Alpina have updated their B3 sedan and B4 coupe/cabrio, now offering them as the with the ’S’ with a more powerful version of the 3.0-litre twin-turbo straight six petrol motors and are soon to replace the current non-S range.
The extra punch from the reworked BMW-sourced six-cylinder closes the performance gap even more between it and their corresponding counterparts from M Division cars: the M3 and M4. They now produce 324kW and 600Nm (up from 301kW) thanks to new a new pair of turbochargers and high-performance cooling system to keep both coolant and engine oil temperatures in check.
The torque figure remains steady at 600Nm from the current B3 and B4, which is already 50Nm more than the current F80 M3 or F82 M4, but it now arrives earlier at 2,000rpm and maintains peak twist until 6,000rpm.
For the sake of comparison, the S55 motor in the M3 and M4 produces 317kW and 550Nm from 1,850rpm to 5,500rpm. BMW also offers both models with an optional Performance Pack which increases output to 331kW in addition to revised suspension components.
Like before, the Alpina models use the 8-speed ZF automatic transmission in contrast to the 7-speed M-DCT dual-clutch of the BMW M model, with calibration and predictive algorithms unchanged from the outgoing B3 and B4.
There really isn’t much else to declare as different with this ’S’ update aside from the updated powerplant. Both the B3 S and B4 S will come as standard with rear-wheel drive but can be had with all-wheel drive, the 3 Series-based B3 S also comes as a Touring if a sedan isn’t to your liking, and the B4 S is also available as a coupe or convertible - as before.
