In the age of YouTube, an exotic carmaker needs exciting overhead tracking video of its latest automotive thunderbolt to thrill online fans. McLaren Automotive ran into unexpected difficulty getting that shot. The McLaren Senna’s extravagant wings, spoilers, splitters, vents, and ducts so thoroughly battered the air that McLaren’s video drone crashed in the car’s turbulent wake, unable to surf the waves and vortices pouring from the car’s carbon fiber bodywork.
So, while there is plenty of important hardware to discuss including the RaceActive Chassis Control II linked hydraulic suspension system, the Monocage III carbon fiber chassis tub, the 789-horsepower M840TR twin-turbo 4.0-liter V-8 engine, and 7-speed Seamless Shift Gearbox, the Senna’s fundamental story is aerodynamics.
McLaren Automotive, you’ll recall, is the street car production branch of the McLaren Group that also includes McLaren Racing, the fabled Formula One team that won 12 world driver’s championships and 182 grands prix, the second-most victories in F1 history.
Ayrton Senna was McLaren’s most decorated driver. The Brazilian won three of the team’s world championships and scored his maiden F1 victory at the Estoril race circuit in Portugal. It's fitting that we've come to Estoril for our first drive of the Senna.
Ultimate streel-legal car
McLaren calls Senna the ultimate street-legal track car. It is built on an evolution of the Monocage II carbon fiber tub employed by the 720S, but with reinforcement that closes off the area immediately behind the seats, and it’s the stiffest chassis McLaren has built yet. One casualty is rear visibility. The 720S may be compromised to the direct rear, but the Senna only has a letterbox opening.
As the team that introduced carbon fiber to F1 in 1981, McLaren is master of the technology now. That is why the Senna weighs only 2,640 pounds dry. Compare that to 2,822 pounds for the Ferrari 488 Pista, a similarly track-centric beast.
The benefit of light weight is obvious during rapid changes of direction or when braking from high speed. Less mass makes both of these tasks easier. How much easier isn’t obvious, though, because of the assistance provided by the active aerodynamic systems and the active suspension, both of which are programmed to be invisible to the driver other than the stupendous performance.
“We aimed to make the car so that every person can drive it to the best of their ability,” explained chief test driver, retired IndyCar racer Kenny Brack. Linear, progressive, predictable response is the key to driver confidence, and those were the traits McLaren programmers built into the Senna’s electronic assistance systems. “The driver shouldn’t know what is happening with the wing angle,” for example, Brack said.
McLaren’s engineers tell us that the towering rear wing (reminiscent of the ones on the Huracan Performante and Corvette ZR-1) banks upward at a steep angle while cornering and under braking, to help stick the Senna to the track. And like the Drag Reduction System on F1 cars, the wing automatically flattens out into a lower-drag configuration for high-speed driving.
The car has to be balanced, front-to-rear, so hiding up inside the ducts beneath the front bumper are active dive planes (McLaren calls them aero blades) whose action mirrors that of the rear wing, though we can’t see them in action.