4 Series (F32)

Production 2013-present.

We've finally finished development, and are so happy with the results. It has only taken us 17 months to get here!

Our initial observations showed that traction, ride and handling, and of course engine performance all needed dealing with. It was clear that the standard suspension package is not up to the job, but more surprisingly, the Adaptive M Sport suspension is very weak in body control when set to "comfort" and is typically stiff when set to "sport". Given it costs around £750.00 as an option, we would recommend it be left unticked when specifying your car. If comfort is your primary requirement, then the standard suspension may well be adequate. But if you want the car to handle properly, whether you have standard or adaptive damping, you HAVE to change the dampers for something that works properly.

What took us a little time was that the chassis didn't respond to the treatment we used on the E92 chassis. Even though we had softened the rear end significantly, we were still unhappy with the slow speed ride quality. In desperation, we started to experiment with stuff we'd never had to tackle before, and literally stumbled into the solution. This showed us that sometimes an itterative approach can be more productive than a calculated one. That's now stored in our memory banks for the next time. 

Where engine power is concerned, recent developments have allowed us to tweak the 435i engine beyond 400ps, and the amazing 435dx to 380ps. All of the "Additional ECU" strategies can be consigned to history, now the engine can be tuned the correct way.

Traction improvements are now almost mandatory in the form of the famous Quaife ATB limited-slip differential. With the 435dx, this car's traction isn't limited, but you start thinking about Alcon brakes instead....