Editorials

Autocar and Birds have collaborated over the past 6 months on a project car, a BMW F21 M135i, by upgrading many different aspects of the model which are all included in the Birds B1 Complete Conversion package.

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"Our M135i out-punches the M2 by 25bhp and 51lb ft of torque, so it feels stronger through the mid-range and more urgent near the redline. But with less power to deploy to the road, and wider tyres with which to do it, the M2 does have...

"Working with BMW tuners Birds, we’re going to replace the standard, under-specified suspension with much higher-quality Bilstein components tuned specifically for the M135i, we’re going to fit a Quaife limited-slip differential...

"with the LSD fitted, the M135i is wonderfully controllable, the rear end breaking away in a completely fluid and controllable way. It's brilliant..."

Read Autocar's full review of the Birds M135i, equipped with the...