When you softly ring a maritime bell, the sound echoes out peacefully on the sea breeze. Then, if you grasp the bell with your hand, the vibration immediately stops and the bell goes silent. It’s with the same principle that Yamaha’s Performance Damper absorbs and dampens vibration in a car to give it a more pleasurable ride (#1).
The external appearance of the unit itself is nothing more than a single rod, but inside it contains a shock-absorbing mechanism (damper). The Performance Damper is fitted directly to the car’s body and thereby adds greater stability to the steering, makes the ride more comfortable, improves the quality of the ride and makes the car more pleasurable to drive overall. Since the Yamaha Performance Damper was first used on the Toyota Crown Athlete VX (released in 2001 for the Japanese domestic market as a limited production model with only 300 units offered for sale), it has been equipped on some 500,000 cars (as of November 2016) that range from compact kei (light compact) cars to high-end vehicles, including as an aftermarket part for Volkswagen, Audi, BMW, Porsche and Volvo models (#2).
At Yamaha Motor, we have been developing and manufacturing automobile engines to supply to car makers ever since our joint development and manufacture of the Toyota 2000GT in 1965. Then, in the 1990s we took on the new challenge of developing ways to make cars more fun to drive. We asked ourselves if there was a way to bring out more of the performance of the automobile engines we develop and manufacture. If we could develop such components, they would surely make the cars more enjoyable to drive and ride in. This idea led us to begin developing automobile suspension components.
In 1997 we created and released a suspension system called the Relative Absorber System (REAS).* It connected the hydraulic components of the car’s left- and right-wheel suspensions in order to optimize the balance of their performance and thus contribute to improved ride quality and handling.
It was during the final development stage of the REAS that one of the engineers mumbled something that would lead to the birth of the Yamaha Performance Damper. At Yamaha’s Fukuroi Test Course in Shizuoka Prefecture, a 2.5-liter test car can easily exceed 200 km/h if it accelerates at full throttle after leaving the final turn and rockets down the long, slightly downhill straight. At that moment, the engineer thought, “The suspension is excellent, but it still feels like the body is shuddering ever so slightly.” Then he had a revelation: “If we can somehow absorb this slight vibration in the body, it might make the car more pleasurable to drive.”
An R&D project was launched and the search began for a way to inhibit that slight vibration in the body based on the hypothesis that the best solution would be to give the body more “viscosity” instead of trying to make it unnecessarily more rigid. This was because making the body thicker and more rigid wouldn’t eliminate the vibration. The shuddering couldn’t be stopped by focusing solely on rigidity.
However, it took a while to get all of the engineers involved to agree with this hypothesis. The predominant belief was that increasing the rigidity of the body was the best approach for improving a car’s handling stability. But while increasing the overall rigidity of the body might be an effective means for improving certain types of performance, such as lowering a racecar’s lap times, we determined it would not help in making the car “feel” better and more pleasing to drive.
The small team of engineers at the start of the project set out to verify that the direction of the development hypothesis was correct. They used planks of vibration-absorbing rubber custom-made to special specifications to connect the right and left sides of the car’s body. Then, they mounted the car with a prototype hydraulic damper. From there, they worked on adjusting the damper’s layout to fit the characteristics of the test car and fine-tuning the prototype’s damping force characteristics and strength. Within the course of just one year they had made the system ready for practical use.
The actual damper employed the same basic structure and operation principle as the suspensions on cars and motorcycles, in which the kinetic energy of motion is converted into heat by the resistance created by having the oil force open a valve and pass through a narrow passageway. It essentially ignores larger shocks but absorbs small movements and vibrations. The differences between the Performance Damper and a normal suspension are:
1. It is designed to attach directly to the car’s body, which does not move very much.
2. It has less than 1/100th the compression and rebound travel of a normal suspension and is capable of producing a highly precise amount of damping force for sliding speeds also less than 1/100th those of a normal suspension (#3) (#4).
“The fact that we were able to sense such small amounts of shuddering in a car is likely related in part to our test course having a flat, high-speed straight. It wasn’t about hard driving through corners, but rather concentrating on the way the car behaved when on the straight at high speeds. Our course allowed us to ‘hear the voice’ of the car’s body and that may have been a big part of our success,” reflects one of the engineers. In other words, the unique layout of the test course that was designed primarily for developing motorcycles turned out to be one key factor in the birth and development of the Yamaha Performance Damper. Today, the Performance Damper has been adapted for use as an aftermarket part for the TMAX automatic-transmission supersport scooter and for Yamaha snowmobiles as well (#5).
However, the Performance Damper doesn’t necessarily represent a major leap in damper technology. Its real significance lies in the originality of Yamaha in sensing the micro-distortions in a car’s body that no one had noticed before, considering them to be a challenge to tackle, and then employing high-performance suspension know-how garnered over the years to come up with a unique and creative solution.
*Relative Absorber System (REAS): An original automobile suspension technology that Yamaha Motor developed and put into practical use in 1997 to optimize control of the relative movement of the right- and left-wheel suspensions to improve the car’s ride and driving performance. Featuring a REAS valve situated between the shock absorbers of the left- and right-wheel suspensions, the system functions to smooth out lateral roll and improve the road grip of the tires, thus giving the vehicle both a more comfortable ride and excellent handling stability. This system is used on cars such as Toyota SUVs and Audi’s top-of-the-line RS 7 Sportback Performance model.