An overboost function boosts torque for short periods of full throttle acceleration to 369lb ft. By comparison, the M3’s naturally aspirated 4.0-litre V8 kicks out 414bhp and 295lb ft.
Read Autocar's first drive of the BMW 1-series M Coupe
With a claimed kerb weight of 1495kg, the 1-series M coupe will have a power-to-weight ratio of 224bhp per tonne – some 34bhp per tonne less than the 1605kg M3 but 14bhp per tonne more than the 135i coupe.
Also included as part of an enhanced driveline is BMW M division’s electronically operated M differential.
The 1-series M coupe’s chassis has been significantly upgraded from the standard 135i’s, including a 71mm wider track at the front to 1541mm. There is a 46mm increase in track at the rear, up to 1541mm. The ride height has been lowered by 20mm to give the new M-car a more ground-hugging stance.
The brakes have been borrowed from the M3, with 360mm vented and drilled discs up front and 350mm vented and drilled discs at the rear.
See the earlier leaked pics of the BMW 1-series M Coupe
The changes to the chassis have necessitated some obvious modifications to the standard 135i’s body, with heavily flared wheel arches. The 1-series M coupé also sports a deep new front bumper with an enlarged centre air intake and what BMW calls air curtains - vertical ducts on the outer edges that help to channel airflow around the front wheel arches and reduce aerodynamic drag.
There are also new air ducts incorporated into the front wings; they are used to extract hot air while reducing air pressure in the engine bay at sustained high speeds. Other changes include unique side sills, new exterior mirror housings, a subtle boot lid spoiler and new rear bumper.
Just three paint colours will be available: Alpine White non-metallic, Sapphire Black metallic and Valencia orange.
Inside the upgrades are subtler, with a set of sports seats, a thick-grip three-spoke M division steering wheel, reworked instrument graphics and a liberal covering of Alcantara.
See all the latest BMW 1-series reviews, news and video