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.