AC Schnitzer ACS4 BMW Z4 V8 Topster
The basis is the BMW Z4 3.0i, in which however "no stone is left unturned". The most striking optical feature is the enclosed bodywork, now 13 cm wider, in colors orange / cream.
The life-giving organ which was developed in record time as a one-off special in close collaboration with the BMW works team Schnitzer Freilassing, is the upgraded performance version of the 4941 cc eight cylinder, four-valve engine from the BMW M5. In conjunction with our technology partner, the engineers have equipped the V8 TOPSTER with special intake and exhaust camshafts. The cylinder heads have also been fine-machined, the compression raised to 11.5 : 1 and the control unit reprogrammed. To improve the exhaust gas flow, an environmentally-friendly special steel high performance exhaust system has been developed with twin chromed racing tailpipe trims in right and left combination. Power: 331 kW / 450 HP Maximum torque: 520 Nm 0 - 100 km/h 4.5 seconds Top speed: 305 km/h.
These figures are not only the result of the new engine but also a perfect combination of high engine power and optimally adapted power transmission. To match the power of the engine, the drive train and rear axle were also modified. The rear axle, with a gear ratio of 3.62 : 1, has a variable differential lock from 0 - 100 % depending on the load of the V8 TOPSTER. In addition the AC Schnitzer "Short Shift" is fitted.
Perfect retardation is provided by the AC Schnitzer high performance brake kit. This uses larger brake disks of 365 x 32 mm at the front and 328 x 20 mm at the rear in conjunction with special brake calipers (2-piston on the front and single-piston floating caliper on the rear). Even after several "hard brakings", the system achieves deceleration values of 1 g and more.
In motorsport the correct set-up is often decisive for a victory or podium place, and our development engineers place particularly great importance on optimum suspension settings. In the V8 TOPSTER the driving dynamics are decisively improved by the special development of a 9-position adjustable AC Schnitzer racing suspension. As well as lowering by 35 mm in relation to its distant relation - the standard Z4 - the spring and damper rates have been substantially modified towards more sports performance. In addition the wheel bearings and front and rear control arms have been replaced.
To counter sideways body roll, AC Schnitzer developed anti-roll kits on the front and rear axles. A further suspension highlight is the aluminum strut brace which optimally prevents torsion in the vehicle front.
The AC Schnitzer V8 TOPSTER keeps contact with the asphalt through the brand-new racing rims Type IV. The sporting yet elegant 5-spoke wheels have particularly fine filigree work. The individual spokes which run star-shaped from the pentagonal wheel centre to the polished bed perfectly complement the avant-garde TOPSTER outfit. But the wheel and tire combination is not just an aesthetic highlight. With sizes 9.0J x 20" ET 18 with tires 255/30 R 20 (front) and 11.0J x 20" offset 0 with tires 305/25 R 20 (rear), the TOPSTER can corner at speeds otherwise reserved for a thoroughbred Touring Car.
Source: AC Schnitzer press