When testing out a McLaren supercar out in the wild, expect attention. Lots of it. People ask what you do for a living, middle school students stop in their tracks to stare and take video, and fellow motorists wave on the highway. The British companyâs latest achievement is the 750S, and itâs not only a piece of artwork on wheels in either the coupe or open-top body style, itâs a mechanical beast that zooms from zero to 60 in a blistering 2.3 seconds.
The 750S is rear-wheel drive and equipped with a 4.0-liter twin-turbo V8, situated longitudinally behind the seats and topping out at 206 mph. Itâs a sleek car that begs for a joyrideâwithin reason, of course, because no one wants attention in the form of a speeding ticket. And the spider version (in convertible form) is especially gratifying. All the better to hear the snarl, bark, and howl of all eight cylinders.
A symphony of engine and exhaust sounds in the 750S
At the helm of the 750Sâs impressive mechanical prowess is Sandy Holford, a 16-year McLaren veteran. As the chief engineer, his job is to bring together all the different experts at McLaren to get the best overall mix, or recipe, he says. Along with that mix is a distinct soundtrack, a specific roar that only McLaren can make.
Every car has a âvoiceâ and the McLarenâs is a crisp mid-level growl that sounds to my untrained ear as though itâs not quite as low as a Lamborghini and not as high as the clipped staccato notes of a Pagani. Once you learn the notes of the McLaren symphony, itâs unmistakable.
âWe donât focus on just exterior sounds; we review and score the exterior and interior sounds separately,â he says. âYou want the car to sound fantastic when it goes past, but as a driver, you also want it to sound fantastic when youâre inside the cabin. Both are equally important to us.â
The engineers donât target a specific decibel range for the 750S. Instead, they focus on acoustic quality, linearity, and crescendo. As the driver engages the accelerator, the sound builds like an orchestra pit in a powerful section of music, boosting engagement and connection to the car. Part of the sound comes from powertrain development, and McLaren did deliver increased performance with the 750S, but Holford states the primary goal for the vehicle overall was driver engagement.
âThat building crescendo is a direct response proportionally to your foot on the pedal, bringing that cognitive connection with the vehicle,â he says. âWe tuned it acoustically to give the 750S a sharp and distinctive, clear tone.â
The noise, vibration, and harshness engineers in Holfordâs department would explain they âreduced the second and sixth order sounds and allowed the fourth order acoustics to dominate, then pushed the eighth order sound to get that higher crescendo at higher engine speeds.â In non-engineering terms, they balanced specific sound frequencies to achieve a big, clear sound, rather than just big volume that doesnât necessarily represent the quality of the car. Picture a cheap stereo setup with a giant woofer, for instance. It can belt out the sound but itâs going to be a different kind of noise than if the same song was played on a high-end audio system.
When I left the house in the morning to take my son to baseball practice at 6:30 am, I wasnât so sure how the neighbors felt about that crescendo. But to me, itâs literally music to my ears.
More combustion, more pressure, more layers, more power
The 750S emits thrilling pops and crackles to accompany the music, like a drumbeat. Thatâs the combustion of fuel at play, entering the exhaust manifold and coming down the full exhaust system, Holford explained to me. Importantly, when in track mode thatâs a whole different story.
âItâs a combination of ignition timing versus fuel injection, so you end up with a little bit of excess fuel that then combusts as it heats through the engine cycle,â he says. âWhen you get to track mode, you donât want any excess fuel. You want every single piece to have been used optimally for that performance element.â
The secret to the 750Sâs insane acceleration is decreased vehicle weight and the additional power squeezed from the same engine used in the supercarâs predecessor, the 720S. Key factors are a combination of revised internal components and bespoke calibration, Holford says. That includes increased turbocharged booster pressure working together with twin fuel pumps that deliver more fuel and air. As a result, the 750S can combust more with greater power.
McLaren also upgraded from a dual layer to a triple layer head gasket to cope with that additional combustion within the engine.
âWhen there is more pressure in the cylinder, because we have more fuel and more air, it needs more compression and more resistance to keep that pressure within the cylinder,â Holford says. âWe have to go for a more robust ceiling interface from a dual layer to a triple layer to manage it.â
All in, the 750S is a poster car, the kind of vehicle thatâs often affixed to walls around the world as inspiration. Â
âThatâs the thing for me, when I see kids with their Hot Wheels McLaren car, or their [McLaren] T-shirt or whatever else, thatâs just fantastic,â Holford says. âBecause it shows what weâve done and how people are really appreciating and enjoying the products we make.â
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