Young Version — April 1998

Even with the same suspension, changing the power changes how the car feels. In the previous installment, as the first step in tuning the suspension to make full use of the turbo-swap power, we installed a production-spec A'PEXi N1 Damper. For the S14, its specification is F8/R6. Readers of the previous issue may remember that it rode smoothly and comfortably on the street. But with nearly 400 PS, the rear seemed weak. During circuit attacks, opening the throttle made the rear squat and the tires slide away. Even with the same suspension setup, the handling would have differed...

With a different tune, the car would have felt different, but for now the YV car had more power than the suspension could handle. To address this, we changed the shock damping. The resistance of the valves and fluid is what creates damping force! A'PEXi's N1 Damper uses a high-pressure gas monotube design and supports overhauls and detailed specification changes. This time, we left the front shocks as they were and tuned the rear shocks. See the next page for the changes and driving impressions. First, let's look at the shock...

Inside are valve shims. As the damper strokes up and down, they resist the flow of fluid (the oil inside the damper), creating damping force. Put simply, to increase damping force, increase this resistance. That can mean adding valve shims, making the valves stiffer, or changing the piston shape. It sounds simple, but choosing the right characteristics to work with the spring rate requires extensive experience and data.

A coilover suspension is not only for raising or lowering ride height by turning the spring perch. Its greatest advantage is that you can also adjust corner weight, which greatly affects handling. Corner weight is the load on each of the four wheels. By balancing the vehicle's static weight distribution, you can equalize cornering performance on the left and right—a true precision setup. This is common in racing: place the car on wheel scales and turn the spring perches until the diagonal wheel loads match. That balances the weight independently of ride height.