Project Nissan 240SX S13 Silvia Suspension - Lower Control Arm

1989 Nissan 240Sx S13 Suspension Joint Links

The rear suspension gets three adjustable, heim-joint links. The upper link, which the rear shock passes through, adjusts camber. The two lower links adjust toe. To make the most of the precision suspension motion offered by the heim joints, the rubber bushings on the outer end of each of these links should be replaced with Nismo hard rubber bushings. We haven't done that yet.

The rear suspension gets three adjustable, heim-joint links. The upper link, which the rea

The First Test
With the suspension, brakes and tires bolted on and adjusted to our first guess settings, we immediately took the Silvia on a 1,600-mile road trip to the annual All-Nissan meet at Mt. Shasta, Calif., and, more importantly, to that meet's open track day at Thunderhill Raceway. Our initial setup was -2 degrees of camber up front, -1.5 degrees in back, and just over an eighth of an inch toe in at both ends. Both front and rear shocks were adjusted to their 8th (of 15) stiffest setting. The handling was exceptional.

It's easy to see why the Silvia is such a popular drifting car. It's perfectly neutral at the limit, and thanks to the JIC spherical bearings in the rear suspension, it transitions to oversteer slowly and predictably. With the stock open differential, these slides usually ended in frustration, with the outside wheel finding grip, the inside spinning, and the slide coming to an abrupt, glory-free end. In higher-speed corners, however, even the open diff couldn't stop the fun. Spring and damping rates are perfect for the track, with enough surplus compression damping to encourage clipping apexes and bouncing off curbs.

At the test track, this setup yielded 0.92g on the skidpad, but felt like more grip could be found with some slightly less tail-happy settings and the added control of a limited-slip diff. Slalom speed was 69.6 mph, which is faster than a Miata or MR2, but we still think we can make it faster.

The Brembo/300ZX brakes, when mated to the 240SX master cylinder, feel ridiculously strong and more than just a bit touchy. The small master cylinder generates too much fluid pressure, and moves too little fluid, making pedal effort light and not as solid as it should be. We were also surprised to find the rear wheels locking first. A larger master cylinder and adjustable proportioning valve should improve both feel and stopping distances significantly. Meanwhile, the car stops from 60 mph in 130 feet, 8 feet shorter than it did with the stock brakes.

With all the dialing in that has to be done, our next installment of Project Silvia will focus entirely on how to sort the suspension and brakes. This next step is what separates the standard bolt-on queens from the rare and exceptional cars we call "sorted."

Goodbye, Rubber
7Suspension design is a constant battle between precision and ride quality. That battle was obviously hard fought on the 240SX. The rear suspension was state-of-the-art in its day, and is still seldom matched for sophistication or capability. Based loosely on a double-wishbone concept, the 240SX's rear suspension incorporates anti-squat geometry and multiple toe-control links for a passive rear steering effect. All this is compromised, however, by eight rubber bushings that add a surprising amount of slop to this precision design. Stop a 240SX from about 5 mph with the parking brake and you'll feel the car oscillate on these bushings.

Up front, the ride quality engineers clobbered the handling precision team by using giant, pillowy-soft liquid-filled bushings in the T/C rods. These sloppy bushings allow the wheels to move backward when encountering a bump, greatly reducing impact harshness, but simultaneously hurting steering precision.

Swinging this battle back toward precision can be accomplished with harder rubber bushings from Nismo or, if you're really hardcore, with these heim joint-equipped control arms from JIC. The JIC arms also add alignment adjustability where there was none before. The front T/C rod allows caster adjustment, while the rear links add camber adjustability and a wider range of toe adjustment.

The lower control arm is made up of two parts, a lateral control arm, and this trailing link or Tension/Compression (T/C) rod. To improve ride quality, Nissan used an enormous, soft, liquid-filled bushing to anchor the T/C rod to the car. We replaced them with these adjustable JIC T/C rods. The adjustment allows easy changes in caster, while the solid metal heim joint that replaces the rubber bushing improves steering precision at the expense of impact harshness.
The lower control arm is made up of two parts, a lateral control arm, and this trailing li
Brembo's Gran Turismo braking systems comes with everything you need, from the giant 13.1-inch rotors and Ferrari F50 calipers all the way down to a tube of Loctite and a hose for bleeding the brakes.
Brembo's Gran Turismo braking systems comes with everything you need, from the giant 13.1-
This isn't even funny. That little round thing in front is the stock front brake rotor. Surprisingly, this little 9.9 in. diameter and 0.8-in. thick rotor is the same one that came on the Silvia in Japan. Their cars didn't stop that well either.
This isn't even funny. That little round thing in front is the stock front brake rotor. Su