they had to increase pressure trying to stiffen the walls, because the graining was not in the surface. In that case, the main suspect is the chassis, or suspension arrangement, which has not enough stiffness. When you increase the pressure there is no way to avoid tyre overheating, unless you're already at extremely low pressure, trying to cool the tyre.

Low pressure can be taken down just so far, you cannot hope to diminish pressure forever with the same results of cooling. Once you are very low, the tyre does not put all the rubber on the track and overheats again.

I think it's easy to understand the fact that setting up a car consists of tweaking parameters to try to find the best "solution". If the "recipe" says "decrease pressure" it would be mad to conclude that you can decrease it as much as you want, there is a limit. If not, the coolest tyres would be tyres with no air at all.

Where a car takes a curve, part of the peak loads are adsorbed by the "looseness" of the chassis. That helps up to a point, but you cannot exaggerate. You cannot build a chassis that "rests" entirely on the tyres.

My conclusion

Complaining about the manufacturer seems cheap, unless you can prove that it was a design failure.

All components are designed to the limit. If a driver breaks consistently a rod and only he does it, then his team has the burden of proof when bad design is claimed. Probably the team is not using the part properly. In this case, given the reasons alleged for failure, all you can conclude is that Hamilton deserves a new nickname: Lead Foot.

He's in the position of having to prove the opposite, claiming he deserves specially constructed equipment demands "extraordinary proof".

It's funny to complain about tyre degradation in high speed curves. This is the place where it happens, by heavens sake. The first conclusion is that the chassis is not up to the task.

The article mentioned sounds as if McLaren demanded a softer tyre for their chassis. That's certainly a little arrogant, just in the style of the source.

[WhiteBlue]

.....About Kovalainen not being able to do one stop

That is the reason why we have pitstops in high speed tracks, just ask any NASCAR fan: half or more of the times you stop for tyres, not for gas. You stop mainly for gas only in F1, where you have a lot of slow speed tracks, more devoted to acceleration and braking. The fact that the new safety measures have allowed track designers to resurrect high speed curves has taken the mechanics and drivers to another level, let's hope they understand it.

Many people that watch only F1 does not understand the courage and ballsiness of NASCAR drivers in that respect. McLaren comments about the tyres would be seen as pansy in that environment, where I've seen, after the race, tyres taken truly to the limit...


.... It's funny to complain about tyre degradation in high speed curves. This is the place where it happens, by heavens sake. The first conclusion is that the chassis is not up to the task....

I believe that you have not understood what Witmarsh was talking about. There was no issue of tyre wear or degradation for Heikki or for Hamilton. Heikki was kept from doing a 1 stopper because Bridgestone issued a 21 lap limit on both McLaren cars after they found side wall delamination. Side walls don't deteriorate due to wear. they are supposed to remain completely intact and untouched by normal racing. when they are a concern you always have a design or manufacturing fault or accident damage.



another famous side wall failure under high loads (2005 Ralf Schumacher Indianapolis)

Every tyre man or race engineer has this picture burned into his mind. I think that Bridgestone got really scared when they found side wall delamination on Friday and pulled the emergency brake on McLaren.

[Ciro Pabón]

Exactly my point. Schumacher had a failure in a high speed curve. This happens in NASCAR all the time. The walls wear because of flexing under low pressure, I've told that already. This could mean they were trying to low the heat, but trying to conserve the thread they ruined the walls. Duh.

Tyre failure has always existed and always will, unless they develop wear proof tyres.

In the fifies, when Pirelli dominated over Dunlop, Continental and Englebert, there was the retirement of Englebert when Alfonso de Portago, his co-driver and 10 spectators died in the Mille Miglia.

Then, when Dunlop enjoyed a virtual domination during the 60s, I remember Richie Ginther flying over the trees at Monza old banked track because of tyre failure.

In the seventies it's unforgettable Mark Donohue accident. His widow won a lawsuit over Goodyear, many years after his death.

In the eighties I remember Jacques Villeneuve crashing really hard at Imola and Jean Pierre Jabouille losing at Kyalami. Michelin had the accident at Adelaide that robbed Mansell of the championship. Piquet had a huge crash at Imola and Senna was lucky in Hockenheim after a clear tyre failure.

When Goodyear retired at the end of the nineties there were another accident by Hakkinen (maybe two) and another by Coulthard. It was diagnosed as too much grip developed by the chassis.

In the 2000's we had, besides Schumacher accident the ones that Michael Schumacher and Olivier Panis had while testing at Monza.

At NASCAR, the cup had one tyre supplier for years. At the end of the 80's Hoosier step in and this was a particular bad year with maybe a dozen of injured drivers during one year. After Bill Elliot and Dale Earnhardt had serious crashes at Daytona (? not sure) Hoosier retired. At that event Goodyear retired their cars. In the following years (1995 maybe) Rodney Orr and Bonnet died because of tyre failures, also at Daytona, I think.

Are there any conclusions of all this?

Yes, take care of your tyres, use a setup that gives you margin. It serves nothing to have one lap stints that are really fast to have your tyres degrade 2 tenths per lap. You have to build a car that is "smooooth" not a car that grips like a fly to the celing because it superheats its tyres. It's entirely a responsability for the team.

About the soft/hard tyres, Ferrari had the inverse effect of McLaren, so I cannot buy the argument that they had a problem with them caused by Bridgestone.

Every car is different. The make-up that looks fine on your wife may not be as good on your daughter. Most of the time it's not the fault of the make-up manufacturer but of the guy that put the make-up on them.

Finally, McLaren is full of excuses. Last year they claimed it was Alonso's fault, in the name of all that is decent, because he did not share his setup with Lead-wis Hamilton. C'mon. This year they need a special tyre. They may have some reason, I cannot discard that, but they whine too much and prompt others to do the same. Ehem.

[WhiteBlue]

It may be ok for American oval racing with banked corners, but in my view side wall failures are not acceptable in F1 racing. I know that the FIA took the same view. In 2005 Mosley wrote to Dupasquier of Michelin and inquired about such failures and what was done to stop them.




Those failures that I know off were usually due to damage from debris, curbs or abused wear.

Eventually we are getting to the bottom of this. So you basically say that in addition to increasing pressure and going less aggressive through the corner McLaren should have taken downforce away, because that would have reduced the overload.

I reckon we can close the debate. We have a fundamentally different opinion what is acceptable in terms of side wall strengh in F1.

[checkered]

Exactly my point. Schumacher had a failure in a high speed curve. This happens in NASCAR all the time. The walls wear because of flexing under low pressure, I've told that already. This could mean they were trying to low the heat, but trying to conserve the thread they ruined the walls. Duh.

It may be ok for American oval racing with banked corners, but in my view side wall failures are not acceptable in F1 racing.

Well, tyres' structural failures

somehow are a lesser regulatory concern in NASCAR. Ultimately the cost can be measured in lives anyhow, and the tyre philosophy is vastly different to Formula One (or any other car racing series for that matter). On heavily banked ovals the drivers can choose the direction of the stress to the tyre by their driving line, a properly heated tyre with higher pressure being able to withstand higher asymmetric forces. There seems to be more complacency about the manageability of the structure as a whole, not just the tread. Perhaps this is found acceptable because there is a "tool" to manage the structure too, but it certainly isn't something F1 teams can readily relate to. Nor should they.

This reminds me of a relatively recent Gordon Kirby article, where open wheel rookies' performances in NASCAR were discussed. In fact, the tyres are so narrow that cars tend to squirm under the loads and part of controlling (apart from driver skill) this includes "sideforce" i.e. aerodynamic elements that provide directional stability. A direct quote from "Dario Franchitti and Patrick Carpentier discuss their early NASCAR lessons"; the quote also illustrates why a NASCAR comparison is perhaps the least pertinent of all four wheel track motorsports to Formula One's tyres:

"When you first go out you need to run around the top of the track," Sadler told Carpentier. "You've got to take care of that right front tire. You can't be runnin' 'round the bottom. When you do that, you're overloadin' the right front. That's what you're doin'. You're tearin' up the right front in the first laps of the run so you're no good at the end. You've gotta bring the tires in carefully. Then you can go to the bottom."

This is one of the biggest things for an open-wheel driver to adapt to because Goodyear's tires are nothing like as effective or consistent in performance over the course of a run compared to Bridgestone/Firestone's superb tires which all Formula 1, Indy and Champ car drivers are used to. Incredibly, tire failures are common in NASCAR in the 21st century, and Goodyear's rubber may be the only racing tires extant in today's world where physical failures are accepted as normal. Coping with tires that can fail and regularly lose their performance edge dramatically is something new for Franchitti and his open-wheel colleagues.

"There are several things happening," Dario observed. "There's the weight of these cars and the tire is so bloody small that it's under a hell of a lot of stress. But it's a long time since I've driven a tire that fades. I was a Bridgestone/Firestone guy for twelve or thirteen years and I worked pretty hard developing the tires with those guys and they didn't really degrade. It was very unusual if you went to a track and the tires did degrade.

"But you're stressing the tires so much more here with the Goodyears. I'm getting used to how you have to set the car up to be loose at the start of a run and drive through that looseness so it doesn't push like a pig at the end."

As WhiteBlue stated, McLaren's was not a degradation or a wear issue, but a structural integrity issue. And not a structural integrity issue relating to tread degradation or wear either. While their car is said to produce a comparatively high amount of front downforce (and while front end L/D ratio is relatively advantageous), they certainly hadn't cranked it up to a level that jeopardised Hamilton's race pace - as evidenced by his finish position.

His setup of choice was no panic solution, outside parameters, compensating for some deficiency either, but the team did it in good faith. Only after the practice did Bridgestone come back to them to warn them off a long stint strategy and an aggressive driving line through turn eight. There's nothing suggesting that McLaren or Hamilton were operating tyres beyond Bridgestone's specifications before. I suspect even in the best of days they're pretty dependent on Bridgestone track engineers' councel when it comes to adjusting tyre parameters. If you did a poll with the teams' technical directors on whether the tyres' sidewalls' integrity is or should be a race tactical issue, the answer should be quite uniform and definite.

As to the rest of Ciro's latest message providing a historical perspective to tyre failures, it is remarkably similar in its examples, structure and historical comprehensiviness to a grandprix.com article from June 2nd, 2005: "The question of tyres and accidents". I strongly recommend reading the entire article. If only one had found that in time and provided a link, some trouble would've been spared I'm sure.

It's a thoroughly good read and examines the issue from many an angle, and despite our exhaustive exchange I found it most pertinent and useful nonetheless. Remarkably, while the grandprix.com article is generally in an uncanny agreement with Ciro's examples, their end conclusion stands in start contrast to his. Drivers shouldn't be worried about their tyres, there must not be a safety concern to the tyre that keeps them from driving to the full extent of their capabilities. This was of course highlighted in 2005 when the single tyre rule was in effect, but certainly applies to holding back to protect a structural element. Managing wear predictably is another matter altogether. The article finishes with this stark reminder:

There is much discussion needed. The conclusion that one reaches in all of this is that the people in the sport should be talking to one another about such matters. Talk is cheap. Lives are not.

And that is the culmination point of this as far as I can see. Ultimately the responsibility Bridgestone was concerned with wasn't if and how a driver could finish a race, but whether he would survive. A team and its drivers should be able to take it as a given that any margins of error do not cut that close to ultimate disasters, under any conditions. That being said, everyone reacted responsibly to the emergence of the unexpected problem and every once in a while even the best of us get caught off guard.

As stated by the grandprix.com piece, when Bridgestone was the only tyre supplier during the '90s there were a number of tyre failures nonetheless. Companies, perhaps due to the tradition and atmosphere of F1, will function pretty close to the limit even when they have a monopoly. I hope this will have Bridgestone adopt vastly larger margins for their slicks design, especially as there's no telling (accurately) what the teams can deliver within the rules. For energy recovery's sake alone, demands will remain extraordinarily high.

[WhiteBlue]

A very balanced write up by checkered. Of Course the 2005 situation was very different as the NASCAR situation is different. The control tyre contract makes it totally clear that such tyres are supposed to be suitable for all tracks and that all competitors must be treated equally. It is unthinkable that the pinnacle of motorsport cannot be supplied with a tyre that is designed with sufficient side wall integrity and then some 30-40% safety on top. I'm sure that Bridgestone have understood that. they made changes to adress the problem in 2007 and they will make the necessary adjustments for 2009. I just hope that they conduct a tyre test in Istanbul before they run the 2009 season. I understand that the aero will be much reduced and so high speed turn 8 should not be so much of a problem in 2009. but safety should always be worth the bit of extra effort.

[WhiteBlue]

On the source: Well, I say this is just an exalted british journalist talking about McLaren. There is no need to fight over a Pitpass article, that seems written to encourage fighting.

I thought that comment was strange but I did not give it much attention while we were discussing the main issue. The debrief interview isn't an article that a reporter writes to encourage fighting. It is an official communication of the McLaren team regarding incidents in a race by their CEO. As such we have to treat its content with a much higher degree of credit than the ramblings of someone who isn't informed from first hand and speaks for no one but himself. I thought I give you the full text so that you can make up your mind if it is what Ciro calls it. If the board has copyright concerns please delete it.

Post-Turkey debrief with Martin Whitmarsh
13/05/2008
Following the Turkish Grand Prix, McLaren's Martin Whitmarsh discusses how the weekend unfolded for teammates Lewis Hamilton and Heikki Kovalainen.
McLaren might not have won the Turkish Grand Prix, but it was a very positive weekend in many ways. Let's start with Lewis Hamilton's second place and his unusual three-stop strategy.

Martin Whitmarsh: "It was a decision we took on Saturday, before the third free practice session. We had concerns about tyre durability, although obviously we didn't advertise the fact. It affected Lewis in particular and we took a number of preventative measures. We increased tyre pressures on Saturday morning, but
although that addressed the problem to a degree it didn't so do sufficiently to give us the margin we needed."

What particular aspects of Istanbul Park prompted Lewis's tyre problems?

MW: "The simple answer is Turn Eight. We're very strong in high-speed corners and our chassis generates a lot of front-end grip. Last year we had a chunking problem with the tyre, this time it was sidewall delamination.
We're generating high vertical loads through those corners and that's the problem. Bridgestone acknowledged as much, but they are good, strong partners and we'll continue to work with them to make sure we don't have any recurrence."
Heikki was theoretically able to run a two-stop strategy.

Are there marked differences between his driving style and Lewis's?

MW: "They run a slightly different set-up that puts a little bit more load on Lewis's front tyres. He was reasonably aggressive through Turn Eight and very quick, but he changed his style and racing line on Saturday. But on a circuit like this, once you see there's a tyre concern you have to put safety first. We took a
decision and it was the right thing to do with the information we had available at the time."

Lewis claims this was the finest performance of his F1 career to date…

MW: "My memory's so short that I don't want to draw comparisons! It was his finest race this year and he did it with the odds stacked against him. He was just flat out and really took the race to Ferrari."

With a better qualifying lap, Lewis might have started from pole with a three-stop fuel load. Might the race have been winnable from there?

MW: "In a simple time trial, the difference between two stops and three is about five seconds over a full race distance. In reality, though, it's more than that because you don't always have the most co-operative of traffic.
It was clearly a disadvantage to three-stop, otherwise it would have been a more fashionable strategy, so it would have been difficult to win even from pole. Given the way Lewis performed, though, he might just have done it."

Given the extra fuel he was carrying, Heikki's front-row qualifying performance looks even better with the
benefit of hindsight.

MW: "I think both our drivers did a fantastic job but, from a strategic point of view, Heikki was in the strongest position to win this race. I think he would have won had he not banged wheels with Kimi Räikkönen at the start - that was just a racing incident, and nobody's fault, but the consequent puncture caused an extra stop. He was due to run longer than Felipe in the first stint and if he was close to him, which I think he could have been, he would have been able to pass him and the race would have played out differently. It's easy to say that in hindsight, but I think Heikki did a fantastic job in qualifying but was unable to exploit it in the race."

It was a particularly striking performance, given the accident he suffered in Spain a fortnight ago.

MW: "He's an extraordinary chap. I've never known him as disappointed as this, though. He really felt he could win this race - and it eluded him. I've told him that I think he's absolutely right to be disappointed, but that's a by-product of the great job he did to put himself in that position. He deserves to win races this year and he will."

Did you alter Heikki's strategy at all when he made his unscheduled stop?

MW: "We put a very small splash of fuel in, but we couldn't run long stints with either car because of our tyre concerns. We were three-stopping with Lewis and didn't have enough margin with Heikki. In that situation, we'd ordinarily have switched to a one-stop with Heikki but we couldn't do that. Our safe range going into the race was circa 20-21 laps."

Monaco is next - and that has traditionally been a happy hunting ground for the team.

MW: "It has, the team has a great history there and we are naturally looking to add to that this year. I think we'll be competitive and it's a circuit both our drivers like."

Sum up the past weekend in a single line.

MW: "The really positive thing is that we come away knowing we could have beaten Ferrari."

Sorry for the long text. I wanted to make clear that there is official communication about the tyre issue which carries a high degree of authenticity. A CEO of a 450 mil $ racing firm will be very reflected about his comments on a tyre incident. If he screws up on this he can expect bad consequences from libel to commercial disadvantages from his partner supplier.

In many ways F1 is like aircraft/airline business when it comes to safety. The racing drivers do not receive the same degree of protection that passengers get by accident investigation. on the other hand an FIA sourced safety component like an F1 tyre comes under the responsibility of the same organization that spends millions in the quest of safety and causes racing teams and race organizers to spend hundreds of millions. such a component deserves to be under the same scrutiny as a tyre on an aircraft that fails. we know that it can always happen. but it should not happen without the attempt to find out why and avoid design and manufacturing faults in the future.

[WhiteBlue]

reading the spy story again I wonder if the lack of CO2 as tyre gas had something to do with the problem

[Miguel]

reading the spy story again I wonder if the lack of CO2 as tyre gas had something to do with the problem

Well, I'm not 100% sure, but I'd say there's no way one can patent CO2. And furthermore, from what I've heard, CO2 had been previously used as a tire gas. With these factors in mind, I'd say that the FIA can't really punish McLaren if they want to use CO2 to inflate the tires.

By the way: Can you patent a chemical formula? I mean, you may patent a certain mixture of substances (like, let' say, wine) but would you be able to patent ethanol?