14 May 2013

Pirelli to make changes ahead of Montreal - The Technical Implications

Having looked at the relationship between mechanical grip and downforce of the 2013 tyres yesterday (http://somersf1.blogspot.co.uk/2013/05/pirelli-are-they-really-to-blame.html?m=1) the Italian tyre manufacturer announced today they would make changes to their tyres for Montreal. 
Armed with yesterday's article and today's announcement let's look at what that will mean for the racing going forward.

The [minimum] weight of the [car and therefore the] Tyres are mandated by the regulations which was raised in 2013 [from, 640KG's to 642KG's], to account for the construction changes Pirelli wanted to make. Any change to the construction of the Sidewall will result in a change to the tread platform too. [Amendments made to read more clearly]

Pirelli may also be inclined to change the compounds as their temperature windows may not be correctly positioned to take advantage of the new construction.

The change in Sidewall is the most significant change Pirelli can make as it not only lowers the temperature generated within the tyre, but has less impact on the aerodynamics I talked about yesterday. Less 'Tyre Squirt' means less destabilization of the exhaust plume and therefore less lateral flow into the Diffuser, creating less disruption, increasing its capacity to generate downforce.

The additional downforce means more force placed on the tyre, allowing more slip angle for less wear.

So who will benefit from the changes? Well the obvious thing to do is to bang the Red Bull drum and of course it will help them but in reality what it has the capability of doing is bringing McLaren, Williams and Sauber back into play. 

I feel for Hamilton and Rosberg as whilst their chief Lauda has been one of the ones complaining, I doubt he realizes these changes will be to their disadvantage. If anyone has benefited this season from the tyres construction it is Mercedes, able to leverage extra mechanical grip by virtue of their 'Coanda' exhaust being less effective than others. (Let's remember they didn't start using 'Coanda' until after the engine mapping restrictions came in at Germany last year.  This means their maps this year are less than optimal for their 'Coanda' setup) 
Quite brilliant in qualifying and toward the end of the race the Mercedes clearly has great pace but for me is obviously sensitive to ride height and Diffuser performance.  The change of construction will benefit them in the fact it will give them a wider operating window but it will also take away their qualifying pace.

Anyone fearing a slide in form from Lotus shouldn't, they have a way of getting their car in the middle of the tyres operating window, this allows them to make the best of both compounds being used that race and so now they may just sit a little lower in the temperature range. This of course won't be a problem as relative to their competitors they will still be kind on their tyres. Whilst others run 3 stops they may still be able to do 2...

Ferrari finished last season right on the heels of Red Bull and have understood the 2013 tyres and the strategy required of them more so than some of their rivals, making a switch back to their 2012 arrangement shouldn't cause them too many issues.

I've already mentioned Red Bull but as a team that seem to be able to generate more rear downforce through virtue of exhaust manipulation than anyone else they have to be in the hot seat to make gains.

As a visceral way of understanding these implications expect to see teams adjusting the Vertical floor Strakes and 'Tyre Squirt' slots ahead of the rear wheels. We will also see teams making refinements to their 'Coanda' setups to repurpose the exhaust plumes role between the rear tyre and Diffusers edge. Rear Brake drums and Rear Wing Endplate Strakes are another area that will need adjusting as they are critical to the way the Diffuser makes downforce.

This all leads to more work for me telling you about these modifications so I look forward to it but as I pointed out yesterday I think the whole situation is a knee jerk reaction and will now tighten the pack once more. Just how fair is that though when some have done their homework at the start of the season and now we have got to the test some of the teams go into the exam with the answers.

11 comments:

  1. The 2012 tyres were characterised as having a narrow operating window. Pirelli's stated aim was to increase this for 2013. Don't know if they've been successful, but how does the change to 2012 construction widen the operating window? Doesn't make sense.

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    1. The 2012 tyres didn't necessarily have a narrow operating window, the problem with them was their construction made them wear on the shoulders. This lead to the tyre still having grip just not in an area that was accessible to the driver. Teams exacerbated this by forcing the tyre to lean more and trying to use camber thrust like you would in say Moto GP.

      Pirelli won't switch directly to 2012's construction but strengthen the Sidewall whilst retaining the rigidness of the tread platform...

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    2. Will Pirelli stick to 2013 compound while using 2012 construction?

      If yes, would the tyre wear rate be the same but the tyres would last a little longer?

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    3. I'm awaiting the official details of the new tyres but there could be any number of ways they could be altered.

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  2. Can you tell, going from 2012 to 2013 tyres. Which teams were supposed to benefit from the change ? Was that change made in mind with helping some teams and hindering other? Do you think that tyre task is to benefit some teams and hinder others? Should be tyres indifferent to cars? It is control tyre ,right? Shouldn't bring any advantages.
    For me reason for the change to new tyre is mainly PR and safety. Pirelli doesn't want their tyres to delaminate. And they take measures for building this new tyres long time ago. They can't do it for less than month now. So ,it is not knee jerk reaction. So, the problem is that Pirelli can't build tyre good enough for racing. Because steel in 2013 tyre structure heat more and they need to change structure now. All this is Pirelli problem. And lets not cry for those who did their homework according to you. And Pirelli try to put the blame on somebody else, thus hiding the real problem. Bad tyres.
    Bernie tell them - tyres are wrong, not what we wanted from Pirelli.

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    1. Pirelli's tyres have no steel in them... Race tyres tend not to be built with that limitation. As for the safety aspect the 2013 tyres have been delaminating due to debris, this however shouldn't be seen as a problem as more a better way of dealing with the situation. In the past debris would cause the tyre to deflate causing damage to the car and inevitably result in the driver retiring. The early 2013 construction allowed the tyre to deflate but by virtue of it's rigid tread platform allow the driver to make it back to the pits (albeit not in Hamilton's case due to the suspension failing) with or without the top tread laminate.

      The racing we saw between Perez and Button would have resulted in a rear puncture for Button in 2012 as the Endplate would have had an easier job of permeating the tread patterns surface. This is the problem, what you take with one hand, you lose in the other....

      The change of tyre from Montreal onwards will impact EVERY team, not only at the track but away from it as the designers once again have to hit the reset button and almost throw away everything they had planned for the rest of this season. It WILL benefit some teams more than others and I'm not into conspiracy theories about who leveraged the changes but it's clear to me that some teams won't be happy about these changes and it will change the pecking order.

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  3. Will the teams have sufficient information, in advance, to start to predict the performance of the tyres and set-up on simulators, etc. before Montreal. Otherwise will they have to try and find out in FP, QP, and the race ?!

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    1. The teams should be getting the construction data from Pirelli today in order to effect any changes ahead of Canada. I would assume the scale model wind tunnel tyres will also be made available to them asap too.

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  4. herowassenna18 May 2013 02:05

    Hi Matt, I've read your work here and thejudge13 blogs. Quick question, was tweeted this by scarbs, whats your thoughts?

    FIA declares Formula 1 tyre tweaks can only be for safety
    By Jonathan Noble Friday, May 17th 2013, 19:46 GMT

    Spanish GP 2013Pirelli's planned mid-season Formula 1 tyre tweaks are set to be much smaller than originally anticipated after the FIA ruled that changes will only be allowed on safety grounds.

    Sources have revealed that the governing body has told Pirelli that it is happy to accept - and is indeed keen for - alterations necessary to prevent a repeat of the rear tyre delaminations that have struck at the last few events.

    But, in a blow to outfits like Red Bull hoping further tweaks would help them overcome tyre difficulties they have faced, the FIA has made it clear it will not tolerate further changes aimed at reducing the number of pitstops or decreasing degradation.

    Sorting out the issue must also not lead to a change of specification back to the 2012 tyres, as some had suggested could happen.

    Instead, Pirelli has been instructed to solve the matter by modifying the current specification of tyres. It is now close to finalising tweaks in this direction.

    The FIA is basing its stance on Article 12.6.3 of the technical regulations, which has also been cited by teams to Pirelli amid questions about the legality of a bid to change the specification.

    The rule states: "Tyre specifications will be determined by the FIA no later than 1 September of the previous season. Once determined in this way, the specification of the tyres will not be changed during the championship season without the agreement of all competing teams."

    Although another clause in the regulations says that changes can be introduced if the tyres are deemed by the tyre supplier and technical delegate as 'technically unsuitable', the FIA does not believe that the current high degrading nature of the tyres that sometimes requires four stop races falls under that banner.

    An FIA source told AUTOSPORT: "Discussions between the FIA and Pirelli are ongoing regarding the tyre failures and making changes to prevent them happening again. These talks do not involve the subject of degradation or the number of pitstops."

    CHANGES NOW SET TO BE MINOR

    Paul HemberyPirelli has not yet settled on what changes it is making to the tyres, but its motorsport director Paul Hembery suggested on Friday that revisions were likely to be small.

    "Let's wait and see exactly what changes we will be making, but we are doing everything we can to minimise what will be different," he told AUTOSPORT.

    The stance from the FIA, allied to Hembery's suggestion, looks likely to be good news for outfits like Lotus, Ferrari and Force India that had been concerned a wholesale change of tyres could hurt the advantage they currently have.

    Lotus boss Eric Boullier aired his frustration earlier this week at Pirelli planning mid-season changes, but expressed his hope that any tweaks would be minor.

    "That there are changes to come can be seen as somewhat frustrating, and I hope they are not too extreme," he said. "It's clear that Pirelli have found themselves in a difficult situation and under pressure from different quarters."

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    1. Hi

      Yea, I tweeted just before Craig about it too and continued to interact with people on the subject over on twitter as I was away from my laptop so couldn't blog about it. Seems the FIA have seen sense, but how far will Pirelli have to adjust the construction of the tyre in order to stop delaminations? I'm guessing they will have to add some rigidity to the Sidewall and reduce some of the tread platform stiffness which will of course have an aero effect. I'm not wholly bothered by the delam's anyway and feel they may even be safer than having the whole tyre crumple.... At least so far it has given the driver the opportunity to either park safely or get back to the pits (except Hamilton). Had the 2012 construction been in use during Barcelona, Alonso wouldn't have made it back to the pits without first destroying at least the floor of the car...

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  5. There is no aero optimization without first optimizing mechanical/chemical grip.

    There is a reason why F1 cars employ carbon fibre in the chassis, pushrods, wishbones, etc and why they strive for frictionless bell cranks and other joints. With the loads being placed on these components, there can be no change in their flexibility at all. Can you imagine a chassis or pushrod that begins to flex half way through a race due to the increased heat associated with racing! The setup of your dampers, anti-roll bars, third springs, inerters, etc. becomes null and void. Certain variables need to be a CONSTANT.

    One important piece is missing from the previous description of mechanical setup. The tires!
    Ask any competent participant in karting or FormulaFord, i.e. non-aero, who has been involved in a change of tire manufacturers from one season to the next. In high speed, top gear corners, it is the sidewalls that you notice immediately! In higher formula this sidewall effect is all quantifiable and measurable.(strain gauges, potentiometers, IR sensors, etc.)

    Just as mechanical setup is useless when structures flex and/or suspension movements get sticky, so too is aero setup when mechanical grip is not optimized. There has to be a minimum amount of sidewall stiffness to allow aero to work. Isn't if bad enough that F1 have these ridiculously large sidewalls that have always contributed far too much to mechanical setup? Aero really is the only area in F1 where creativity is rewarded. The current tires stifle any of these gains. Just as EBD and engines maps under went rules changes, it is clear who benefits and who does not. So much for optimizing centre of pressure. Do they still bring shock dynos to the race weekends or have the ability to take apart dampers? Back at base, time to assign more resources to "FRIC", etc.

    The type of racing so far this season has a place. They have a name for it, endurance racing. I'm indifferent to any changes that are made to the tires because at the end the winner will remain the same. I am not in favour of these cars being pussy footed around for 2 hours or drivers having to ask if they can defend an oncoming attack or vice versa.

    Were the last few seasons so bad? Can we not just have the same tires? Are there Pacejka values or similar rules from the FIA? It is clear that monopoly power can be abused. These problems would instantaneously vanish with the participation of another tire manufacturer. Is there any real interest in that? Not until all the cars are equal, haha!

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