Williams in 2007: Against the Grain

Williams have endured both peaks and troughs during their long history.

The 2006 season was one of the team's worst in recent years - the car was off the pace and unreliable. This was coming off another poor season in 2005 and the loss of BMW engines. It appeared Williams were in decline.

Yet the 2007 season was a turning point for the team - their revised car brought back the pace and the reliability that has brought Williams so many victories over the years. While many midfield teams were going backwards in competitiveness, Williams joined BMW Sauber in bucking the trend and enjoyed a stronger season.

Leading this turnaround was Sam Michael, the Williams technical director. He works with the two team principals, and manages both the cars design at the factory and the teams operation at the track. Always open and frank, Michael spent time talking to Autosport.com about the rise in fortunes of the team in 2007.

Design

One of the reasons behind the team's problems in recent years was the commissioning of the second wind tunnel. The tunnel diverted resources, and once in use proved to be out of kilter with the team's original tunnel.

"I think that we had a lot of problems through 2005 and 2006 because of the new wind tunnel," Michael said. "A lot of those things went away in 2006 before we designed the 2007 car."

Running aero programmes in two different tunnels is meaningless unless the result in one tunnel can be replicated in the other. This correlation is critical in making the most of the extra resource available.

"You'll never have perfect correlation, because things like tyre changes and new technologies become available in wind tunnel testing," Michael explained. "Correlation is always going to be an ongoing task, [but] the difference we now see between track, CFD and model testing is significantly less than what it used to be".

In designing the new car the team had a new engine to integrate, a second-generation seamless shift to develop and a rethink on their aero strategy.

"From a chassis point of view, it wasn't a radical departure," Michael said. "It was just trimming things down, being more efficient aerodynamically.

"I think that the probably the biggest changes were mechanical, although the car was different aerodynamically, that does not present any structural problems."

The engine supply deal from Toyota was critical. Being the team's third engine in three years, it was important to get the installation correct.

"On the mechanical side, with the new engine partner, Toyota, we had to repackage the engine, gearbox and back of the chassis," Michael explained.

"That was started at quite an early time, so it wasn't a big deal. Because we had time to package it properly, we didn't have the problems we had last year".

This relationship was relatively new for both teams, although Toyota had supplied customer engines before. According to Michael, the relationship was smooth from the outset.

"It was pretty good actually," he said. "On the engine front, it's been fantastic. We've got a relationship with Luca [Marmorini] who has supported us right from the off - their intention was always clear from the start".

Also, the relationship with Toyota was reversed, with a supply of Williams gearbox technology going to the Japanese team in a joint development programme.

"We also went for a completely new gearbox as well," Michael said. "That was quite a bit of work but was quite rewarding, because we ended getting significantly improved reliability".

With the largely-hidden mechanical package carefully planned and designed, the work to improve the car's actual pace was largely down to a different aerodynamic philosophy. This was evident at the launch, where the car sported much simpler lines, uncluttered by aero paraphernalia.

"Most importantly, on the aero is that we shed a lot of drag," Michael agreed. "We took a lot of stuff off the car that was on the efficiency line. Lots that stuff you could clearly see - winglets, things on the back of the engine cover, wings above the rear impact structure and triple roll hoops wings. A lot of those devices were working in terms of downforce, but didn't quite have the efficiency."

Not only did this approach help the aerodynamics, but Michael adds another surprising benefit: "That also helped us in the ballast too, as they shed quite a few kilos."

With all the design changes as well as the new single tyre supply to contend with, Williams could have ended up taking a wrong turn in design terms. This fear was soon eased.

"I think on the chassis we got very good indications straight away, when we first ran them [the 2007 Bridgestone tyres]", he said.

"It's something that we developed over the winter. I think in terms of set-up, the weight distribution, roll moment and aero balance, we changed those things to suit. Then in terms of suspension geometry and design, we did make some changes during the year, but we weren't that far away on those things."

Unlike many teams, Williams ran well with the tyres from the start and then throughout the season. As their package suited the tyres, the team didn't have the problems that others had to adapt during the year.

"I think there's still quite a big mix out there in terms of weight distribution and aero balance," Michael said. "Those two things, along with roll stiffness, go together as package.

"So one thing you can see there is obviously quite a few different ways of coming up with the same result. Normally, if you move weight forward you need a strong front wing, because you have to have to move the front aero forwards to recover the understeer that you are going to get".

Although proud of their achievement, the technical director admits they haven't found the only solution.

"Everyone has got a different philosophy on it and I wouldn't say there's one philosophy that's exactly right," he said.

"It pretty much comes down to what your aero is like and how you use the car at different stages of the corners. I know where our car is, but you never know everyone else's car".

It was not only the team's engineers who had the new tyres to contend with. "The drivers had to get used to them as well, as you had to drive the tyres differently," Michael said.

"The old tyres had a lot of front grip and you could use that grip right into the apex of the corner. You can't use the current tyres like that. You've got to use them in a different way. The drivers had to work it out themselves by trying different things, and that took some time. I think we got a reasonably good handle on that by the end of the year, particularly with Nico."

Nico Rosberg is topic that Michael brings up frequently in conversation. The Williams team tends to like its drivers to be a certain type of person. Rosberg, with his personality and of course his speed, obviously fits in well to the team. This supports the team's continued claims he has a contract and will not be released to McLaren to replace Alonso.

That said, Michael was also quick to point out the perceived gap between Rosberg and Alex Wurz's pace was largely down to tyres, and was shown especially in qualifying.

"I think that one of the things that Nico got quite on top of was getting the quick lap in qualifying," Michael said.

"The difference in the race was still there, but not as big as in qualifying. He was able to go very quickly and not over-drive the tyres, but make sure he got the most out of them."

The 2007 season

Throughout the year the car performed well at all types of track - fast or twisty tracks, high downforce or low downforce. Did this suggest that the team got the basic package right?

"I think it tells you you're going in the right direction" said Michael. "It tells you you're doing the right thing - that you've got the right people; you just need to do more to catch up. Until you turn that corner, you've always got those questions marks over whether you've gone the right way over set-up or design".

Despite such a consistent performance at differing tracks, Michael offered some insight to where the team did struggle.

"We still have ups and downs, still had stronger and weaker tracks," he admitted. "Probably Silverstone and Barcelona were our weakest tracks, with Monaco, Brazil and Montreal being our best".

All teams keep a track of their relative performance to each other, and one of the key measures is the gap to pole. Michael details the team's deficit.

"Our average gap to pole was about nine or ten-tenths," he said. "Some of those tracks we were down to five to six tenths, then some up to 1.5s. It's still a sign we have stronger tracks and weaker tracks, which is the same for every team".

While the team could find pace at most tracks, the results throughout the course of the season showed a mid-year dip in fortunes.

"I think that in the middle part of the year we had a bit of unlucky run," Michael said.

"In Monte Carlo we were genuinely quick, but because Heidfeld got in front of Nico at turn one, he was on a different strategy, so Nico had a lousy afternoon.

"Then in Montreal, although Alex did well after the pressure and got himself a podium, before all that stuff kicked off, Nico was probably up with the Ferrari and on a good strategy as well.

"In Indy we were very strong on race pace and had a nightmare of qualifying session, where we struggled to get the grip in qualifying. There were two races in the middle of the year where we weren't as bad as we probably looked."

Taking the ups with the downs, Michael pointed out that the closing races of the yea, saw the team really pick up pace, despite the rain-affected races masking the their competitiveness.

"In Brazil, Nico's qualifying was fantastic," Michael said. "His fuel-corrected qualifying time was within three to four tenths of the front row".

Indeed, the final race brought Rosberg his best result with a fourth place.

Development

With a fast package from the opening race, the team's development of the car was at the same time both subtle and highly visual.

On one hand you had the obvious adoption of differing front wing designs and, although unraced, Ferrari-like front wheel fairings. But there was also the much more subtle work around the diffuser and other aero parts. As ever, these were introduced in steps, as listed by Michael:

"We added developments to the car up until Fuji; it was a good step. That was only because we wanted to consolidate our positions; otherwise we would have saved for 2008. We also had a package for Monza, and before that, Silverstone".

The obvious changes, as explained, included the bi-plane elements above the front wing.

"There were three different ones," Michael said. "Two versions curving into the nose, and then there was one that went over the nose".

Michael added that the two versions joined at the nose weren't a major change.

"There wasn't a lot in those two designs," he said. "It was worth a little bit, but nothing fundamental".

The McLaren-like bridged version was geared towards a different function. Says Michael: "The 'over-the-nose' we used only at low-downforce tracks like Spa and Monza, just because at that downforce level, the flow is slightly different"

I asked if the bridged section produced its own downforce, or simply conditioned the flow the rear of the car.

"It's just conditioning the flow over the car; it creates a slightly lifting section."

Michael went on to explain the reasoning behind this, and other devices that create lift at the front of the car:

"Because of the low downforce level, you have so much potential in the front wing," he said. "As you climb up the front wing curve, anything that shifts the centre of pressure rearwards without losing downforce allows you to recreate the aero balance by putting on more front wing. Then, you have more total downforce".

In simpler terms, the lifting shape of the bridged front wing makes the rear end work more efficiently. Thus, more front wing can then be added to have more downforce for no change in drag.

For most teams, this will only work when the front wing can provide more downforce than the car can use. This tends to be at faster tracks.

"There are a lot more devices that work at Monza or Spa downforce levels, but they don't work at the maximum or higher levels because the front flap starts to peak out," Michael said. "You don't have the power in the front wing. Some people run them at high downforce tracks now as well, such as Ferrari."

From his observation, we can conclude that the teams that had started to add the cockpit fins and bridge wings had already reached a good stage of front wing development.

One unusual design element on the 2007 Williams was its high expansion diffuser. The lower beam wing was split like Ferrari's to create a taller central tunnel. Again, Michael was proud its design.

"Our diffuser has quite high expansion," he said. "Probably the only team that's higher expansion in the centre was Ferrari, which tells you something."

Of course, the tall section comes at a price: "One of the biggest things when you go for a very high expansion diffuser is stopping them stalling. It's not a problem, but its something you have to keep your eye on."

In aiding the flow exiting the diffuser, Williams exploited a loophole in the rear bake duct rules. Many teams have added horizontal flaps to aid flow between the rear wheels and the diffuser. But Williams created a vertical element as far inboard as the rules allow. This almost lines up with the sides of the diffuser. Michael explained both the inspiration and the benefit.

"We couldn't really claim to do it first," he said. "Ferrari did that in Malaysia. We saw them running them in Malaysia, so we had some parts made for Barcelona.

"We call them rear brake duct vanes; they are a simulated continuation of the diffuser to continue that expansion a bit longer before it stops. But they are sensitive, because they change with ride height as they move up and down with the wheel."

Also taking cues from the Ferrari F2007 was the late-season testing of static front wheel fairings. Outwardly, these seemed to be drag-reducing items, but Michael said that their use went deeper than that.

"They very complicated actually," he said. " From the aero side, they're pretty complex bits of kit. We're still learning them, to be honest.

"They were ready to appear for the final three races but we had problems, not with the aero side, but with the mechanical side. You can imagine it's a bit complicated to keep something still while everything around it is moving. We had a revised design at Barcelona last week."

Williams's version of the wheel fairings differ from Ferrari ans Toyota's in the positioning of the outlets and the addition of a dimple at the 12 o'clock position on the fairing, although this latter feature wasn't linked to aerodynamics, it was more to do with the dimensional rules.

"The dimple at the top there was just for legality," Michael said.

"It's controlled by the plus/minus 160 height overall on the brake ducts.

"The other thing is that you don't want the disc touching the wheel, because when carbon rubs on magnesium it will cut through it like butter. Within a lap you won't have a wheel left, so you've got to be a bit careful you don't push for a bit extra and end up losing your wheel!"

The end-of-season Fuji upgrade wasn't covered in the technical reviews as the changes were almost imperceptible. "The things you could see from the outside were the difference in roll hoop wing changed positions, the flip-up end-plate area changed in front of the rear tyre, there was a change to the FWEP, and there were also a couple of changes to the diffuser that you wouldn't see."

Reliability

Compared to 2006, and also in comparison to the other teams in 2007, Williams had a good year for reliability. No gearbox failures and only one engine failure in qualifying were a major plus for the team.

"We still had four DNFs," Michael said. "But the car reliability in testing and races was a step forwards".

However Michael still isn't happy, and the team's history of challenging for championships shows that they still are aiming for the front of the grid.

"It's still not good enough to win a championship yet," Michael admitted. "That's what our target is, to have zero DNFs and that's what we need to win.

"The first one in Malaysia was a water fitting, a Williams part, and that failed, The second one was Indianapolis an oil leak from the oil tank, and the third one was when Alex had a fuel pump failure in Spa. That part was ours as well - they're all ours, really.

"The fourth one was, we had water in the brake pressure sensor in Fuji with Nico's car. That caused the traction control to start cutting in because the traction control uses braking pressure to know when it's braking. That was a really annoying failure."

While race retirements were rare, the team did have some issues in a few qualifying sessions. Again, Michael wa frank in acknowledging the problems: "We had problems in three qualifying sessions - Melbourne, Indy and Shanghai, then in Silverstone we had problem with misfire."

Most often, the tyres were the issue in getting the car into Q3.

"It's tyre warm-up," Michael said. "You can keep the tyres warm, but I think in some way we over-stretched the tyres on our car. But whatever it was that was causing on the Saturday, it was completely the opposite on the Sunday."

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