Otherwise silent car interiors can now be
filled with “romantic” engine notes arranged for
electronics or acoustics.

Story By: Larry Crane

During the first broadcast laps of the 2014 Formula One season the twitter universe exploded. The auditory values of last year’s 2.4-liter V-8 engines at 19,000 revolutions per minute screaming through open exhausts ignited fires of enthusiasm around the world — they were extinguished in moments by the new season’s sadly muffled moans of a 1.6-liter V-6 exhaust trying to force-feed an enormous turbocharger at 15,000 revs before being unceremoniously expelled as a growl. The science is good. The end result of the new “power unit” is in the 900 horsepower range with track performance approaching or exceeding last year’s cars. But, initially, few race fans cared. The twitter blast was filled with a vast number of threats of audience drop-out — and losses of advertising revenue — an unexpected cost of extraordinary efficiency.

Contrary to popular belief, spectators at motor sports events are far less likely drawn to a noisy blend of paint colors being arranged in a bundle of twisted metal than by the harmonics of two dozen of their favorite engines being exercised at full song — in close quarters. If a harmony of sounds (symphony) is not what leaps immediately to mind when we mention a Ferrari 3-liter V-12 250 GTO at 8000 revs through megaphone pipes (a particularly appealing example), your heart rate might not be moved by the following essay. The distinction between cacophony and harmony is clearly in the ears of the mechanical cognoscenti.When GM released its EV-1 at the same time several recently introduced electric bicycles were terrorizing un-warned pedestrians, there was a rush of interest in developing a recognizable sound artificially, as a way to both give warning, and, concurrently and selectively, offer a satisfying tone to the virtually inaudible blend of motor hum and tire whoosh. Amplifying that melodious harmony was not the answer. Perhaps a set of sound system buttons by which to select a recording of the traditional aural output of hydrocarbons in combustion (Ferrari V-12, Corvette V-8, Rolls-Royce — near silence) delivered just under the incomparable strings of Django Rheinhardt or Christopher Parkening — both inside and outside. Both the science and the interest were carefully charted.

“Luxury” requires a predictable balance of comfort and quiet, while “Performance” necessitates a visceral beat with an audible harmony. The tools to deliver both are already in the automobile production lexicon. Turbocharging has offered useful horsepower from small engines that deliver admirable fuel efficiency for years. But turbocharging, by its very nature, driven by exhaust gas, acts as a muffler. That was quickly noted by the enthusiast culture. In the new century of extraordinary performance — of everything — luxury, even in super sports cars, has surpassed the requirements of royalty and performance now defies physics while being wrapped in thousands of watts of pure sound. Half of the audience is disgruntled.For a century the automotive cognoscenti have taken pride in their ability to recognize favorite cars by distinctive engine sounds as they pass by; that, of course, the sound of the engine’s intake. Since the glory days of the muscle car and the creation of the European exotic car, corporations have carefully controlled and manipulated the intake sound to suggest the sound of that recognizable exhaust. Today, several auto companies have taken extraordinary steps to include some thoughtful volume of that enthusiast entertainment.
Control is now at every millisecond of the process, so the eerie silence of a contemporary automobile interior can be broken by what ever the manufacturer believes its buyer might enjoy. Cue the digital drums.The latest editions of BMW M cars use two small turbochargers in order reduce the time it takes one large one to “spin up” pressure. The M5 V-8 has one on each side and the I-6 of the M3 and M4 have one for each 3 cylinders, the performance result is as required; the audible result is as expected — enter the alternate track in the sound system that augments the engine sound under the music. Brilliant.

 

Porsche has a distinctive — and historic — voice (think ‘Sally’ in Cars). In the soundproof cabin of the new, luxurious 991 a speaker diaphragm can be selectively given access to the intake charge and its analog voice (acoustic channel) piped into the car for more sporting passengers, or it can be isolated by a simple valve for a quiet drive to dinner.

Ford has gone to a greater historic extreme in its Boss 302 track day special with a second set of exhaust pipes under the rocker panels with removable restrictor plates; not unlike the “cutouts” used on Duesenbergs, Mercers and hot rod Model T and Model A Fords for extra performance (noisy, perceived performance?) on the street or at the Mojave dry lakes during the first decades of the automotive century.

Mustang’s less extreme GT V-8 simply plumbs a resonator pipe just ahead of the firewall and the car’s civilized muffler system for a more melodious arrangement. There is also a turbocharged 2.3-liter I-4 EcoBoost that sounds, outside, like a vintage Maserati, and inside — serious.

Volkswagen has used a similar system for its GTI, but more recently introduced a “Soundacator” closer to the BMW system. Even Lexus with its LFA supercar needed to deliver a sound quite unlike its traditional isolation system. Yamaha’s Center for Advanced Sound Technologies was commissioned to chart the exciting arrangements for a 5000-watt backbeat.

The latest Maserati V-8s deliver a historically critical, sharp-edged bark as the revs climb, to a degree that will either raise your heart rate or your ire, depending on your sporting demeanor. The sound quality of the company’s soon to be released Kubang SUV has caused considerable concern among the engineering staff’s “tuning” team.

We anxiously await its release.We look forward to Tower Records opening a Car Sounds catalog online for those who have heard all the electric motor humming they can stand, and look forward to a “Ferrari 250 GTO” button on Pandora to improve their electrified experience.

BMW Photography Courtesy of V3LLUM.

Featured Photo: By Ed Brambley (“Engine”) [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0/)], via Flickr