It was a miracle Project S2000 made it from San Diego to Los Angeles the day we bought it. The stock rear S-03s were so worn on the inside that there was no longer any rubber visible, the remaining steel belts actually reflecting headlights of the car behind.
Like any enthusiast would, we took the worn tires as the perfect excuse to splurge on some new wheels and rubber. Mackin Industries had just the rollers for the job: a set of black Volk Racing TE-37s. These days, people like to run 18-inch wheels or bigger on relatively small cars like the S2000. But since ours is going to the track, not MTV Cribs, a one-inch diameter hike to 17 inches is perfect.

Volk Racing provided us with a set of light 'n' forged TE-37s.
Off the shelf, it's tough to beat a good ol' fashioned TE-37 when it comes to light weight. The 17x7.5-inch front wheels weigh 15.6 pounds a pop, and each of the nine-inch wide rears weighs 17.1 pounds. Combined with the higher profile afforded by 17-inch rubber, the forged wheels should be pretty much indestructible on the road. And while we're not exactly sticklers for aesthetics, they look pretty darn good, too.
We decided to wrap our new metal in a set of BF Goodrich KDs measuring 225/45R17 up front, and 255/40R17 in the back. This front-to-rear ratio should keep a similar balance to stock, while adding a small safety margin to guard against the snap oversteer that plagues 2000 model year S2000s. We stayed relatively conservative with the tire compound for now, in an attempt to keep the car streetable and match grip with engine output. In the future, we'll install a host of power enhancers that will necessitate the increased traction offered by R-compound tires. When that time comes, we'll swap out for BF Goodrich's new (to the US) R1.
It's tough to improve on the stock S2000 suspension. The car comes with external reservoir shocks that, combined with well-chosen spring rates, make it pretty capable in the twisty stuff. But since we were about to add a couple of pounds of unsprung weight to each corner, we needed something with quick reaction time and good rebound damping. Something a little more geared for track use.
The answer came in the form of KW's Variant III coilovers. Built for the weekend racer, they offer independently adjustable rebound and compression, and we can pick our own spring rates before they get here. Given the wide range of adjustability and KW's reputation in racing, they should help fling the S2000 around The Streets of Willow, our local race circuit. And thanks to the stainless steel construction and the preset high-speed damping curve, they might actually be bearable during daily use.
We decided to stick with the recommended spring rates, which meant 515lb/in for both front and rear. The spring rates being equal may cause a pogo-stick effect at certain speeds in a car with a 50/50 weight distribution, but we're willing to take the chance in exchange for retaining the neutral handling of the stock suspension.

The ride height before installing the coilovers. We measured a 2.75-inch gap up front (first pic) and a three-inch gap in the rear.
Due to the limited travel of the rear suspension and the arc in which it travels, it's important not to go too far when lowering an S2000. KW allows for an adjustment range of 1.2 inches in the front, and an inch out back. That doesn't refer to how much lower the car gets to the pavement, it just means we can raise or lower the ride height over a spread of 1.2 inches or one inch, respectively.
You can make the car higher or lower than recommended by a small degree if you want, but KW suggests that the shock would then be out of optimal operating range. Based on the results we got when working within the recommended range, we see no reason to set the coilovers otherwise.
M-Workz in Gardena, California, is the end result of a lifetime in cars for a guy named Steve Mitchell. He's raced and built cars professionally for decades and he's spent the past 18 years at Nissan, engineering every imaginable aspect of its cars. So we figured he could handle the task of installing our suspension and corner-balancing the car.
 KW's Variant III with spring and helper spring. In all-stainless, it qualifies as automotive porn. |  Mitchell unscrews the shock tower bolts and lets the assembly down. |  To get the front shock and spring out, the upper A-arm must be unbolted. |