MG ZT260 Technical

THE RETURN OF THE PRACTICAL BRITISH MUSCLE CAR

MG Rover Group has today (September 23, 2003) launched the V8 powered MG ZT 260 V8. The rear-wheel drive vehicle, available in ZT saloon and ZT-T estate car, powered by a 260bhp 4.6-litre V8 engine and with an awesome 410Nm of torque to deliver class-leading acceleration, is now available for customer order in the UK. With an on-the-road price starting at £27,995, the ZT 260 offers an unbeatable combination of price and performance.

Rob Oldaker, MG Rover Group’s Product Development Director, commented: “The MG ZT 260 V8 demonstrates our commitment to deliver cars of true pedigree and character. This is a truly rewarding car to drive. Our choice of a big, torquey engine has been vindicated as this is a deceptively quick and efficient cross-country car. The more you drive it, the more you appreciate its unique ‘muscle car’ character that flies in the face of our competitors’ trend towards buzzy high-revving engines.

“Its introduction means MG now has the broadest range in its 80-year history. The new V8 heralds the return of the practical British muscle car, and as an MG it’s obviously great value too.”

Overview

The ZT 260 is a fully engineered evolution of the front-wheel drive ZT. Clever installation techniques have permitted the larger capacity engine and rear-wheel drive power-train to be incorporated within the robust bodyshell, without major visual changes. Below the skin the platform is largely new with significant changes to many functional vehicle systems to accommodate the revised drive-line layout, to produce a car of great driving character.

Recently a development ZT-T V8 was taken to the Salt Flats at Bonneville, Utah where the MG achieved a maximum speed of 225mph from a specially tuned V8 engine variant.

Design and Development

The development engineers were briefed to deliver the ultimate antidote to an anodyne world. The challenges involved in transforming the drive platform and packaging a large capacity V8 engine into the existing front-wheel drive vehicle should not be underestimated. Advanced computer techniques were used to package the new hardware without sacrificing the strengths of the established ZT platform. Sophisticated modelling techniques were used to refine the kinematics of the completely new multi-link rear axle configuration and to ensure that despite the revised engine installation, the car continues to meet the latest standards for occupant protection in all its markets.

Given the magnitude of the changes, it is no surprise that ZT has been extensively tested, seeing action in climates ranging from the bitterly harsh conditions of the Swedish winter through to the burning heat of high speed testing in Arizona and Australia.

Body Structure

Externally there is little clue to the extent of body structure changes necessary to accommodate the new rear-wheel drive powerunit, indeed ZT 260 shares the same acclaimed style of the front-wheel drive ZTs. Extensive changes have been made to the underfloor, with new designs for the front and rear floor, as well as an enlarged transmission tunnel to accommodate the in-line gearbox. A new manufacturing facility has been commissioned alongside the existing sophisticated ZT manufacturing line to ensure these changes to the body are delivered to consistently high quality standards.

Powertrain

The ZT 260 utilises Ford’s proven 4.6-litre V8 engine, widely used in North America to power the iconic Ford Mustang. Modifications have been made to the powertrain to assist in packaging the engine while MG’s engineers have also developed new intake, exhaust and emissions control systems to ensure the vehicle complies with stringent European noise legislation with no loss of power or torque. A new electronic engine calibration helps ensure the car exceeds current European emissions legislation.

The exhaust system, twinned for most of the length of the car, is distinguished by new quad-tailpipes. Outside the system produces a classic V8 burble, while inside the cabin remains quiet until aroused by the throttle when it resounds to the sporting note of a true thoroughbred.

ZT 260 features Tremec’s TR3650 five-speed manual gearbox, manufactured in North America. The unit has been extensively modified to meet MG’s needs and features unique gearing to suit the demands of European driving. MG’s engineers have also developed an all-new gear selection system and bespoke hydraulic clutch actuation to ensure precise and positive gear changes.

The rear axle features Dana’s Hydratrak® limited slip differential system, which utilises vane-pump principles to ensure continuous and seamless torque transmission to both rear wheels in the event of wheel speed differential.

Steering and Suspension

The ZT 260’s steering and suspension systems have evolved radically to match the performance of the V8 power unit. Developed by driving enthusiasts for enthusiasts, the team focused their efforts on honing the car’s classic rear-drive handling to provide seamless, fluid and adjustable attitude control under the widest range of conditions. The result is a car that blends day-to-day ease of use with the driver-rewards of a true thoroughbred.

Power steering, driven by a higher capacity pump, is now via a new forward mounted rack layout providing excellent feel and driver feedback to the leather-bound wheel.

The geometry of the ZT’s MacPherson strut front suspension has been tuned to the requirements of the new chassis platform. A new design of upright is matched to Eibach linear rate springs and a new, larger diameter anti-roll bar. Wheel response is controlled by Bilstein monotube struts, which combine a large piston area for fine tuning resolution with very high bending stiffness for improved camber control. The design employs a significantly revised subframe, which provides a stable operating platform for the chassis while also acting as a key loadpath in the event of a major impact.

A new multi-link rear suspension has been developed specifically for the ZT 260 V8. A new six-mount subframe houses the Hyrdratrak® differential, while each wheel is located by three lateral links (two steel and one light-alloy) and a light alloy trailing arm. Compound rate springs, also sourced from race specialist Eibach, work in conjunction with Bilstein monotube dampers to provide excellent wheel control. Roll behaviour is controlled by a new anti-roll bar.

Both ZT 260 models feature 18” alloy wheels; the attractive ‘Straights’ design is specified on the ZT 260 with a new ‘Apex’ 10-blade design on the ZT 260 SE. Contisport 225/45 ZR18 tyres balance excellent lateral stability with crisp, precise steer response.

Braking

ZT 260 has a new H-split braking system providing excellent stopping power. At the front, proven large capacity 325mm ventilated discs and sliding-pin callipers are specified. At the rear a new AP-Racing sourced brake system is specified with 332mm ventilated discs and opposed piston alloy callipers.

Interior environment

A new HEVAC (Heating, Ventilation and Air conditioning) unit is fitted to the ZT 260. The new unit is a water-blend design featuring a dedicated electronic control unit to drive servo-motor valves to regulate the water flow around the heating circuit. This system has been refined to offer similar levels of response and control to the existing ZT’s acclaimed air-blending system. All models feature ATC (Automatic Temperature Control), using the familiar user-friendly interface of other ZT models.

A discreet V8 badge in the centre of the fascia differentiates the interior of the car, while other aspects of the cabin environment are broadly similar to the existing ZT models.

A new moulding below the boot floor accommodates the relocated battery and the CD autochanger (standard on the ZT 260 SE). Major controls, which include steering, clutch and gear selection have all been refined to suit the ZT 260 V8’s more muscular character.

Black leather trim, highline satellite navigation that includes a Teletext equipped TV tuner and park distance sensors are but a few of the features that distinguish the SE.

ZT 260 V8 – Product specification