Tech Talk: interview with Geoff Willis

The introduction of V8 engines for 2006 was confirmed before the end of 2004, while teams already had the V10 in development for 2006. Additionally, the confirmation of the rule details came late, when some teams already had V8s running either as cut-down V10s or new, dedicated V8s. The FIA has mandated restrictions on internal engine dimensions and weight, as well as a ban on moving inlet trumpets and multiple fuel injectors.

All these changes will see engines with lower power outputs, from 900+ bhp, but with the change of format the engines are expected to vibrate more - the 90-degree V configuration not matching the 8 cylinders for a naturally balanced engine.

Honda Racing's technical director Geoff Willis says the problems with the vibrations were to be expected, "certainly the theory shows the V8 will have more vibration. I think we have anticipated that with some of our design features in our car, as I'm sure most teams have. We are not really seeing an issue about it, it doesn't appear to be causing us any issues on the car, in fact we've had two tests now and everything has been fine - hydraulics, wings and bits on the back of the car."

So it seems the expected issue with vibrations isn't going to dominate as one might have predicted. "I would say it's probably going to be a non issue," Willis agrees. "There are things you can do with the firing order on your engine installation in the chassis, but as you wind the revs up it may become more of a problem, we will see."

So with the vibrations not stopping the engines running reliably, the teams can focus on the power and how it's delivered. With a 20% drop in capacity, logic would suggest a similar drop in performance. But the march of development in F1 sees an annual gain of around 3-5% in power, so the target this year will be somewhat less than the 20% (around 180-190bhp) drop and probably around 750bhp.

With peak power somewhat easier to predict, the drivability of the engine - that is, the way the power is delivered - will be very different to the V10s. Says Willis: "What's changed in the regulations, as well as the reduction in displacement, is we cannot have variable trumpets, must have single injectors and quite a lot of materials limitation.

"All the engine manufacturers used the moving trumpets to smooth out the torque curve, giving you good peak rev torque and good pick up. Now there's more of a compromise to balance those. So that's making the torque curve rather lumpier and there are more issues to do with part throttle control, making the engine rather harder to map and to drive. A careful right foot is going to be more beneficial."

Offsetting this lumpier power delivery is the fact that engine power output is now a match for the tyre. In recent years, the V10s simply couldn't get their power down - the dreaded traction control cutting in to limit the power from overwhelming the tyres. This made the car's traction limited; the car could be quicker only if the tyres could cope.

"In terms of absolute laptime, the cars were traction limited in a lot of places with a v10," Willis explains. "Now that traction limit is different for two reasons: there is a lot less power with the V8, but we are going to multiple tyres for a race. So the tyre grip's gone up".

This leaves the teams with some new options in terms of optimum set up. "We are likely to take wing off the car to improve the top speed the lap simulations are showing," Willis adds.

With more drivable power, better tyres and aerodynamics the cars will be faster and slower at different parts of the track, overall lap times will be down but corner speeds and potentially top speeds may be up, "cornering speed will be up all the time through the corners, you are really just going to look at lack of acceleration once your no longer traction limited. But they will be accelerating for a lot longer down the straight; the v10s were able to get to the terminal speeds much sooner."

This changes the emphasis from getting a V10 car into position where its power gains the lap time, to where a V8 car will be looking at corner entry speed to gain lap time. This will also be a different discipline for the drivers, more akin to F3, where maintaining cornering speed is critical - no longer the aggressive point-and-squirt of the past few years.

Some drivers will adapt from the aggressive approach, some already have a more fluid style, and no doubt some drivers will struggle. With this point in mind, Willis clearly feels he has an asset with Jenson Button and Rubens Barichello as Honda's drivers in 2006.

"I think Jenson's driving style is much more suited to the V8 than some others," the Briton says. "I think the smooth drivers will be able to drive around the slightly less smooth power curves and not using the TC quite so much, and maybe there's going to be an advantage in that."

Unlike last year, the aerodynamic rules haven't changed except for one small area, where the bargeboards are no longer allowed to be lower between the front wheels. Willis says this small change was a safety issue, "to stop us ripping them off on the kerbs," and adds that "it stops dragging debris back on the track from minor offs."

With this stability in the aero rules, teams who struggled with the rule changes last year or made compromises to get some parts working have a another chance to regain the lost downforce from the wing and diffuser changes.

Two areas that most teams didn't get to optimise to the higher front wing and lower diffuser was the interaction with the suspension. This was either due to the structural reasons or conservatism in their geometry to suit the no-tyre-change rule.

Since the introduction of the twin keel, the "Keel" debate has laboured on - from teams not really having keels to the choice of single over twin keels. Keels are only a structural attachment between the lower front wishbone to the chassis, but the position right behind the front wing makes them critical in aero performance.

The offset of cleaner aerodynamic shape was weight or stiffness - something the chassis designers struggled to compromise on. In 2005, all teams except McLaren launched with singles keels (Renault's V keel is seen as a single keel derivative).

McLaren made a late change to raise up their front wishbones to make the "zero keel" - which is effectively not a keel at all, as the wishbone's mount direct to the chassis, like in the old days (except the modern high nose chassis force the suspension geometry into an odd drooped format).

What McLaren gained was that the clean underside to the nose and wishbones has been well placed to interact with the front wing to gain even more downforce and efficiency.

Importantly for the chassis designers, this set-up fed the loads into the stiffest part of the car without heavy and complicated keels. Toyota followed suit in the last three races. For 2006, many teams are tipped to adopt this format, and maybe the term 'keel' can be dropped from the F1 vocabulary.

Willis rationalises the decision on which concept to go for. "It really depends on what comes out of the various teams' wind tunnels programmes," he says. "I think that having the same aero rules for two years running means that it does allow the other groups to catch up a bit. It's not so much copying, as the physics are the same for everybody, so it's not surprising when people end up with similar packages."

But Willis does warn that "the car that won the championship had fairly conventional front suspension layout compared to the car that appeared to be faster but didn't deliver the goods in the end. If you were just going to work on the evolutionary path that's most effective, I'm not sure which way I'd say is the best."

Other area affecting the car's layout and aerodynamics is the V8 engine itself. The new engines will be a minimum length, not something that an engine manufacturer will struggle to meet. This gives the chassis around 90-100mm to play with, which in turn gives a range of options - from shortening the car to adding a spacer so as to retain the current wheelbase.

"Its really going to depend on what people want to do with weight distribution and where the wheels go," Willis comments. "This is possibly going to have caused the most problems to the car designers. If you've got enough ballast to move around then you can deal with it, but I know there are some people who do not have the ability to move enough ballast around.

"But as the aero rules are more or less the same, the engines in truth will be similar weight, because there is a minimum weight. My guess is the cars' layout will be fairly similar."

So as the gearboxes will be longer, the position of the gear cluster and differential may be changed in detail. The gearbox internals are something that has been a source of interest in the past year, with the so-called "Zeroshift" selection mechanisms. These are aimed at reducing the drive lost in gear shifting to a minimum.

One patented version of this is called Zeroshift, so the term could be misinterpreted. Instead, what we'll term "Quick shift" systems are believed to be in use at McLaren and BAR. This is a highly secretive area and one much misunderstood.

Willis does on expand on this area, but he says: "We suspect there are other very rapid shift gearboxes around and we strongly suspect others will be trying the same. It's not so much the shift speed, but how it integrates with the transients of the car during gearshifts. That's where the developments are - always trying to minimise the disturbance to the car mid-corner upshift and downshift without destabilising the cars.

"I don't think the shift speed in itself is that critical. With conventional gearboxes we were down to very quick shift times. Up and down the pitlane there's around a 30-millisecond shift, which is not a very slow gearshift. But there are other benefits in terms of simplicity of the inside of the gearbox and the gear sizes and various other componentry, all the time to minimise the bits you are trying to carry, minimise mass and inertia, but maintain reliability."

With the outright speed of the shift not as important as the quality of the shift to keep the car steady, Willis admits to a similar system being on the BAR for the past two years. "Our quick shift gearbox, or whatever you want to call it, was developed a couple of years ago and we raced it all last season and all this season.

"It's not the Zeroshift, which uses these bullets on the shaft to lock the dogs. It's a piece of gearbox technology largely developed by HGT - that's the Honda R&D plant in Tochigi, Japan, form which the F1engine and chassis programme come from.

"It's a concept that was refined by them and implemented with the F1 team, it's been one of the biggest of the joint projects, it's one of the areas where we did a lot of work and continue to work. It's an advantage of having the support of a major manufacturer."

Away from the mechanics and aerodynamics of the car itself, the other major technical rule change is the reintroduction of mid-race tyre changes. As a Bridgestone team from their inception and now a Michelin team for two years, Willis is well placed to assess the two tyre-makers' approach.

"There's a slight culture difference between Bridgestone and Michelin, certainly they both look at the construction of the tyre and compounding as two separate strands and they'll be looking at how they vary both of these things."

Willis further explains how his current relationship with Michelin is progressing: "We are discussing with them the consequences and implications of the rules changes and the V8. This is a very busy winter, when we get back to testing in January I am expecting a lot of testing to be done to get us back in to the multiple tyre formula."

This regulation U-turn will affect how the teams set up their cars and suspension, while the tyre suppliers have had a year of long-life tyres to apply to the new breed of tyres. This latter development is out of the hands of the teams.

Although the tyres will be used in similar race strategies to those in 2004, Willis doesn't see it as totally relevant. "I think they will be looking at which of the developments they made in 2005 can give the advantages in what we will now be doing. You have 2004 to go back to for a lot of information, but it is remarkable how quickly the tyre technology moves, and how relentless the rate of progress is."

The V8 engine's lesser power output will have impact in tyre design that perhaps was not evident initially. "As we'll have less power going through the tyres, tyre warm-up will be more of an issue," Willis explains. This will help the teams get the heat into the tyres - especially the rears - and maintain that heat during pace-car periods.

Again, the new cars will place less demands on the tyres as a result. "Also, the benefit will be on hot tracks, where tyre temperatures will be less of an issue," Willis predicts.

As already mentioned, the greater part of tyre development is done by the tyre manufacturers, but the teams still have design work in order to accommodate the new rubber. Willis sees the tyres as central to the car's whole design philosophy.

"Everything else you do on the car - aerodynamics, engine, whatever it is. It's got to communicate with those four contact patches." Of course, by this he means the suspension - still something of a black art. But the design software and simulations assists the engineers.

"The key is to get the tyre at its ideal orientation at all times," Willis says. "There are - with passive suspension double wishbone geometry - a number of conflicts between the best tyre alignment for traction, the best alignment for mid-corner, and mixed loads.

"So you will see all the teams working quite hard with both kinematics and compliance effects." By this Willis means the relationship between the angle that the wishbones hold the wheel at, and the way the springs and roll bars control the angle of the car.

"You might think you've got one tyre attitude due to the kinematic effect of the suspension geometry, but it's relative to the different elements which add their own geometry to that of the tyre orientation. What we are learning, as we work with the tyre manufacturers, is just what is the most critical factor with that tyre orientation.

"Then, there's the balance between having the tyre in its right position with the attitude of the car and how that will affect the aerodynamic performance. It's a very tough call and every year we learn another big step in how it works."

Willis continues on how Michelin assists in the process: "We have a very clear design guidance from Michelin; they have done a lot of work with the tyres at all sort of orientations, at different loads and slip angles. The trouble is, sometimes you can't get the tyre perfectly aligned at all times. Part of the skill of the car designer is choosing where to make the compromises."

The last change for 2006 is not a technical rule but still one that affects how the teams will tackle the car's design, and how they operate the car at race weekends. The FIA has announced - quite late in the year - the new format for qualifying, making it a more complex three-part session, mixing elements of the "one lap" and open-session formats.

"It is quite interesting," Willis comments. "I think the objective is to try to get the combination of the equal TV coverage of one by one - but with that sense of the old qualifying, where the dying few seconds of the session could see the epic shoot-outs, with pole changing hands four or five times.

"We certainly think that qualifying with fuel for the start of the race leads to quite interesting race strategies, so I think it was important to keep that. I think this is an interesting mix of those ideas; it's going to make for a busy hour. There's going to be no worry of twenty minutes of nothing happening and no worry of watching cars that are not that quick going one at a time while you wait for the top ten to come and show what it's about."

In the new format, all 20 cars will announce their proposed race fuel level. They then have an initial 15-minute session to set a laptime, and then the fifteen fastest cars will have another 15-minute session to set another time. At the close of this session, the ten slowest cars will be allowed to re-tyre and refuel for the race's start, albeit other parc ferme conditions apply.

Then, the last ten cars go out for a final twenty-minute session with the times zeroed for the final top-ten order. However, the final ten will not be allowed to reset their fuel load, having qualified with race fuel.

This opens up many avenues of strategy, and Willis expands on some of the options: "I suspect it will be relatively easy for the top ten cars to make sure they are in the top ten. The tricky bit strategically will be the cars that think they can only qualify P9 or P10 - then you might want to qualify P11 and get the opportunity to put a lot more fuel in.

"We are doing quite a lot of simulations to work out how we deal with it; I think it will take two or three races for it to shake out into a standard pattern."

Although, Willis warns, with up to 50 minutes of track time, we won't be seeing long runs of laps from the top teams. "You'll just need to make sure you've done a quick enough lap, you'll go and do a lap fairly early on, then you'll be watching to see.

"In the second fifteen minutes, you probably won't want to use up engine life so you'll try to do one lap to get you in the top ten if you're in a quick enough car. Then the challenge in the last session is how much do you want to put mileage on the engine versus how much do you want the fuel top-up benefit?"

There are speculations that the top ten cars will be droning around trying to burn off fuel in order to get a lightweight qualifying lap before being allowed to reset their fuel to the pre-qualifying level.

This has been intercepted by a rule agreed by the Technical Working Group, as Willis explains: "It looks as though the FIA is going to define a fuel consumption number, so for every lap you do faster than a certain percentage of pole, it qualifies for a top up. Say it's 2.5kg a lap, and you do you ten laps in the sessions, then on Sunday morning you are entitled to pump in ten times 2.5kg of fuel.

"What we didn't want was cars of vastly different speeds going around - it will encourage you to drive around and have a couple of goes. The interesting bit will be how late before the end do you have a go? Do you have a go and then have time to come in, stick on a set of tyres, and go back out again to cover it if you haven't been quick enough?

"My feel it that you will have done a practice lap in the untimed session in the morning, you will have done your first run in Q1 and a second run in Q2 - so you really shouldn't really need more than a go at it in Q3. But you will need to make sure it is very close to the end of the session to get the best track. It could be quite an exciting last few minutes."

This more strategic qualifying will lead into the race with the option to switch tyres. "Its going to be similar to 2004 with the mixture thrown in that the teams that qualify further back will typically be able to run longer, as they will have topped up to their optimum.

"So you'll find the last ten, if they do their sums correctly, will be fuelled to the qualifying position they got, whereas the front ten won't necessarily be quite as good. There could well be, by the first stops, a bit of swapping around in the midfield. Plus, it gives you another opportunity if you have a major problem in qualifying, by fuelling long and keeping out of trouble."

With the technical and strategic changes, 2006 will be a serious challenge for the teams. While it often appears that the major teams will adapt the best, a canny midfield team with the right design and strategy for qualifying could well spring a surprise.

Not least, the teams that struggled in 2005 from either the rules affecting aero or tyre life, could return to much better form.

We want to hear from you!

Let us know what you would like to see from us in the future.

Take our survey

- The Autosport.com Team

Read and post comments