German tuner AC Schnitzer has installed a 424-horsepower 3.0-liter diesel
engine from the BMW 5-Series into a Z4 sDrive 23i (E89).
The BMW Z4 ACZ4 5.0d by AC Schnitzer is a one-off concept and will not be made available to customers.
The core of the conversion is the engine: the M50d power plant, used for example in the BMW 5-series (F10/F11), has been upgraded and implanted into the ACZ4 5.0d. This now develops 424 hp and has a maximum torque of 620 lb-ft (840 Nm). The series M50d engine has 375 hp and 546 lb-ft (740 Nm) of torque.
The rear axle gear and limited slip differential from the BMW M3 (E92) replace the standard rear differential, and the standard manual gearbox has been replaced with an 8-speed automatic.
The increased engine power alone however would not have pushed the power curve of the BMW Z4 ACZ4 5.0d by AC Schnitzer up quite so far. The other part of the equation is the systematically applied lightweight construction - some examples: the electrohydraulic metal folding roof and the boot lid have been replaced by CFC constructions. These optimizations alone account for a 198 lb (90 kg) weight reduction.
The standard silencer has been replaced by a lightweight silencer, which saves 42 lb (19 kg). A further 55 lb (25 kg) are saved in the wheelset - based on the AC Schnitzer forged alloys Type VIII - which combines rims in 9.5J x 19 inch with tires size 265/30 R19. As a whole, with a few further measures, 288 lb (131 kg) has been "trimmed off" so that despite the significantly heavier M50d power plant, the car weighs in at just 3238 lb (1,469 kg).
Additionally, the BMW Z4 ACZ4 5.0d by AC Schnitzer features a new suspension which lowers the body by 30 millimeters, interior trim elements in orange, racing bucket seats and aluminum pedals.
Equipped in this way, the ACZ4 5.0d by AC Schnitzer sprints from 0 to 60 mph in just 4.2 seconds, and can reach speeds of over 186 mph (300 km/h).
As measured by the Germany's Auto Bild sportscars magazine, the BMW Z4 ACZ4 5.0d by AC Schnitzer can lap the Sachsenring circuit in 1:37.22 min, fastest of all diesel-powered vehicles.