Sentient Bmw

We sat at the dinner table with invited guests after a long day of test driving at the proving ground. We were a bit tired, and I felt the need to break the silence. So, I asked what their favourite kingpin angle was. Then we had a nice evening chatting about steering, vehicle dynamics, and sharing more or less truthful anecdotes from vehicle testing around the world.

As expected, I did not get an answer to my question, but it sure started an engaging conversation. This was not surprising, since, when it comes to attributes regarding steering and vehicle handling, the steering axis, or kingpin, literally takes a central position.

Front suspension complexity

Small adjustments to the steering axis to improve one attribute almost certainly lead to the degradation of other attributes. Also, once a satisfactory steering-axis orientation has been found, it might not be feasible for packaging or other practical issues. The constrictions are plentiful.

These complications apply when you rely on a traditional boost-curve type of power steering, which has been around since 1951. All of the complex considerations and trade-offs dramatically change when you go beyond boost-curve steering.

Beyond boost-curve steering

Blueprint Steering gives you full authority over what happens around the steering axis, both the wheel steer angle and torque feedback. What are the benefits? The first to come to mind is the steering feel itself; for instance, feedback true to lateral acceleration, a high-fidelity on-centre feel, and freedom from disturbances, such as torque-steer, pot holes, and many more.

What is not so obvious is that there is even a chance to reduce cost and weight – have a look at this article I wrote for Vehicle Dynamics International.

And there is more, not so obvious, potential for Blueprint Steering, such as a higher lateral grip, and brake stability and returnability, to mention a few. What’s more, Blueprint Steering is probably a necessity for a premium experience of 4-wheel torque vectoring.

With Blueprint Steering, what goes around the kingpin doesn’t simply come around the kingpin. Unless it is desired. This brings a new dimension of freedom to the design of vehicle front suspension yet to be explored. How would you take advantage of such potential?

About Lars Markström

Vehicle Dynamics Attribute Leader, Lars Markström, at Sentient is an experienced vehicle dynamics Engineer. Few know as well as Lars how experienced drivers – and non experts – perceive and act on road conditions and upcoming situations. In articles on this website, marked “By Lars”, he reflects and go into details about vehicle dynamics, its history and development.

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