Audi spiced up the TT coupe’s world debut at the 2014 Geneva Motor Show with a little taste of what the car’s platform and powertrain could potentially achieve. The TT Sport concept car is propelled by 309-kW (420-hp DIN), 450-N·m (332 lb·ft) version of the production car’s EA888 2.0-L four-cylinder engine for 0-100 km/h (0-62 mph) acceleration of just 3.7 s.
The engine is pressurized by its turbocharger to 1.8 bar (26-psi) of boost, yielding rated torque over a range of 2400 to 6300 rpm. An impressive 300 N·m (221 lb·ft) is available from just 1900 rpm.
The concept engine’s specific output of 155 kW (210 hp) per liter exceeds that of Audi’s R8 LeMans-winner in 2001. “This high-performance power unit is an impressive demonstration of the power reserves available in our EA888 engine,” said Stefan Knirsch, head of powertrain development. “In the TT quattro sport concept, it demonstrates its full potential.”
The concept’s engine uses production technologies like variable valve timing and dual direct/port fuel injection systems, with some special parts to withstand the added boost. Aluminum pistons include integrated cooling channels and the crankshaft is ultra-high-strength forged steel.
The cylinder head is tailored to the higher loads and the crankcase is cast of a high-strength alloy. Peak power is at 6700 rpm and the rev limiter acts at 7200 rpm.
The quattro concept uses a dual-clutch transmission for fast gearchanges. It sends power to all four wheels, with the clutch pack located at the rear axle for improved weight distribution. The concept carries 54% of its weight on its front wheels, with 46% aft.
A wheel-selective torque control system shifts power from inside wheels to those on the outside during cornering, which shepherds the car through turns for more neutral handling.
Front suspension remains MacPherson strut and rear is four-link independent, but the suspension components are aluminum for reduced mass. Shorter, stiffer springs lower the sport’s ride height compared with the production TT.
The TT quattro sport is built on the regular TT’s MQB platform, with its steel unibody using hot-stamped steel components with very thin walls for minimum weight. The car’s exterior skin, doors and lids are aluminum.
The fenders are flared an extra 30 mm (1.2 in) per side to cover the wider 20-in wheels and tires. In racing fashion, the wheels are retained by center lock nuts rather than by conventional lug nuts.
Like a race car, the TT quattro sport wears a carbon fiber front splitter and diffuser. They combine with the trunk-mounted rear wing to create race-worthy downforce for maximum grip.
The cabin is wrapped in Alcantara fabric and has been mostly stripped of amenities such as armrests and speakers for weight savings. The racing bucket seats are equipped with four-point racing harnesses for race readiness.Continue reading »