This is what happens when BMW loosens its neck tie just a little, digs into its toybox full of M3 spares, and starts to play.
The 1 Series M Coupé is a factory-built hot rod limited to 2452 units worldwide, of which only 71 were allocated to South Africa and all are accounted for already. It started life as an ordinary and still-full-of-zest 135i coupé, but with a waving of BMW’s magic M wand was endowed with all sorts of butch components borrowed from the bigger M3.
First and foremost is the car’s stocky new stance. It’s only 55mm wider than a normal 135i but those five centimetres translate into a set of four exaggerated wheel arches that look straight from a German touring car. The control arms and other aluminium suspension pieces are also taken from the M3’s parts bin, and bring the much wider 19-inch wheels and tyres closer to the 1M’s corners. Looks like a bulldog ready to pounce.
The wider M3 suspension will inevitably afford more aggressive yanks of the wheel in corners, but having recently tested a 135i with Beemer’s Performance kit I can confirm that you’ll hardly notice the modifications in day-to-day use. The 1M is firmer over bumps but still very usable on SA’s holey streets. A proper back-to-back track test would be necessary to explore the precise differences between the two cars.
What is very noticeable is this car’s rear differential. Also borrowed from the M3 and unlike a standard 135i’s, the diff is of the limited-slip type that will lock up to 100 percent if an inside back wheel spins. This is extremely beneficial on a racetrack where when booted out of a corner, the engine’s power can be wasted through a spinning un-weighted wheel. Thing is, when there’s enough power available (and there certainly is here) a locked diff will send both wheels spinning resulting in what’s popularly known as a drift. Apply throttle while turned irresponsibly and the 1M will slide sideways, so it’s best to feather the gas in order to extract the most from this upgrade.