The watts-link and trailing arm rear suspension in the first-gen SA (78-80) and FB (81-85) Mazda RX-7 is notorious for”binding” at the extremes – full extension and compression of the rear solid axle. In these situations the watts link and trailing arm bushings will be compressed and torqued to their limit, as they are solidly clamped to their mounting points.
By securely de-tensioning these mounting points, we can allow the bushings to act as a pivot joint, with significantly smoother operation throughout their range of motion. This creates a flatter suspension curve, rather than it ramping up as soon as the bushings engage.
Regardless of your application, casual driving, aggressive road, or especially track and racing, you can gain significantly increased articulation from your rear suspension from this inexpensive, at-home tuning technique.
Thanks go to Carl Perez (Rx7Carl) for his PBandJ Racing write-up for the source material – you’re a legend my friend, brap on. Continue reading “Watts link & trailing arm modification”