AMG's Electric SLS rocks out

For petrol-heads the sound of an engine is music to their ears, but German hot Benz builder AMG took that a step further when it asked U2 to help develop a note for its SLS E-CELL electric supercar.

Running on electricity alone the E-CELL generates no substantial sound and the involvement of the Irish super group occurred early in the three-and-a-half year process of creating one.

But if you ever get the chance to ride in an electric SLS, don’t expect Bono to start singing ‘Even Better Than the Real Thing’ each time the accelerator pedal is pressed.

AMG head of engine and powertrain Friedrich ‘Fritz’ Eichler revealed the U2 approach was part of an experimental early stage of development “to make it (the sound of the car) feel free - out of the box”.

“But that didn’t work,” Mr Eichler added.

Instead, U2’s music, along with Pink Floyd and other bands, was a small part of a conglomeration of different sounds chopped up, analysed, broken down and reformed into an ‘engine’ note that is piped into the cabin via special speakers.

It took three engineers working full-time for three a half years in a dedicated studio to come up with the right sound.

“We sampled and we just figured it out… like a disc jockey,” Mr Eichler explained.

The only really identifiable noise is the 6.2-litre V8 M159 engine that powers the orthodox SLS AMG.

“It sounds very natural now,” Mr Eichler told motoring.com.au. “You have to bring the people from the internal combustion engine sound to the electric sound and you cannot do that with one step.

“You have to do that with small steps so the sound is quite similar to the combustion engine sound. It is a little bit different, it sounds a little bit more electric of course but it still has the genes from the internal combustion engine.”

Mr Eichler said the pitch of the sound changes as battery power drained from the electric SLS, as if the car is winding down. He also suggested that different sounds could be optioned for the SLS in the future, in the same way trim, wheels and other parts can be customised by AMG now.

The SLS E-CELL powers each wheel via an electric motor fed by a 60kWh bank of lithium-ion batteries. Power and torque outputs are 552kW and 1000Nm, and the car is claimed to accelerate to 100km/h in just four seconds.

AMG claims that at highway speeds the car has a 250km/h range, although that drops rapidly if the full 250km/h potential is exploited.

The electrified SLS is left-hand drive only and on-sale only in Europe. Deliveries don’t start until start June 2013.

Mr Eichler admitted AMG developed the soundtrack for the SLS not only for emotional reasons, but also to drown out the uninspiring whirr of the electric motors and stone spatter under the massive rear guards.

He also revealed AMG had dabbled with vibrating seats to try and make the E-CELL feel more like an orthodox vehicle with an internal combustion engine: “But that was rubbish. It didn’t work,” he admitted candidly.

AMG’s musical tuning isn’t limited to the SLS as the engine sound of the forthcoming A45 AMG hot-hatch has been inspired by a Rory Gallagher guitar riff.

“We developed a very special four-cylinder sound and the target was to make it sound like Rory Gallagher guitar playing,” Mr Eichler said.”I think it is pretty good.”

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