The world’s fastest touring car improves AGAIN.
It’s another challenge for glory.
The challenge was to increase both corner speed and drivability beyond what
has ever been achieved before in touring car racing.
BD7 2016 sets the precedent once AGAIN. The theme behind the new BD7’16 for
chief engineer Yukijiro Umino was "Super flat".
It was a bold idea and a big risk to reconsider the current world championship-winning
platform. Yukijiro and his team had to ensure they achieved a super low center of
gravity without affecting the car’s winning ways.
Clearly drived from thorough testing, smaller sized front and rear pulleys enable set up of each part in lower positions on the chassis, allowing overwhelming speed. This choice makes sense in many ways that further reduce the weight and diameter of the set by a gyroscopic effect to improve the movement performance of the machine as well as throttle response. In addition, the diameter is sufficiently large enough to ensure the damping suits the shorter shock length. Front universal double joints are now standard to ensure racing performance. We achieved the perfect balance because of the BD7’s high performance chassis, thoroughly refining each individual part, the racing spirit of YOKOMO.
Talking about the car's handling and stability, the most important issue is the center of gravity. The lower the center of gravity, roll and pitch due to shifting weight load decreases, reducing ground load variation for the individual tires, while also preventing attitude change, providing both calm and responsive driving. In turn, higher center of gravity (current among touring cars in any brand) makes it harder to stabilize the behavior of machines in the touring car racing scene, requiring measures to enhance the shocks and stabilizers to reduce pitch and roll, and tracking to track gap, such as high speed / high grip in recent years. Building on our accumulated know-how, we have made a surprising step forward by refining the basic performance of the BD7 2016
The front and rear drive pulley was reduced 6 mm and the drive axel was lowered 3mm. This reduces the gyro effect caused by rotating parts when racing (the effect will be less changes direction of the rotation axis), especially due to better movement of the roll direction, sharp crosscutting and cornering become possible. The throttle response is also improved by the weight of the pulley. Acceleration and electric efficiency has also improved during escape at the corner.
The front and rear bulkheads, which account for a large part of the overall chassis weight, are lowered 3mm at the top of the upper bulkhead. The upper deck is also lowered 2mm, which greatly contributes to the overall lower center of gravity. Lowering the roll center’s center of gravity reduces excessive roll when running at high grip. In particular, the recent heavy trend of over grip in the current race scene naturally works well at preventing high-side, as it can be set not to depend too much on the stabilizer, resulting in more neutral steering characteristics.
Lowering the shock Tower, which is in the highest position, contributes to the low center of gravity. It is 7.8 mm lower compared to the standard rear shock tower of the BD7 2015, significantly lower by 5.3 mm than the short shocks that are conventional options. The short shocks are standard bundled with kit.
The short shock is not only to reduce the overall length, but to increase capacity by expanding the cylinder’s inner diameter. The new super low friction short shock “II” expands the cylinder bore from the conventional 10.2 mm to 11.2 mm, significantly more than the older short shock capacity, more than 20% over the standard size Yokomo SLF.
Though previously told operation felt “peaky” when shocks were made shorter, due to requests for SLF short shock “II” suspension increase at high speed, we have provided higher steering stability. Also, it reduces the viscosity change due to heat while running, and fewer changes of characteristics during a race result in increased stability.
Front double joint universal shafts which reduce the power loss during steering operation are now bundled as standard kit. When running with a front solid axle as is the current mainstream driving style, the steering angle during high-speed cornering tends to increase, causing the sensation of stalling. Now equipped with the double joint universal shaft of the BD7, said to be a must-have among standard 2016 racing equipment, more natural turn and speed improvements have been achieved. Also, due to standardization of this part, the sale price of double joint universal shaft has been lowered to 4,980 Japanese Yen (tax not included).
YOKOMO B7-16C BD7 2016 Black Series Conversion Kit available here