DEARBORN, Mich. – Driving Ford Mustang is a visceral experience, combining a visual feast for the eyes with a seat-of-the-pants feeling on the road and the audible entertainment of a powerful engine. Like a film without a soundtrack, a Mustang without the right engine growl just wouldn’t be complete.
“Our goal in developing this new generation was to create a sports car that is quintessentially Mustang, with contemporary, world-class levels of performance and refinement,” said Dave Pericak, Mustang chief engineer. “We created an exceptionally solid platform to give us the flexibility we need to meet our diverse range of targets.”
Shawn Carney, powertrain noise, vibration and harshness engineer for Mustang, is tasked with making sure no matter what engine is installed, every new Mustang sounds like a Mustang should. Like great cinematic sound editors and composers, Carney crafts the soundscape that enhances the pony car driving experience.
Laying down a solid foundation
Film crews head to a sound stage, and musicians to a recording studio to get a clean backdrop to build on – free of unwanted noise. Similarly, Carney and his diverse team of engineers worked with the rest of the product development crew to craft a more refined background for the Mustang soundtracks.
“In addition to the usual suspects you expect to hear inside the car, like the engine and exhaust, the body structure can become an incremental source of unwanted noise,” explained Carney. “Body panels can act like speakers, amplifying vibration and sound inputs from the road, powertrain and wind.
“The Mustang engineering team – from studio, chassis, body, powertrain, dynamics, NVH and aerodynamics – collaborated to create an improved platform that attenuates many of the noises drivers don’t want to hear,” he added.
With more than a decade of experience working on Mustang NVH, Carney was handed responsibility for delivering the powertrain sound quality for all Mustangs. With three engines including a new turbocharged EcoBoost® offering, a 3.7-liter V6 and the legendary 5.0-liter V8, Carney and team set out to deliver three unique aural experiences – all while maintaining the common thread that connects the Mustang heritage.
Mustang’s sleek new profile helps diminish wind noise while also reducing lift and drag. The stiffer structure provides a rigid platform for more precise handling and improved ride quality, while transmitting less mechanical racket and road noise into the cabin.
Key design details – the shape of the alternator housing’s cooling vents, additional layers of door seals, acoustic windshield and the subtle lines of the mirror sails – all contribute to lowering the noise floor of the new platform.
The V8 engine rumble has long been considered the mating call of Mustang, so the GT receives a revised exhaust system to lay the bass note and set the rhythm from the first crank of the engine. Upfront, a redesigned induction sound tube matches the beat of the exhaust – note for note – playing directly into the cabin. The tube is now more centrally placed for a more natural balance.
The upgraded 3.7-liter V6 engine now has a more refined growl that communicates the performance a driver can expect from 300 horsepower underhood. Engineers borrowed a few tuning tricks from Mustang GT to provide this V6 with a grownup, though still very racy sound. Heads will turn as the new 3.7-liter Mustang storms by.
Composing a Modern Classic
The newest addition to the Mustang powertrain lineup is the 2.3-liter EcoBoost engine. With 310 horsepower and 320 lb.-ft. of torque, this powerplant ranks well up the list in the pantheon of Mustang engines. A combination of turbocharging, direct injection and twin independent variable camshaft timing helps this compact mill churn out nearly 135 horsepower per liter and more than 139 lb.-ft. of torque per liter – the best-ever power density from a production Mustang engine.
“Based on our long experience with V8 and V6 engines, we already had a good idea of what those Mustangs should sound like,” said Carney. “The new Mustang EcoBoost needed to have its own voice and its own DNA, while still being linked to the other models.
“We knew the EcoBoost was going to be straightforward and refined,” he added, “but it also had to project its own essence while still being unmistakably connected to the brand.”
The team benchmarked a variety of great cars, many of which had their own unique sounds that reflected the character of the vehicle. None were considered right for Mustang, but all had something to offer. Carney deconstructed key characteristics of those sounds, then arranged the notes to produce a soundtrack that matched the targeted character of the Mustang EcoBoost.
“Using computer simulation tools that take into account the basic hardware we have to work with in a given car – this defines the limits of where we can acoustically take a car – we created several sound concepts,” said Carney. “We enlisted our core audience, and solicited feedback from multiple Mustang enthusiast groups to confirm our direction for the EcoBoost sound.”
Even though the 2.3-liter EcoBoost beats the performance levels of earlier V8 engines, the physical characteristics of a smaller-displacement turbo engine meant it wouldn’t sound like its bigger brother, nor should it. The greatest performance cars in the world use a wide range of engine configurations, and each produces a distinct soundtrack.
The team ultimately decided on a sound that is athletic and youthful to accompany the nimbler platform of the all-new Mustang. At the same time, the Mustang EcoBoost has a traditional American feel, emitting a low-frequency sense of powerfulness that is a subtle reminder of the DNA it shares with the V6 and V8 Mustangs.
The EcoBoost engine incorporates a balance shaft for smoother operation, and even gets a unique mounting subframe with active hydraulic engine mounts to provide an uncommonly smooth idle. When paired with an automatic transmission, Mustang EcoBoost also adds a pendulum damper in the torque convertor. Manual transmissions use a new dual-mass flywheel for a smoother driving experience.
Just as a producer in the studio can rebalance frequencies to get the most harmonious sound from a band, Carney has similar tools at his disposal with active noise control. Microphones are mounted in the cabin to measure what the driver hears and provide real-time feedback control. The audio system is used to generate opposing sound waves to cancel out undesirable frequencies – such as low-speed “boominess” – while simultaneously amplifying the “instruments and notes” that reinforce the car’s strength, responsiveness and addictive power.
“Our goal with all three powertrains was to provide the driver with an engaging experience including clear feedback about what the car is doing at all times, but without isolating the driver from the action,” said Carney. “When tuning the sound quality of any Mustang, I often describe what I do as “letting you hear what you feel,” and aiming for that which is unmistakably Mustang – regardless of what engine is in front of you.”