Diesel in a high-performance roadster?
The terms ‘diesel’ and ‘roadster’ aren’t often used together, but the team at AC Schnitzer has changed that with their one-off ACZ4 5.0d concept. Based on the BMW Z4 sDrive 23i, the new sports car has been upgraded from top to bottom with the goal of creating a lightweight diesel sports car, and boy will it put a smile on your face.
The heart and soul of the AC Schnitzer ACZ4 5.0d is the 5.0-liter, turbodiesel V-8 engine found in the BMW M50d that offers a good balance of power and efficiency. The newly-implanted engine was boosted up to 430 horsepower and 619 lb-ft. of torque – a thundering hammer for the small sports car. Power is sent through a newly-installed eight-speed automatic gearbox with pedal sports shift. In order to handle the massive increase in power, a rear axle and limited-slip differential was taken from the E92 BMW M3 and installed.
Packed with the tuned turbodiesel, the AC Schnitzer ACZ4 5.0d is capable of reaching 62 mph in 4.5 seconds from rest and surpassing 186 mph. According to “Auto Bild sportscars” it is also the fastest diesel to race on the Sachsenring with a 1:37.22 lap time.
But the engine transplant was only part of the equation. As the automotive world focuses on improving fuel efficiency, AC Schnitzer has been concentrating their efforts on reducing weight and the ACZ4 5.0d has benefitted greatly.
The pounds began to drop off when the electrohydraulic metal folding roof system was replaced with a lightweight CFC system that sheds 198 lbs. The factory exhaust setup was upgraded to a unit that tips the scales at just 8.8 lbs. and optimizes backpressure. Even the wheel and tire setup was optimized and cut 55 lbs., for a total of 289 lbs. of savings. After all is said and done, the ACZ4 5.0d comes in at just 3,239 lbs.
Although the drop in weight significantly improves handling, AC Schnitzer wanted to give the ACZ4 5.0d razor-sharp dynamics so they modified the entire suspension. Here, a new racing suspension with fully-adjustable compression and rebound was added and lowers the overall height by 30 mm. A new set of lightweight high-performance brakes sit up front behind the new Type VIII forged wheels that measure 9.5J x 19 with 265/30 R19 tires.
Aerodynamics also get a big boost on the ACZ4 5.0d. The front fascia gains a new carbon fiber spoiler and carbon fiber sports fenders while two hood vents help to reduce engine temperatures. A two-piece rear spoiler helps generate downforce at higher speeds while a carbon fiber skirt integrates the centrally-mounted exhaust tips.
The final aspect of the conversion is inside the cockpit. AC Schnitzer started with a new set of velour floor mats and aluminum foot pedals and rest below the beltline. New carbon fiber racing seats embroidered with the ACZ4 5.0d logos are matched with painted trim pieces in orange.
The new AC Schnitzer ACZ4 5.0d was only produced as a one-off concept vehicle for product development to a customer’s specifications. If it was for sale, the car would be priced at 113,965 Euros. AC Schnitzer does offer the brakes, suspension, bodywork, wheels, and interior upgrades for the BMW Z4 model range.
AC Schnitzer ACZ4 5.0d Specifications
Displacement: 5.0 liters
Number of Cylinders: V-8
Maximum Horsepower: 430 / 316 kW at 4,400 RPM
Maximum Torque: 619 lb-ft. / 840 Nm from 2,000 to 2,400 RPM
-AC Schnitzer engine optics
-AC Schnitzer lightweight exhaust muffler system
Wheels, Tires, Suspension, and Brakes:
Wheels: AC Schnitzer Type VIII lightweight forged in bicolor orange.
Wheel Size: 9.5J x 19
Tires: 265/30 R19
Suspension: AC Schnitzer fully-adjustable racing suspension
Brakes: AC Schnitzer 6-pistion fixed calipers at front axle
-Carbon fiber front spoiler
-Carbon fiber front fenders
-Dual hood vents
-Two-piece rear spoiler
-Carbon fiber rear skirt insert
-Carbon fiber roof
-Carbon fiber trunklid
-Painted trim pieces
-Carbon fiber racing seats with ACZ4 5.0d logos
-Aluminum foot rest and pedal set
-Velour floor mats
AC Schnitzer ACZ4 5.0d Gallery
Source: AC Schnitzer