Chassis tuning was also a major consideration. The design chosen permits the use of different torsion beam thicknesses and different attachment angles for the beam cross-section. This allows adjustment of rear-axle roll rate when combined with the various factors such as engine, vehicle weight and body style.

In addition the track is now 32 mm wider which gives more cabin space inside and improves road holding still further.


IDS Plus

The IDS concept was introduced on Vectra and has had further refinement for use on the new Astra - the first time this kind of chassis technology has been seen in the lower-medium segment. IDS Plus is available as an option on Design and SRi models. Vauxhall is confident that a new dimension of ride-quality can be experienced in the compact segment as a result of this new technology.

A combination of agility and a high level of safety were the development objectives. IDS is an electronic chassis network which integrates all the individual systems such as the Electronic Stability Program ESP Plus, Traction Control TC Plus, ABS plus Braking Assistant and Continuous Damping Control (CDC).


Sport program: more fun at the touch of a button

Another feature of IDS Plus is the SportSwitch, so that at the touch of a button the driver gets a firmer more sporting drive when the mood dictates. The SportSwitch regulates a number of essential functions including throttle pedal response, and the speed of the electro-hydraulic steering. And when combined with auto or Easytronic, the shift points are raised to higher engine speeds.

CAN
The basis for the communication of the various units is a new electronic architecture with three CAN (Controller Area Network) bus systems, the high-speed data bus being used for the particularly time-sensitive engine and chassis controls.

CDC
CDC damping system on the new Vauxhall Astra is based on four shock absorbers controlled by solenoid valves, which are continuously adjusted to suit road conditions, car movement and driving style to ensure high levels of ride comfort whatever the conditions.

UCL
Vauxhall engineers have developed a further function that is of real value in everyday situations and increases active safety. Given the name Understeer Control Logic (UCL), understeer is electronically controlled first by closing the throttle to reduce road speed, then by braking both front wheels. When the ESP 'control range' is reached, braking pressure on the outer front wheel is decreased and built up in parallel at the inner rear wheel until the car is back safely on course.

BA
A 15-inch or 16-inch brake system with discs all round means strong braking. In the event of an emergency braking - identified by sharp, rapid pressure on the brake pedal - the Brake Assist system immediately increases the brake pressure, shortening the braking distance.

The IDS Plus chassis will be an option on SRi and Design models in the UK while the Electronic Stability Programme (ESP Plus) can be chosen as an independent feature on most models, and is standard on SRi. It can be switched on or off by the driver.

The sporty SRi and SXi models also get a "sports" chassis lowered by 15mm over other cars in the range.

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