The point where the damping curve rolls over is called the knee-over point. Some dampers will have more than one, but the knee-over point can influence ride quality, handling, and sometimes track predictability. There isn't a correct or best damping profile, it's up to driver preference and chassis/design goals. Having a knee-over point at lower piston speeds means that mid- and high-speed damping forces decrease, while only high-speed damping (like small cracks in the road or landing from a jump) is affected with a knee-over point that occurs at mid-to-high piston speeds.
We plotted each damper's front and rear profile, as well as the range of adjustment. Some have independent adjustment for compression and rebound, while others have one adjustment knob that changes both compression and rebound damping simultaneously. Some manufacturers have a single adjustment that adjusts rebound damping forces only, which many feel has more impact on ride quality.
Different suspensions will vary in damping force adjustment ranges. A narrow range isn't necessarily bad, as it gives a better resolution since the kit was designed with a specific spring rate in mind. More motorsport-oriented kits (like Moton) don't come with pre-selected spring rates and a wide range of adjustment is intentional, so damping force can be matched to the chosen spring rate.
Scales/car weight
Prior to any performance tests, we threw each vehicle (with a full tank of pump gas) onto the corner scales to get total weight and weight distribution. Some cars came prepped and completely corner-balanced for the driver's weight, trunk contents removed and a gas tank two-thirds full, while others were just set by ride height and spring preload.
The KW car turned out the heaviest, at 2829 pounds. Meanwhile, the race-like Spoon Sports car registered 2685 pounds (with the help of composite bodywork and lightweight aerodynamic aids). A net spread, then, of 154 pounds. Average weight came in at 2758 pounds with a median weight of 2757 and one standard deviation of 49 pounds, meaning 68 percent of the cars fell between 2700 and 2800 pounds.
Engine dyno
To ensure all cars were operating with similar power-to-weight ratios, we ran them on the Dynojet at 7s Only Racing, (located conveniently at Buttonwillow racetrack). In order to compensate for the difference in power, torque and power delivery between the 2.0 and 2.2-liter S2000s, we allowed for some mild bolt-on tuning, with headers, exhaust, and intakes. Our curveball constraint was that each car had to keep the stock ECU, since we know how tricky it is to make more power with the stock tune and high-flow parts. The dyno was also our way of ensuring that everyone had the stock final drive, as each car was dynoed in fourth gear.
We took the best pass from three back-to-back runs as the published horsepower and torque number. Ironically, differences in power were more apparent between the F20 and F22C engines than individual cars, even though Honda states the same peak power in the two engines. The overall difference was 24 wheel-hp, with the 2.2-liter engines making an average of 213 hp, while the older 2.0-liter engines averaged 198 wheel-hp.
All power and torque curves shared similar profiles (with the tell-tale VTEC dip), except for the Spoon car, which had a power delivery that was almost perfectly linear all the way to 7800rpm, 100rpm past the rest of the AP2s. Spoon's car also had a 7mph wheel-speed difference from the rest of the AP2s, even though it made about the same peak power.