Press Release
The bodyThe body of the new TT Roadster is built at the Ingolstadt plant in line with the ASF principle, using an innovative composite structure of aluminium and steel; like its predecessor, the painted bodyshell is then forwarded by rail for final assembly at the Györ plant in Hungary. ASF stands for Audi Space Frame, the ground-breaking aluminium technology that the brand developed at the start of the 1990s.
The supporting structure of the Roadster body is made of extruded aluminium sections and die-castings; a large number of aluminium sheet panels form a positive connection and perform a load-bearing role within this structure. The individual components have various shapes and cross-sections – like the bones in a human skeleton, they combine best possible function with lowest possible weight.
In the body of the new TT Roadster, Audi has supplemented ASF technology with high-strength steel, which accounts for 42 percent of the overall weight. Steel components are used primarily at the rear of the floor assembly. The reinforcing bulkhead that plays a key role in the Roadster, as well as the doors and rear lid, are likewise made from steel. The developers were thus able to achieve an optimum distribution of axle loads and consequently dynamic handling.
The bodyshell of the TT Roadster weighs 251 kg; were it built entirely of steel, it would be 45 percent heavier. Unladen, the 2.0 TFSI tips the scales at a mere 1,295 kilograms.
Central zones of the body: the cast nodes
The percentage of wrought aluminium components in terms of the overall body weight are as follows: 22 % of sheet, 18 % of castings and 18 % of extruded sections. Castings are deployed primarily where high forces are introduced locally and where multi-functionality is required. A prime example is the A-post node – a high-tech component that connects the longitudinal member, sill, A-post and windscreen cross-member.
On the new TT Roadster, a large proportion of the extruded sections are made from innovative aluminium alloys that exhibit superior strength and therefore help to cut the weight even further.
The new-style ASF features properties that are ideal for a sports car. Compared with the already very good predecessor, its static torsional rigidity has risen by over 100 percent. The vibrational comfort on board is also exceptional; this is all thanks to high local rigidity at the points of introduction of the frequencies, improved soundproofing of the body and the specific design of the metal-panelled areas. The drivetrain and suspension, too, are acoustically optimised.
The new Roadster TT also sets new standards in terms of crash safety. The longitudinal members at the front end are made of extruded aluminium sections and castings. In conjunction with the front cross-member and the subframe, which is bolted to the forward structure at six points, this assembly reduces and distributes the energy that acts in a head-on collision.
At the rear end, there are large-volume members to protect the passenger compartment. High-strength aluminium profiles in the doors and robust side sections resist the worst of a side impact. Transverse extruded sections reinforce the floor of the passenger compartment. The windscreen frame, which is reinforced by a high-strength steel tube, and the rollover bar protect the passengers in the event of a rollover.
Both front airbags, which are activated in two stages depending on the severity of the impact, receive their signals from an early-responding up-front sensor located at the front of the vehicle. The belt tensioners and belt force limiters protect the driver and passenger, and a special mechanism pivots the pedals away from the driver's legs. Large-size head and thorax side airbags are integrated into the seat backs. In a rear-end collision, the Audi backguard system uses the head restraint to support the back of the head.
