The right pieces make the difference
By Greg Raven
Photos by C. Van Tune
March 1987, page 80
Sooner or later every performance enthusiast starts to think about experimenting with different suspension set-ups in hopes of finding a combination that will work better than the factory-supplied parts. One year ago, the “hot” set-up was pretty easy to find. Recently, however, there has been some new activity in the world of VW suspension systems that has raised the state-of-the-art to new heights.
On past occasions VW&Porsche has looked at how various tuning firms set up their cars. This time around, we are going to spotlight Autotech SportTuning, in Orange, California. In addition to being one of the largest sellers of aftermarket performance parts and accessories for the VW enthusiast, Autotech has now come up with a dynamite new high-performance suspension package.
Most systems start with springs and shocks. The shocks chosen by Autotech are the new Tokico Illumina externally adjustable low-pressure gas shocks, widely regarded as one of the best shock absorbers available anywhere. The Illumina adjusts both for compression AND rebound, unlike other shocks that adjust to compensate for wear on the compression stroke only.
The springs are also brand new. Using the same high strength chrome-silicon spring wire found in the factory springs, Autotech wound their springs five percent stiffer at normal ride height, with stiffness increasing under compression. This progressive spring rate keeps the “street” ride tolerable while retaining the ability to provide some serious wheel control when it is needed in hard cornering.
Sway bars are usually next on the list for replacement or installation. Autotech’s front bar design incorporates urethane bushings and special exhaust clearance that make it a joy to work with. A 19 mm bar is available for Rabbits and a 22 mm bar is available for Golfs. The great stuff is found at the rear of the car, where Autotech fits a 25 mm bar for Rabbits or a 28 mm bar for Golfs. Autotech’s new rear sway bar utilizes sliding ends to allow it to work without fighting the rear torsion beam in spite of the differences in their pivot points.
As the rear torsion beam is twisted (as it would be in a turn) it pivots at a given centerline. Because it is impossible to mount the sway bar with the same centerline, all sway bars must have a different centerline than the rear torsion beam. When the body is level, it makes no difference that the ends of the sway bar are bolted fast to the ends of the torsion beam. When the torsion beam and the sway bar are twisted, however, the difference in pivot points means the sway bar tries to push (or pull, depending on whether the wheel deflection is up or down) the end of the torsion beam out of alignment.
Autotech found that by eliminating the rigid mount at the rear sway bar ends, they could eliminate undesirable geometry changes caused by sway bar binding. This not only sounds good in theory, it works in practice. After the bar has been working for a while, you can see that it moves just over half an inch between peak excursions. Of course, the rear bar rides in Autotech’s urethane bushings, too.
You probably remember that Autotech was the first firm to bring you triangulated stress bars. Now they are going one better with their new all-aluminum adjustable stress bars, designed to fit better and weigh less than conventional stress bars.
No one knows what the future will hold, especially with top-notch firms like Autotech competing to bring you the best products. No matter what the future brings, however, the current state-of-the-art in aftermarket VW suspension is going to be hard to beat. For more information, contact Autotech at 1800 North Glassell, Dept. VWP, Orange, California, 92665, telephone (714) 974-4600.
Visit AutoTech SportTuning on the web.