BMW M3 CSL carbon airbox

The BMW M3 CSL is famed for its intoxicating intake sound, and we explore its origins

Even for a company that employs so many people rocking fast footwear, BMW Motorsport’s launch of a lightweight E46 M3 back in 2003 – the now iconic and appreciating CSL – was big news. Big because the regular M3 – with its 3.2-litre straight-six developing 338bhp at 7900rpm, and supported by a trick M differential, beefier brakes and an extensive development of the E36 M3’s chassis with bespoke springs and dampers and thicker anti-roll bars – seemed pretty handy as it was.

No matter. When the M3 CSL hit the streets, there were gasps. Here was a hardcore statement of intent. Here was a car designed to rescue the M3’s track-evolved credibility following the disappointingly tubby E36 years. The CSL had a carbonfibre roof and rear diffuser, aluminium doors, a plastic bootlid and lightweight 19-inch alloys shod with super-grippy Michelin Pilot Sport Cup tyres. It had lightweight bucket seats and a carbon-clad cabin. It weighed a whopping 110 kilos less than the standard M3.

> E46 BMW M3 CSL manual conversion package revealed by Everything M3s

And with 355bhp, courtesy of an outrageously in-yer-face fist of a carbonfibre airbox, larger diameter inlet manifolds and reprofiled camshafts, the full-throttle upshifts hurled at the rear wheels by the robotised-manual paddle-equipped SMG transmission could almost bring tears to your eyes.

Inside and out, the CSL looked svelte and suavely savage. Sounded it, too, that race-style carbon airbox, with its trumpet-contoured interior, extending the engine’s aerobic reach to exotic heights but also acting a little like a quality hi-fi amp, bringing extra definition and clarity to what was already a motor with a deliciously angry, but slightly muffled, acoustic presence. The stonking soundtrack and fiercely punctuated, neck-twanging acceleration positively urged maximum conviction and commitment from the driver.

Arguably, no six-cylinder engine from Munich has ever raised more neck hairs than the CSL’s. Tell the truth, few engines from anywhere have ever sounded better.  Within the BMW M division, the M1’s, maybe? A little louder but with more mechanical thrash and less acoustic power. An E92 M3’s, then? A properly edgy V8 warble but volume limited and far too civilised by comparison. The V8 M5’s, surely? A creamy baritone but hardly brutish. The CSL drowns it, kills it.  

It’s a sound that seductively asserts that the E46 CSL remains the most focused, hardcore M3 of the lot and more than repays all the effort the M division’s single-minded paring and honing injected into the driving experience. When you lean on that 355bhp at 7900rpm the CSL really feels like it’s doing an honest day’s work while howling for more. We can thank the carbon airbox for giving maximum effort such an evocative voice.

This article originally appeared at

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Categories: Road


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