Technical review: Spain and Monaco

John Beamer reviews the technical developments at the Spanish and Monaco Grands Prix.

Barcelona and Monaco couldn’t be more different in what they demand from an F1 car.

Barcelona is the ultimate test of aerodynamic efficiency, whereas Monaco is a drivers’ circuit, which rewards ability and confidence more than anywhere else on the calendar.

With that in mind let’s take a look at how the teams updated their cars for two very different races.

Red Bull in Spain

So what is special about the Circuit de Catalunya to earn it its moniker?

Turns three and nine in particular demand unending downforce. The Red Bulls were able to navigate turn ninth flat in sixth gear with an exit speed of 160mph – a shade faster than their entry speed and about 10mph up on McLaren, Mercedes and Ferrari. That gave the team a big advantage on the long run down to turn ten.

In contrast the final sector is slow. It consists of a series of third gear turns, a chicane before the sweeping final corner on to the pit straight. Traction is key, particularly exiting the chicane, to allow drivers a good run onto the straight.

Drag increases as the square of speed and teams that opt for more downforce pay the penalty in greater drag. That’s especially true for Red Bull which generates raw downforce from the upper surfaces of the car rather than from the floor. It’s speed disadvantage into turn one was about 6mph.

So how on earth did the the Red Bull pull out a second gap on the opposition? Not only does the car generate phenomenal amounts of downforce, as its predecessor did, but in sector three, the slow section, the RB6 was able to pull out three or four-tenths. Incredible.

Last year it was precisely the slow, twisty sections where the RB5 struggled. Go back two or three years years to the Ferrari/McLaren ding-dongs and a car that was fast in the high speed corners tended to struggle in the lower-gear turns. Somehow Red Bull has turned conventional wisdom on its head. How?

It’s hard to say for sure but Red Bull has a markedly different design philosophy to the other leading teams and it is that radicalism that probably gives the Milton Keynes-based outfit its edge.

For a start the RB6 runs a pull-rod suspension system. This is partly because of the decision to try to sculpt the back of the car as tightly as possible. The pull-rod system moves the suspension components further down (lowering the centre of gravity) and also allows a tighter ‘coke-bottle’ zone.

That means air is less likely to separate. The flow over the diffuser and rear wing will be more consistent so generating higher downforce. Allied to this in the off-season the car’s suspension geometry was improved to give the car better traction.

Other leading teams, like McLaren and Mercedes, focused more on the exploiting the double diffuser.

The problem with the double diffuser is that it needs good quality airflow to operate effectively. Peak downforce on the MP4-25 will be high but it is the consistency that is lacking. Through the slower corners where air to the diffuser is more restricted the RB6 will likely give superior performance.

Red Bull in Monaco

Monaco is an altogether different beast. It is a bumpy street circuit where a decent drive can make half a second or more difference a lap – just look at the gap between Mark Webber and Sebastian Vettel, or Robert Kubica and Vitaly Petrov.

Monaco also demands a high-downforce specification although for a different reason to Barcelona. It is a low speed circuit, which means drag is far less of a concern.

It pays to load the car up with downforce as that will result in faster corner exit speeds. Aerodynamic efficiency matter far less.

In years gone by teams have developed one-off packages for Monaco but that was when there were fewer restrictions on extraneous bodywork. Now vanes and flip ups have been banned there is little teams can do other than tweaking wing angles or add an extra cascade or vane to the front wing.

In the rest of this article we’ll focus developments from the top four teams before rounding out with a look at some of the innovations from smaller constructors.

Mercedes

Mercedes was trumpeting its upgrade package more than most teams coming into Barcelona. Although unnoticeable to the eye the W01’s wheelbase was lengthened to get address weight balance issues.

Homologation rules meant that no changes could be made to the chassis so the front suspension arms were angled forward with a longer nose to keep the distance between the trailing edge of the front wing and tyre the same as per the regulations.

This serves to shift the weight back and should reduce understeer and reduces the load on the front tyres. This is important because too much weight on the front wheel takes the rubber out of its ideal operating window and lowers grip.

The longer wheelbase creates more space between the tyre and the sidepods. This yields a marginal aerodynamic benefit as the air has better odds of reattaching so the bargeboards can work better. Schumacher, who likes to throw the front of the car around, certainly thought it worked.

Interestingly Mercedes switched back to the smaller wheelbase car for Monaco suggesting the suspension alternations compromised traction, which is key for Monaco (although it could also be the shorter wheelbase car gives a higher steering angle, which is critical for Loews hairpin).

The long wheelbase version will be back for Turkey but it looks as though Mercedes’ weight distribution error will prevent the team from challenging the top three teams this year. How soon until Brawn focuses on the 2011 car?

The more visible changed to the W01 was the revised airbox construction. The inlet was moved down and aft, which left a central strut to act as the rollbar. It is an innovative solution provided the airbox works at with the same efficiency as before. By lowering the inlet air over the top of the car has a cleaner passage to the rear wing, which will improve downforce.

Read more: Mercedes’ radical new airbox pictured

McLaren

Like most other teams McLaren bought a big update to Spain. The front wing was the biggest change with the endplate being heavily redeveloped. McLaren has always had one of the simpler endplate designs to divert air around the tyres rather than integrate the endplates and wing elements like many other teams.

However, the update for Barcelona moved the MP4-25 in that direction. The endplate now features two vents. The aft inlet is also integrated into rear wing plane and is separate from the forward section of the endplate – for the first time there is now a gap. This secondary inlet then billows in a venturi-style duct

The idea is for the faster flowing air on the outside of the endplate to bleed through the inlet to energise the airflow underneath the wing in an area where the aerodynamic effects of the tyre will be felt. Faster air on the outside of the endplate will help twist the air under the wing away from the tyres.

It’s hard to say precisely how the wing-wheel interaction works – it is one of the most complex aerodynamic relationships on an F1 car – but the total package is aimed at reducing tyre drag.

McLaren also introduced a revised rear wing and diffuser. The diffuser featured a series of longitudinal channels on the upper deck similar to Renault’s version from China. These channels help keep the airflow attached, particularly in lower speed corners, which helps maintain consistent levels of downforce.

The rear wing was a little more radical. Although the regulations specify that the rear wing may consist of only two planes there is a 150mm unrestricted zone which allows teams some creativity. McLaren has etched two ducts opposite each other on the main plane which feeds air to a central slot. This central slot acts as a third plane and allows the MP4-25 to run at a higher flap angle and create more downforce. The F-duct works with this central slot to induce a stall and to cut both downforce and drag on the straights.

Ferrari

The Scuderia introduced its F-duct in Spain but dropped the device for Monaco. That was partly because the data from Spain showed that the F-duct wasn’t working quite as planned. Although the F10 managed to comfortably top the speed trap in lower speed corners the device actually trimmed downforce a tad.

Also there aren’t too many places where the F-duct is useful on the streets of Monte Carlo. There was also a suggestion that the F-duct stalled both the rear wing and diffuser whereas McLaren’s version only affects the rear wing.

Ferrari were one of the few teams to add extra winglets to its car for Monaco. A small winglet was added at the rear end of the shark fin cover in the 15cm free zone around the rear wing centreline.

Red Bull

The biggest change to the RB6 was to the bodywork towards the rear of the car which dropped away more. Tighter packaging around the engine and gear box improves airflow in the coke-bottle zone which increase the velocity of air over the diffuser. This in turn reduces the pressure gradient the diffuser has to work and creates higher and more consistent downforce.

Like both McLaren and Ferrari, the Milton Keynes-based outfit has also carved a small slot on the floor in front of the rear wheels. This allows air to bleed to the outer diffuser channels, again providing more consistent downforce. The exhausts were slightly repositioned to better feed into the diffuser. In addition the front splitter also had a small inlet through which air will funnel to the floor.

For Monaco, Red Bull introduced a revised rear wing, which takes advantage of the 15cm free zone around the centreline. The shark fin cover and airbox means that air here is at risk of separation. The RB6 now features two slots to manage this – one in the main plane and one in the flap. This is equivalent to having an extra flap which allows the angle of attack to be higher. It’s unclear whether this is adjustment was just for Monaco.

Other teams

The new teams all brought updates to Spain. Lotus had upgraded a lot of its bodywork and a trailed revised suspension system with inerters (pioneered by McLaren in 2005) to reduce vibration induced by the changing tyre load.

Despite the revised bodywork the sidepods still looked boxy and the packaging towards the rear is bloated. This will comprises both peak downforce and downforce consistency of the diffuser.

Virgin has focused the majority of its engineering resources on extending the fuel tank. This took away from development of other parts of the car although a more developed front wing was introduced at Barcelona. In Monaco Ferrari-style winglets in the 15cm rear wing free zone were introduced.

Read more: Updated VR – 01 ‘Limo’ gets triple diffuser

Renault has been one of the surprise teams this year and unlike the previous years its rate of development has been good. Over winter it upgraded the rolling road in its wind tunnel and since then the correlations between what they’ve found in the wind tunnel and what they’ve observed on the track have been much more accurate.

Its front wing continues to get refinements. The main plane appeared to gain a slot and the positioning of fences and flicks on the endplates were slightly altered no doubt to tweak the flow around the tyres.

Sauber had the largest performance leap of the second tier teams in Spain. The front wing was changed and at the back of the endplate was a horizontal fence which manages the wing-wheel interaction. A fast rotating tyre pushes air down and forward back towards the front wing. This causes a blockage effect on the front wing and costs downforce. The fence is designed to protect the endplate from this effect. Also the F-duct was reintroduced and seems to be working far more effectively than before.

Final thoughts

So, on to Turkey, which is a track that is mostly similar to the Circuit de Catalunya. Red Bull, McLaren and Ferrari have all promised more upgrades. It’s going to be very difficult for the other teams to close the gap.

Last year Red Bull proved it had the resources and process to develop a car over the course of the year – it won the last three races. Also the aerodynamic baseline is established and understood by Newey and his team. That is a huge advantage as it is easier to bring performance to the car. It feels as though the other teams are having to make more guesses about development direction than Red Bull.

Oh, and don’t forget the one second per lap advantage the RB6 has. It’s massive!

F1 technology

• Pictures: Alpine’s new front wing and more Suzuka updates
• Pictures: Red Bull bring first performance upgrade for RB20
• How teams have tweaked their cars to hit higher speeds in Jeddah
• ‘A horrible project’: Why duplicating Red Bull’s trend-setting suspension is so difficult
• Aston Martin, Mercedes, Haas and others describe extensive US GP updates
• Ferrari’s floor changes and five more teams’ Japanese Grand Prix updates
• Pictures: Nine teams reveal updates for Singapore Grand Prix
• Monza updates: McLaren make raft of changes to improve low-drag performance
• All teams bar Haas bring new parts for last race before summer break
• Red Bull’s rivals bring smaller upgrade steps for Hungarian Grand Prix

This is a guest article by John Beamer. Find more articles by John here. If you want to write a guest article for F1 Fanatic you can find all the information you need here.