German tuning shop AC Schnitzer unveils the ACZ4 5.0d project based on the E89 Z4 Roadster. The base model sDrive23i went through the tuning shop for a complete makeover and a heart transplant. The four-cylinder 2.0 liter turbocharged unit was replaced with BMW’s only tri-turbo diesel engine, the N57S 3.0 liter which in standard form produces 381 hp and 740 Nm of torque (546 lb-ft). But with an ECU remap, the power output was raised to 430 hp and 840 Nm of torque (619 lb-ft).

The power is sent to the rear-wheels via revised ZF 8-speed automatic transmission which works in conjunction with a limited slip differential imported from the E92 M3.

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To cope with the power upgrade and to increase the driving dynamics, the ACZ4 5.0d features sportier brakes and improved suspension. By losing 133 kg, the tuned up Z4 can now accelerate to 100 km/h (62 mph) in just 4.5 seconds with a top speed of 300 km/h (186 mph).

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AC Schnitzer says only once concept car was so far built since the 113,965 euros price tag might scare away customers.