POISE AND PRECISION: HOW THE GRACE AND POWER OF FIGURE SKATERS INSPIRED THE NEW LEXUS LC’S CHASSIS
You might think there is a world of difference between the grace and power of champion figure skaters and the handling performance of a luxury coupe. But in fact the physical control and balance displayed by these sportsmen and women were an inspiration in the development of the new Lexus LC’s chassis.
Like many people, Masahito Watanabe, the deputy chief engineer responsible for the LC’s new GA-L (Global Architecture – Luxury) platform, is captivated by the poise, speed and precision these athletes display in their routines. Watching their performances, he realised the physics of how a skater controls their body mass could be adopted in designing a new vehicle chassis.
As a result, the new LC has the best possible inertia specifications, which means every part of its chassis is focused on achieving an ideal weight balance to give the car excellent agility.
Watanabe explained: “The position of the centre gravity is of crucial importance; it’s on a line through the middle of the LC’s body, with all components around it made as light as possible to promote excellent rotation. You can see how this works when skaters spin on the spot: they spin faster as they draw in their arms and legs, because the heavier parts of their body are pulled closer into the centre. We used the same principles of centring the mass for the new GA-L platform.”
At the same time, it was a top priority to make the centre of gravity – the point at which the vehicle’s weight is evenly dispersed, with all sides in balance – as low as possible to give the car excellent stability.
“Imagine a glass of wine,” said Watanabe. “A glass with a long stem places the heavier weight of the wine higher above the table, making it easy to tip over, compared to a shorter-stemmed glass, which is more stable. The same is true with cars – a boxy van with a high centre of gravity can tip over in a sudden, high-speed turn, but a racing car that sits low to the ground will not.”
But it wasn’t just relocating the centre of gravity and using lightweight parts that made this new platform special. It began with a prototype chassis created from a Lexus GS to serve as a research lab on wheels. This prototype, affectionately known by the engineering team as the “Franken-GS”, was driven on many different test tracks to evaluate ride and handling performance. Numerous adjustments were made until, after thousands of kilometres of testing, the ideal formula was produced.
“We used the GS chassis because it was front engine/rear-wheel drive and was closest in size to what the LC was going to be,” said Watanabe. “It wasn’t much to look at, but its beauty was in its purpose, helping us put our weight management theories to the test. We found we were able to significantly enhance the performance of the platform just by changing the inertia specifications.
This work brought about fine adjustment of the LC’s front-to-rear weight balance to 51.4/48.6, a lowering of its centre of gravity by 37mm to 513mm and an improvement in its yaw moment of inertia. For the driver this translates into a more reactive and stable chassis with limited body movement, and a flat, controlled ride through turns.
The intelligence gained from the “Franken-GS” was used to help build a working LC prototype from the ground up, complete with a V8 engine mounted low and behind the front axle.
Now attention could focus on the driver’s seating position, moved towards the centre of the car, set low down and with a hip-point close to the centre of gravity so that the driver can truly feel at one with the car.