The Alpina B5 and D5 (F10) (also called the B5/D5 Bi-Turbo) are a series of high performance executive cars manufactured by German automobile manufacturer Alpina from 2011 to 2016. Introduced at the 2010 Goodwood Festival of Speed,[1] the car is the second generation of the B5 and succeeds the B5 (E60). Based on the BMW 5 Series (F10), the car was available in saloon and wagon bodystyles.
Overview
The B5 is based on the 550i and uses a modified variant of its 4.4-litre twin-turbocharged N63 V8 engine. The modifications include large 44 mm Honeywell turbochargers, reinforced cylinder heads, NGK spark plugs, high strength MAHLE pistons and an Alpina specific ECU. The maximum boost pressure of the turbochargers is increased to 14.5 psi. These modifications allow the engine to generate a power output of 507 PS at 5,500 rpm and 516 lbft of torque. The same engine is also shared with the B7 and the B6 convertible. The engine is mated to a modified 8-speed automatic transmission manufactured by