Alpina's New B4 S Is A 190mph, Twin-Turbo Beast

We love an Alpina here at Car Throttle, and the latest announcement from the long-time fettler of BMWs has really tickled our fancy.

The existing B4 is being replaced by the B4 S Bi-Turbo, bumping power from an obviously barely-there 410bhp to a much healthier 434bhp, and torque from a feeble 442lb ft to 487lb ft. Which is enough.

Alpina uses the current 4 Series as the base, including the 3.0-litre straight-six found in the 440i. Over two years, the company says, every aspect was improved, from the quality and exclusivity of the interior to the major engine tweaks.

BMW’s own single, twin-scroll turbo is binned in favour of a twin-turbo setup with optimised air-flow, a forged steel crankshaft and improved cooling. The turbochargers on the B4 S are bespoke to Alpina and provide a “near-instant” throttle response, says the company.

Peak torque is yours between 2000rpm and 5000rpm, while the engine revs to 7000rpm. That makes for a top speed of 190mph and 0-62mph in 3.9 seconds. It’s rear-wheel drive, too.

Power goes to the wheels through a ZF eight-speed automatic gearbox, although 20 per cent of the components have been “optimised specifcally for Alpina to ensure very smooth changes even in Sport mode.”

There’s a standard limited-slip diff tuned to Alpina spec, and the drive shafts have been strengthened to last under the increased peak stress. Another nice touch is a lighter Akrapovic exhaust, which enhances a “powerful yet refined sound quality.”

Priced at £63,000 for the coupe and £67,000 with an electrically folding hard-top, you get increased luxury inside, with thicker carpet mats, Alpina blue details and special Lavalina leather for the steering wheel. Navigation is standard in BMW Professional guise, i.e. it’s the one you want.

Even better, there are B3 S Bi-Turbo saloon and Touring versions on the way in two or three months’ time. The standard warranty cover is shared between BMW and Alpina, and the cars can be serviced by any BMW dealer. Or any garage that uses OE-spec parts, for that matter. We like.