We will continue to inform you about the progress of the new suspension kit for Roadster (NA) & RX-7 (FD).First,Last progress informationLet's take a look back at the suspension development process.

① Determine the spring specifications. (Determination of vehicle height and degree of sports)
(XNUMX) Determine the "damping force (N)" based on the unique damping ratio.
③ Create a ride by evaluating sensitivity.

Although it is a rough process, there is actually another process between ② and ③.

The damping force of "②" is the "total damping force" that combines the "extension side" and "contraction side" of the damper.Therefore, before moving on to Kansei evaluation, the total damping force must be divided into the "extension side" and the "contraction side".The criteria for the distribution are as follows.

・ First, determine the "damping force on the contraction side".The decision method is based on 90% of mass production.The reason why it is weaker than mass production is that if the spring constant is increased and the damping force is equal to or higher than that of mass production, a push-up will be felt.

・ Next, determine the "damping force on the extension side".
Since the total damping force has already been determined based on the damping ratio, the damping force on the extension side is calculated by the following simple calculation.

"Damping force on the extension side" = "Total damping force"-"Damping force on the contraction side"

Since the total damping force is the same, the distribution of "elongation / contraction" can be determined without changing the damping ratio.After this, the ride quality is created by sensitivity evaluation, and the final specifications are decided.Therefore, it can be said that most of the time spent on development is Kansei evaluation.

The table summarizes the final specifications of NA and FD.Please think that the numerical value is the result of calculating the specifications by the calculation on the desk and going through the process of sensitivity evaluation.By the way, the graph is a plot of the damping force for each piston speed of 0.05 m / s for easy comparison, and is actually a smooth curve.

"Out of print sports car update programThe mass-produced suspension kit, which is the centerpiece of "", has already been developed and is currently in mass production.Both are scheduled to be released in early March.I think we will be able to inform you on the website soon.Please stay tuned!!

Posted by A.Asanuma