Mercedes technical director James Allison unearths how the W11 became the nearly gracious racing car. And why the competition is never any longer copying the successful car’s opinion.
The Mercedes W11 is virtually the gracious racing car. What could it carry out better than the W10?
Allison: Extra downforce, more energy, a minute bit better balanced between a lap and the lope distance. The 2019 car modified into an fine lope car, however it no doubt modified into a minute bit more difficult to keep it in pole space. There were reasons for that. As for our car, it modified into advanced to bag the front axle sharp sufficient.
You would possibly want to per chance also simply admire keep different work into three areas with the W11. Truly appropriate one of them concerned the rear axle. Why?
Allison: Any suspension kinematician will announce that altering the architecture of a suspension must most efficient expend exiguous steps. It is one of the essential few areas the place it’s good to per chance no longer experiment plenty on the racetrack. You cannot produce different tail sections to check up on something out. You originate no longer admire the time. Fortunately, the simulators and the virtual riding simulations admire gotten worthy better. They’ll in part relate you what results a substitute could per chance admire. On the opposite hand, caution is knowledgeable on this space.
We started work in April 2019. With this alteration, we had a correct opinion of what the torsional stiffness and the chassis traits could search treasure. However whenever you switch the tie rod from one cease of the wheel provider to different, you substitute the steerage traits of the rear axle under load. The extinct car had a co-steerage cease that barely destabilized the rear. This format precipitated the toe attitude to interchange under load. The unique space of the tie rod has diminished this cease and stabilized the rear. We proceeded cautiously and secured ourselves with calculations, simulations and riding within the simulator. In some unspecified time in the future of the check drives, both drivers quick had the feeling that the riding habits on the rear had improved vastly.
Which modified into elevated: the aerodynamic or mechanical revenue?
Allison: I’m able to’t relate you exactly how worthy the aerodynamics approach has been. However sufficient to warrant a smash check. Where the decrease wishbone is now, it’s some distance linked to the smash building on the attend of the transmission. Therefore it had to be a smash check. This takes away some space for vitality absorption on tale of or no longer you should cease the collapse of the smash building earlier than the obstacle hits the exhausting section of the wishbone.
In repeat to meet the guidelines, the smash must be fully gracious. It is main to hit the pinnacle prolong quick. It took us about a check runs. It modified into structurally a posh task. For the reason that wishbones on different hand are linked to a section of the transmission that is never any longer very solid. So we had to pork up the building of the gearbox. However it modified into worth it and solved the deficits within the riding traits.
Did that resolve the problems in insensible corners?
*Allison:*The eradication of this weak spot didn’t correct happen final winter. We’ve got been engaged on it since 2017. The 2017 Mercedes modified into impressive in rapidly corners however a minute bit embarrassing in insensible ones. It has been a gradual job to bag to the place we’re now. Even the 2019 car modified into very balanced in all forms of corners at some point soon of the lope. It modified into a must want to realize how the tire develops grip on the asphalt, reckoning on the form of asphalt, downforce, tire temperature and rubber compound. The downforce comes from the aerodynamics, the mass of the car, the weight switch, how springs, stabilizers and dampers are coordinated. The aerodynamics never work the same. It is some distance dependent on the distance of the car. How it rolls within the bends, how worthy it leans ahead and backward, how worthy the front wheels are turned, from the bottom clearance.
This matrix is the premise for the aerodynamics diagram. It presentations how the downforce changes on the front and rear as the car moves by a curve. The trick is to preserve the downforce on the front and rear as excessive as capability, correct as the form of cornering demands. This is what now we admire centered on for the previous three years. We stumbled on a formula wherein the aerodynamic platform works so that the tires are chuffed, the front ones originate no longer wear out earlier than the rear ones, or vice versa. That improved us on the insensible corners, and that is the reason the place most of the lap time is. What did we stop for it? The tip payment of the contact stress in rapidly corners on routes the place the most most well-known aerodynamic load is on the front tire. We originate no longer soar treasure we outmoded to, however we’re accrued correct sufficient.
How satisfied had been you with the DAS track adjustment?
*Allison:*It brought nearly every little thing we had hoped for. In theory, we wished to make expend of it worthy more, within the sense that the motive force would optimize it from corner to corner, from unique to extinct tires. That can admire influenced the steerage habits. On the opposite hand, it appears to be like that the drivers didn’t fetch it easy to make expend of the machine as a regulate mechanism. It wasn’t as flesh and blood as turning left or moral. Presumably in a accepted season with more testing choices and style steps we would admire managed to refine the machine so that the drivers can expend it worthy more. However it helped us to bag the front tires as a lot as temperature at some point soon of warm-up laps and restarting. It is a shame that we couldn’t bag every little thing out and that or no longer it’s banned for subsequent year. However we tag
How worthy better did the engine bag?
Allison: From the attitude of the chassis engineers, it modified into the same bundle with more horsepower. Quite about a work went into this. It modified into a supreme morale booster for our engine division, HPP, after they learn within the clicking that the Ferrari engine modified into better than their get.
In Silverstone and Istanbul you had been worried in regards to the tires. Did one admire something to preserve out with different?
Allison: We’ve got had problems with the rear tires being too sizzling within the previous few years. That made for hundreds of imperfect weekends. Silverstone is a track the place that can without problem happen. We keep different work into getting the tires balanced on both axles in their working window and keeping the jacket temperatures under regulate, particularly on stretches the place the tires could blister. We can put collectively that worthy better nowadays.
We correct didn’t carry out a correct job within the 2nd Silverstone lope. Within the most most well-known lope we one procedure or the opposite obtained by, and then within the 2nd lope we didn’t pay sufficient consideration to the problems from the most most well-known. We didn’t expend due care when entering a lope the tires had been too soft for and we didn’t space the car up accordingly. We started with the same setup as we did the most most well-known week of Silverstone and we had been hoping for a miracle. That modified into a classic get aim.
In Istanbul we’re talking a pair of utterly different scenario. Your complete grip on wet roads is dependent on whether the tire ground is soft sufficient to interlock with the asphalt. Soft or no longer soft is decided by the temperature of the tire. Although now we admire correct programs for warming up the tires, it modified into no longer sufficient in qualifying on this track that day under these prerequisites. We had been too in unhappy health-geared up. If the lope had most efficient lasted 20 laps, we would were correct as hopeless. However our setup paid off over the scale of the lope. That made the lope so attention-grabbing. Different other folks outmoded the tires in but every other procedure at different instances within the lope. You would possibly want to per chance search treasure a celebrity at instances, and then search treasure a loser again.
Why modified into the rear soar pork up in two parts this year?
Allison: We’ve got different households of rear wings with different supports. To be prison, I originate no longer even know when which modified into outmoded. All are designed to make expend of the DRS cease as worthy as capability, while moreover keeping the soar salvage. Which formula that the soar must ship the downforce in a controlled formula for which it modified into built. When braking, in insensible and rapidly corners, in hideous winds.
Whenever you produce it on the verge of stalling, then exiguous particles of dirt and even raindrops can aim the lumber to stall. This is why we want to admire a definite amount of leeway. Whenever you desire the suitable capability DRS cease, or no longer you should tear very finish to this restrict. So that the gargantuan piano reacts as if it weren’t there when the flap is up. The trick is to fetch the suitable compromise.