Item Info

Production Year: 1969
Media Type: Photographic Prints
Source: Automobile Reference Collection
Notes:

Building Super-roadability into the NSU K 70

Every marque of motor car is known for a particular style or characteristic. For the NSU range, one of the most notable elements is arguably the superb road-holding common to the bread-so it is not surprising that NSU designers are determined to build even better roadability into the new K 70 than they achieved in the award-winning Ro 80. 

This picture shows one aspect of the painstaking development work being undertaken to this end. It shows a prototype K 70 undergoing trials on the skid-pan. The aim: to test the car's roadholding under the most extreme conditions. 

The circular track has an average diameter of 35 metres, and theoretically, the car should neither skid or slither, regardless of the surface onditions. In the picture, the driver is racing round as if his aim was to 'lap' himself, but in other tests, he works to rigidly constant speed of 23 mph. 

The purpose of this cornering at a regular curve and speed is to record test data essential to the design, test and development departments if they are to build in optimum roadholding and cornering qualities as standard features of the K 70 when it goes into series production. 

Measuresments are taken of the angle of side sway because, although centrifugal forces tend to make the car drift out of its circular orbit, the longitudinal axis inclines towards the perfect circle by precise cornering with the aid of the steering wheel- in other words, the positioning of the front wheels at the correct angle. In the event, this is discussed in terms of over/or understeer and the driver congragulates himself if the car displays neutral behaviour at varying speeds, on sudden changes of load (as with sporadic touches on the accelator pedal), or even during braking. 

Because roadability also depends upon the tyres, the testing programme covers tyre comparisons as well as design tests. 

To travel at the very high speeds necessary to record the requried readings would subject tyres to considerable distortion if the road surface was dry, so a powered spray keeps the circular track constantly watered. In the picture, the NSU K 70 is undergoing rigorous testings to the very limits of its capacity. The NSU test track manager has jumped aboard the pump to increase the water output by use of the hand throttle.