How did McLaren get on terms with Red Bull in Istanbul? F1 Fanatic guest writer John Beamer takes a look at the changes to the cars in Istanbul.
On the face of it the Turkish Grand Prix should have been an easy one-two for Red Bull.
The Milton Keynes-based outfit had almost a second a lap advantage in Spain and four-tenths on the tight streets on Monaco.
So how come there was less than two-tenths between Webber, the pole man, and Hamilton, number two?
Part of the answer is that Webber wasn’t the fastest man at Istanbul Park. Had Vettel’s roll bar not broken during qualifying, causing him to lock his left-front on both his Q3 laps, the gap would have been closer to four-tenths.
Still, this is an impressive recovery from the silver team.
How did McLaren gain four-tenths?
Part of the gain was due to Red Bull having to modify its car to satisfy the FIA scrutineers. That’s right – the suspension on the RB6 was borderline illegal and had been for three races.
At the front, the upper wishbone fairing (where it attaches to the monocoque) was heavily flared. The rules state that it should be uniform width to avoid being overtly used for aerodynamic gain. Another advantage of the flared wishbone is that it allows teams to put vanes on the floor to scavenge airflow under the nose and make the front wing more efficient. This is because the floor is allowed to shadow the suspension.
Red Bull also had problems with its rear suspension too. Any wishbone that is aerofoil shaped must be at less than a 5 degree incline to the floor. The pull rod obviously exceeds that angle so Red Bull had to revert to a traditional circular structure. Engineers in the paddock estimate that these changes cost Red Bull at least two-tenths.
OK, so how did McLaren find another two-tenths?
Over the last four years McLaren has shown that it has the fastest rate of development in the paddock. In 2007 and 2008 Ferrari started off with the better car only for McLaren to out-develop the Scuderia.
In 2009 the Woking-based outfit found two seconds in five months, turning a poodle into a greyhound. And so far this year McLaren is the only team to close the gap to Red Bull.
Again in Turkey the MP4-25 sported a raft of upgrades. The front wing saw some minor tweaks. The flared rear of the endplate was more flared and had a slot to let air bleed from the high-pressure venturi section to the outer part of the endplate. This helps push the air around the tyre as the flow under the wing has greater energy.
The rear wing also received an update as the team flew in its Canada-spec wing. The main difference was a more cambered main plane but twisting down at the endplates to reduce drag. This is ideal for the low downforce Montreal track and worked a treat in Istanbul too.
The sidepod vanes were also revised. The vane now buckles inwards at the floor to direct more air away from the undercut; it also juts out a little more towards the top. In this area there is a lot of turbulent flow from the front tyres so minute changes to the pod vanes can have a positive effect on aerodynamic performance.
They are even more important now the size of bargeboards have been restricted. Under the 2008 regulations bargeboards were used to seal the floor, but they under the new regulations they are far less effective than they used to be.
Didn’t Red Bull respond?
Yes, Red Bull also updated its front wing, adding a second inlet to the endplate, serving a similar purpose to McLaren’s slot. The pod vanes were also narrower.
However, the team has spent a lot of time trying to perfect its F-duct in anticipation of Canada, which requires a low drag configuration. Each team has its own interpretation of the F-duct which is heavily compromised by the chassis design (which is homologated).
The Red Bull implentation has an intake by the airbox which leads to three ducts – one to the cockpit ?ť?Šand a Y-duct exiting between the the rear wing. When un-activated the air routes through the lower Y-duct between the rear and beam wing, where it won’t have much affect on performance.
When the driver closes the cockpit duct, more air is getting through the Y so the pressure change forces the air to take the upper route. This then exits through the sharkfin right between the main plane and flap causing the wing to sheds drag. Complicated, no?
Although the Red Bull F-duct appeared to work satisfactorily the team elected not to run partly because the drivers weren’t 100% comfortable with it.
This is a familiar theme among the teams who are trying to retrofit the device to their car. Mercedes are the latest team to publicly claim that the F-duct isn’t as effective as hoped.
For Mercedes this is partly because the team has elected to keep the razor fin on its engine cover rather than a shark fin. This means that air routes up through the rear wing endplate and then blows on to the main plane. Expect to see many constructors run the device run at Montreal come what may.
What was clear in Turkey is that in race trim there is little to choose between the Red Bulls and McLarens. However in qualifying, the lower centre of gravity of the Red Bulls, derived from the pull-rod suspension gives a significant advantage (with full fuel the CoG advantage is partly neutralised). This allows the RB6 to have better balance as well as make it easier to dial the tyres in.
And what about Ferrari?
Despite having a great car at the start of the season the Scuderia has failed to develop it quickly enough. The design team has spent a lot of time trying to perfect the F-duct, with limited success, and as a result other development has become secondary.
It was a similar picture last year when the Scuderia failed to integrate the double-diffuser as quickly as McLaren despite their vast technical resources. The team claims it has a significant upgrade in Valencia, where an extreme diffuser will be run (based on the Toyota design). Given the rate that the top two teams are developing it feel that like 2009 its going to be too little too late.
On to Canada
It’s great to have Montreal back on the calendar. Not only is it a super racing circuit which often produces races often chock-full of incidents, it also demands something different of the cars. As you’ve probably figured out from above the long straights with tight corners and hairpins suit a low drag high efficiency configuration.
Top speed is important so the Mercedes powerplant will help. Add in the F-duct and McLaren has to start as favourites. However, if Newey and team get their F-duct tuned in then we could be in for Istanbul Park II.
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