The Weissach axle (pronounced 'Vise-' as in 'advise' and '-ach' with guttural 'ch') is a special rear suspension arrangement devised for the Porsche 928. The goal of the Weissach axle was to eliminate lift-throttle oversteer by allowing the rear suspension to adjust itself during cornering maneuvers. The Porsche 928 is a grand tourer automobile made by Porsche AG of Germany from 1978 model year to 1995 model year, during which time it was one of their most expensive offerings. ... Trailing-throttle oversteer is a form of oversteer in an automobile. ...

The Weissach axle is a variant of the semi-trailing arm suspension. The tendency of a vehicle to oversteer when decelerating is compounded by the compliant bushings found in most trailing arm suspensions. When the vehicle is decelerating, the trailing arm pivots towards the rear as the wheel is "pulled" backwards relative to the chassis. This results in toe out, which makes the vehicle unstable. A trailing-arm suspension is an automobile suspension design in which one or more arms (or links) are connected between (and perpendicular to and forward of) the axle and the chassis. ... Ideally, when the car reaches the turn, the driver will steer it along the line marked with green dots. ... Toe is the symmetric angle that each wheel makes with the longitudinal axis of the vehicle, as a function of static geometry, and kinematic and compliant effects. ...

For the Weissach axle, the front pivot bushing of the trailing arm is replaced by a short link. In this arrangement, when the vehicle decelerates and the wheel is "pulled" back, the result is toe in. This adds to stability and thus, reduces oversteer. Volvo used the axle the axle in the Volvo 360. Toe is the symmetric angle that each wheel makes with the longitudinal axis of the vehicle, as a function of static geometry, and kinematic and compliant effects. ... Ideally, when the car reaches the turn, the driver will steer it along the line marked with green dots. ... The Volvo 300 series consisted of the Volvo 340 (initially badged 345 and 343) and Volvo 360 The Volvo 340 is a rear wheel drive hatchback and from the mid-1980s onwards saloon developed in The Netherlands shortly after Volvo took over the DAF car company. ...

A similar, but simpler concept to the Weissach axle is seen in the rear suspension of the second generation Mazda RX-7. Instead of an extra link, a special bushing is used in the same position in the lower control arm to perform a similar function. The Mazda RX-7 (also called the Ẽfini RX-7) is a sports car produced by the Japanese automaker Mazda from 1978 to 2002. ...

Suspensions with this or a similar function are sometimes called "passive rear steer". The concept of passive rear steering has fallen out of favor for new car designs, as semi-trailing arm suspensions have almost completely given way to multi-link designs with dedicated toe control arms. Steering is the term applied to the collection of components, linkages, etc. ... A multi-link suspension is a type of vehicle suspension design typically used in independent suspensions, using three or more lateral arms, and one or more longitudinal arms. ...

Name

It is named after the town of Weissach, where the research centre of Porsche is located and the axle was developed ^[1]. Weissach is a town in the district of Böblingen in Baden-Württemberg in Germany. ... This article is about the auto company. ...

References

1. ^ http://content3.eu.porsche.com/prod/company/history.nsf/deugerman/milestonesthe_seventies| (Retrieved Oct. 20. 2007)

External links

• AutoZine Technical School site
• UK Car - Weissach axle description and diagram.
• Porsche 928 history