Confusing Diffusers In The Spotlight Ahead Of Spanish GP

Confusing Diffusers In The Spotlight Ahead Of Spanish GP

By: Berthold Bouman, F1 Correspondent

Story Highlights

  • Ban of blown diffuser postponed by FIA
  • Teams hopeful to make the most of updates
  • Will DRS play a major role again?

Round five of the 2011 FIA (Federation Internationale de L’Automobile) Formula One World Championship will take place at the Circuit de Catalunya in Barcelona, Spain. Familiar grounds, as teams have tested here ahead of the season. The 4.655 km long track is situated 35 km north of the Catalan capital of Barcelona, and is a real drivers’ circuit, with the seemingly never ending Turn 3 which leads to the infield section of the circuit, the long back straight between Turns 9 and 10, and the narrow and twisty last section that leads to the almost one kilometer long start/finish straight. For drivers it will be difficult to find the right car setup, Turn 3 is heavy on the left front tyres and aerodynamics will play an important role, while a well balanced car is needed for the twisty sections of the circuit.

Circuit de Catalunya near Barcelona is ready for F1
Circuit de Catalunya near Barcelona is ready for F1

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It will be the home race for Ferrari driver Fernando Alonso, Toro Rosso driver Jaime Alguersuari and for the Hispania Racing Team (HRT). Local hero and double World Champion Alonso about the circuit, “All the drivers know the circuit very well and as far as setup is concerned you more or less have a baseline from all the testing data.” Asked whether his home Grand Prix adds any extra pressure he replied: “It is a unique feeling here in Barcelona for my home Grand Prix There is a huge motivation for me to do well in front of my people but also there is some extra pressure as everyone is expecting a lot from you, and you have to deliver -- but it is a nice pressure to have.”

The blown diffuser dominates the headlines

Again like the two previous seasons, they is one technical innovation that dominates the headlines in Formula One: the blown diffuser. Although not an entirely new concept, the design of the blown diffuser has now been exploited to the limit by most teams, and the FIA hinted the latest developments are not 100 per cent according to the technical regulations, and even proposed to ban the diffuser ahead of the Spanish Grand Prix. Lately teams have been experimenting with the exhaust gases that are led though the diffuser, most notably Lotus Renault, who introduced forward pointing exhaust pipes that lead the gases straight into the diffuser, which dramatically improves the amount of down force generated by the diffuser.

But the design has one weak point, the diffuser only works when there is a steady flow of exhaust gases, if a driver brakes for a corner and lets go of the throttle, he loses a lot of down force. Teams have now solved this problem by keeping the throttle at the full 100 percent under braking. The ‘off-throttle blown diffusers’ as they are called now, were introduced by Red Bull, other teams have now copied the design and during the qualification sessions for the Turkish Grand Prix teams have used it to improve the qualifying speed. Many now believe this off-throttle system is in fact the reason why Red Bull has dominated qualifying this year, and not the flexing front wing the Austrian team also uses.

The ‘off-throttle blown diffusers are still legal
The ‘off-throttle blown diffusers are still legal

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Renault has apparently pioneered the system, and that would explain why especially Red Bull and Lotus Renault benefited the most. Teams use the engine mappings, or engine ‘settings’, to assure a steady flow of gases, and the FIA believes this is not conform article 3.15 of the technical regulations, and wants to ban the off-throttle blown diffuser. It is also a waste of fuel, as it is not used to propel the car, and thus not good for achieving a greener image of the sport. Many also believe banning the device could cause a landslide in the performance of the team who currently use it.

McLaren’s Tim Goss, “All major teams are up to same tricks regards to engine mapping. If FIA's latest guidelines came in, then that would be a performance setback for us and for our major competitors. As to whether it will affect us more than our competitors, it's tough to say. At the moment we get a substantial benefit out of it.”

All major teams are up to same tricks regards to engine mapping

Tim Goss

Mercedes team principal Ross Brawn admitted it will also affect his team, “It will affect all the teams. The teams have all been developing their engine management systems to get the maximum advantage from the exhausts, and the FIA want to push us in a different direction now so there will be changes there.”

The FIA has now discussed the off-throttle blown diffuser with the teams, and have decided to postpone the immediate ban of the system, because it would result in ‘unforeseen and unintended consequences’ for some teams. The decision will now be taken after a meeting of the Formula One Technical Working Group on June 16 with FIA race director Charlie Whiting, which means teams are allowed to use it during the races in Spain, Monaco and Canada. The FIA has also made it clear the system is in fact illegal and have indicated they will not allow ‘the blowing of exhaust gases beyond 10 per cent of full throttle when drivers are braking or not accelerating’.

Teams bring updates to Catalunya

Most teams will bring the latest car updates to Barcelona, and they expect to improve their performance. Team Lotus is very optimistic about the new aero package, which consists of a new floor and a new design of the exhaust layout, which should improve the working of the diffuser. Technical Director Mike Gascoyne, “It might take us a couple of races to fully exploit it, as I think it is going to depend on the blown floor and engine strategies and some people have more experience than us with that. But we expect our update to be significant. I think we'll see a big step and I think there is more to come over the coming races.” And he is certainly optimistic about how much faster Team Lotus expects to be, “We're expecting it to be about a second, up to a second.”

McLaren team principal Martin Whitmarsh, however, is a bit more cautious about the upgrades McLaren will bring to Spain, “As we saw in Istanbul, there is always risk inherent in bringing any upgrade to the circuit -- particularly following the absence of testing. For Barcelona, we’re planning to re-introduce some of the proposed upgrades initially scheduled for introduction in Istanbul. Once again, however, they’ll only be introduced if their initial deployment on Friday proves successful.”

Mercedes GP is aiming for more consistency
Mercedes GP is aiming for more consistency

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Mercedes GP are hopeful their aerodynamic and suspension updates will contribute to more consistency. Nico Rosberg’s third place during qualifying for the Turkish Grand Prix has given the team some hope for the future. Team principal Brawn, “The last two races in Turkey and China have proved that we can be quick in certain conditions, but we need to focus on achieving that level of performance consistently over the entire race weekend. We will have an aerodynamic development package for the Spanish Grand Prix, along with refinements to our suspension package, which should help to find the consistency in the car that we are looking for.”

Ferrari is hoping to improve on the qualifying pace of the F150° Italia, as they have so far struggled during qualifying. The race pace of the car has already improved and Alonso took the first podium place of the season for Ferrari during the Turkish Grand Prix.

“We need to remember that during all the races, the pace was not too bad, everywhere. But, when you start so far behind [hinting at the qualifying result], you cannot really show completely your race pace because you have to do a good start, and try to get out of traffic so you do not destroy the tyres. That is the real issue,” Ferrari team principal Stefano Domenicali explained. “I would say we have confirmed the race pace has improved, because in Turkey we were lapping on the soft tyre faster than Webber, and the same as Vettel. On the hard tyre, Webber had one new set that he was able to use for maximum behavior. But we were very, very competitive,” the Italian added.

I would say we have confirmed the race pace has improved

Stefano Domenicali

The Marussia Virgin team has been struggling to find the right pace, and driver Timo Glock has repeatedly voiced his concern he might not be able to qualify due to the re-introduction of the 107 per cent rule. The team has been conducting straight line tests on the Idiada track least weekend and team principal John Booth is confident about the aerodynamic changes. “We head to Barcelona this week optimistic that we can continue to make another step forward. We had a positive aero test at Idiada last weekend, which we hope will help us extract more from our upgrade package at the Circuit de Catalunya,” the Briton said.

Sauber is another team that will introduce significant upgrades this weekend. Technical Director James Key expects the track will suit their car, and thinks the upgrades will be a major improvement, “We’ll have a new, quite significant aero package on the car, which will be a completely new front wing, updates to the front and rear brake ducts, new bodywork, new devices around the floor leading edge and under the chassis, and we’ll be testing the new exhaust system again.” And he optimistically added, “If it works well it should give us a good few tenths of a second improvement in lap time.”

Circuit de Catalunya, Barcelona - Spain

Circuit de Catalunya Barcelona, Spain
Circuit length 4.655 km
Direction Clockwise
Corners 16 turns (9 right and 7 left)
Longest straight 1.047 m
Total number of race laps 66
Total race distance 307.104 km
Average speed 210 km/h
Estimated top speed 306 km/h
Full throttle percentage 64% per lap
Tyre wear High
Tyre compounds Soft [Option - Yellow] - Hard [Prime - Silver]
Brake wear Medium
Downforce level Medium
Lap record Kimi Raikkonen - Ferrari - 1:21.670 (2008)
2010 Pole Position Mark Webber - Red Bull-Renault - 1m19.995
2010 Race Winner Mark Webber - Red Bull-Renault - 1h36m44.101
Speed limits in the pit lane 60 km/h during practice sessions, 100 km/h during qualifying and race
FIA Stewards Mark Blundell (GB), Paul Gutjahr (SWI) Radovan Novak (CZ)

Barcelona three-day weather forecast

Day Forecast Min Temperature Max Temperature
Friday No clouds, sunny and warm weather 12C 22C
Saturday No clouds, sunny and warm weather 13C 23C
Sunday Partly clouded, but no rain, warm weather 16C 24C

Pirelli tyre report

Pirelli has allocated the Hard (Prime) and the Soft (Option) tyres for Barcelona. However, Pirelli is still experimenting with the tyre compounds, and have decided to introduce a new hard tyre compound. The tyre has already been tested by the teams during the free practice sessions in Turkey. Pirelli is aiming for more durability of the hard tyre compound, and this also means the performance gap between the two tyre compounds will be even bigger than it was before, which could force teams to rethink their current pit stop strategy.

Pirelli Motorsport Director Paul Hembery, “We said from the start of the year that we would introduce evolutions of the tyres if we believed that they would benefit the sport and Barcelona marks the first occasion that we have done this. The new tyre -- which we have tested extensively -- reduces degradation and improves tyre wear.” And his predictions about the number of pit stops? “In Barcelona, based on the data we have seen in testing, we’re probably expecting around three pit stops per car. It takes a lot longer to enter and leave the pits in Barcelona than it did in Turkey, and this is another factor that will have a definite influence on strategy.”

DRS Setup

The FIA has announced the setup of DRS for Catalunya, the detection zone, where a driver must be within one second of the car ahead of him, is situated between Turns 14 and 16, ahead of the start/finish straight. And the activation zone, the zone where a driver is allowed to use the system, starts at the start/finish line itself, and ends just ahead of Turn 1. This means drivers cannot use the system during the entire length start/finish straight which is probably the result of the setup in Turkey, where overtaking was too easy.

Barcelona is the next proving ground for DRS

It is difficult to overtake on this circuit, it has a mix of fast corners and slow chicanes, and two long straights, and will therefore be a proving ground for the Drag Reduction System (DRS). Fans and drivers have been critical about DRS during the Turkish Grand Prix, where the system made overtaking relatively easy, and according to some, too easy.

Overtaking will be more difficult in Barcelona
Overtaking will be more difficult in Barcelona

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According to Marussia Virgin driver Glock, the trick is to get within that one second behind another car in the detection zone, “When you get within one second to the guy in front, the chances to overtake are very big. In Istanbul it was almost guaranteed. Perhaps it would have been a bit more exciting if the zone in which you can use the wing was a little smaller.”

Lewis Hamilton about the circuit, “Typically, it's been very tough to overtake at Barcelona because the best opportunity -- into the first corner -- is too fast to make a pass stick. It's always been too hard to really get alongside another driver into the corner.” And he added, “But we benefited from two great races in China and Turkey because the DRS area led directly into a heavy braking zone, meaning it was possible to get two bites of the cherry: using the slipstream and using the braking zone. In Barcelona, it's likely to be less clear-cut.”

Team Lotus driver Italian Jarno Trulli hopes DRS will create more overtaking opportunities, “There's not a lot of overtaking chances around the lap and we'll see if the DRS plays the same role in Spain that it did in Turkey -- if it does then tracks like Barcelona will suddenly have overtaking chances and that's got to be good for the fans.”

Sauber driver and overtaking specialist Kamui Kobayashi also agrees the system could be very helpful in Barcelona, “In the past overtaking was particularly difficult on that circuit, but I believe DRS will help to make it an exciting Grand Prix. I feel very much at home using the adjustable rear wing. I'm happy with the system and I think it will be a real benefit for the Spanish Grand Prix's audience.”

I believe DRS will help to make it an exciting Grand Prix

Kamui Kobayashi

McLaren’s Whitmarsh is still optimistic about the rule changes that have spawned a barrage of overtaking maneuvers this season. “I’m particularly interested to see how the 2010 rule-changes affect Sunday’s Grand Prix. We’ve seen how DRS and KERS Hybrid have influenced the racing so far this season, so we’ll see how things progress at Barcelona given that the Spanish Grand Prix has previously shown limited opportunities for overtaking.”

And for the fans of statistics, the Finnish Turun Sanomat has kept a record of all overtaking manoeuvres this season. In Australia 29 passes were recorded, in Malaysia 56, a huge improvement compared to 2010, when 24 passes were recorded. Until the Turkish Grand Prix, China held the record with 63 passes, the highest number of passes recorded in a dry race in the last 20 years. Turkey now holds the record with 79 passes, the highest number since 1983. In total 227 passes during four Grands Prix, almost half the total of the entire 2010 season.

Who to watch this weekend

The favorites for the victory are the usual suspects: Red Bull, McLaren and Ferrari. Especially Red bull will be relieved the diffuser ban is postponed, which makes them favorite for pole position once more. Championship leader Sebastian Vettel is confident ahead of the race, “We know the Barcelona circuit well from winter testing -- it should be suitable for our car and our plan is to get the best team result possible.” Mark Webber took second place in Turkey and aims to step up his performance, “Of course I want to improve on my result in Turkey, so that means trying to finish on the top step. It would be nice to add to the special memories I have. It’s one of the best races of the season in terms of atmosphere.”

McLaren’s Hamilton has already won one race, and hopes McLaren will be one of the front runners again, “I think we didn’t meet our full potential in Turkey, and I’m hoping that the MP4-26 will be able to make a step forward if our initial testing on Friday goes successfully.”

Jenson Button has some catching up to do, “Turkey showed us that we are still on a learning curve with these Pirelli tyres, and while in Turkey it was a hard lesson to lose position due to strategy, I think it’s given us a lot of valuable lessons in how to work as a team, how to devise our strategy and how to get the most from the tyres out on the track.” And he added, “As always, the Circuit de Catalunya is a very unforgiving track -- it’s a track that brings out the best in cars. It’s important to get another strong result under our belts, particularly as we head straight to Monte Carlo, so maintaining momentum will be vital.”

Fernando Alonso, Scuderia Ferrari
Fernando Alonso, Scuderia Ferrari

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Ferrari’s Alonso is confident he will be quick in Barcelona, as he reckons the many test kilometres they have made during pre-season testing will make it easier to find a good setup for the car, but is concerned about the Pirelli tyres, “There is a big difference in that the ambient and track temperatures were very cold when we were here in February and now in May, it should be much warmer. This means there are little tweaks you can do to the car and setup adjustments to deal with this change in temperature. As it is a track that all teams and drivers know very well, it will be a very good reference point for the championship.”

Felipe Massa is especially concerned about the pit stops, as two badly executed pit stops did cost him points in Turkey. “It is important for every member of the crew to be a bit more precise, with everyone doing a perfect job consistently, because it’s no good having one good stop followed by a bad one. Everyone in the team is involved, including driver, with every procedure going into making it perfect,” the Brazilian said.

And he added, “In the past there was never much overtaking at this circuit and yes I think the new rules mean there will be more overtaking than usual, which is good for the fans as there is plenty going on for them to watch from the start to the finish of the race.”

It is also almost certain the number of overtaking maneuvers and pit stops will not equal the Turkish Grand Prix. Whatever happens during the Spanish Grand Prix, one thing is certain: Vettel will leave Spain still leading the championship, as his nearest rivals Hamilton and Webber are 34 and 38 points respectively behind him. His Red Bull team has so far collected 148 points, which could mean if McLaren takes the two top positions on the podium, and Red Bull would not score any points, they will have to share their first position with McLaren.

Follow all the action about the Spanish Grand Prix on this weekend.

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About this article
Series Formula 1
Drivers Jarno Trulli , Jenson Button , Mark Webber , Kimi Raikkonen , Fernando Alonso , Mark Blundell , Ross Brawn , Lewis Hamilton , Felipe Massa , Nico Rosberg , Timo Glock , Mike Gascoyne , Sebastian Vettel , Kamui Kobayashi , John Booth , Jaime Alguersuari , Martin Whitmarsh
Teams Ferrari , Mercedes , Team Lotus , Sauber , McLaren , Toro Rosso
Tags barcelona, berthold bouman, catalunya, fia, spanish gp