The rear suspension on ’84-’87 Fieros is not ideal—a condition called bumpsteer is to blame. Bumpsteer is a change in the toe setting (alignment) as the wheels move up and down. This condition is responsible for the twitchy handling you may have experienced during transition from a straight line into a corner, and it can be the reason for most high-speed instability problems. Zero bumpsteer is ideal.
In most cases, it is possible to improve the bump characteristics of a vehicle by moving the locations of the steering linkage pivot points and/or changing the lengths of the tie rods. The Fiero is essentially a mid-engine car with a front-wheel-drive unit mounted mid-ship. The steering knuckles from the front-drive vehicle are retained and are tied off to the frame (engine cradle) to eliminate the steering. Unfortunately, the steer effect is not fully eliminated and we are left with bumpsteer. Furthermore, modifying the tie rod mounting points and/or lengths will only help the situation within a certain range of the suspension travel, creating what might be called a sweet spot.
Most enthusiasts know that lowering the center of gravity by lowering their car will greatly improve handling. Many factors affect just how low is practical. Will you use the car primarily for racing, where performance is everything, tracks are as smooth as glass, and ground clearance need only be a couple of inches? Perhaps you want a certain stance where lowering the vehicle 1 inch or 1-½ inches is all that’s required. Are you building a kit car that requires a 3-inch drop just to make it look normal? As you can see, lowering a car means different things to different people.
In designing a bumpsteer fix, Held Motorsports thought it pointless to design a single sweet-spot bumpsteer fix when everyone’s sweet spot is in a different location. Its solution was to make changes to the geometry that totally eliminate bumpsteer through the entire range of suspension movement, making it universally applicable.
The Held Bump Stop Kit ($625) includes two control arms, two toe links, and two knuckle adapter brackets. The control arms come with urethane pivot bushings, sleeves, and weatherproof spherical bearings at the knuckle assembly. The kit allows the use of stock struts, and while the kit doesn’t require any frame modifications, welding, or other heavy mods to the car, the knuckle assembly does require some minor modifications (one hacksaw cut of 1-½-inch length). The steering arm taper is also drilled out using the fixture provided in the kit.
Using the Bump Stop kit allows installation of most aftermarket add-on sway bars, and it’s available in a wide-track version. The kit does not change the offset of the tires, either. Held’s kit also works in conjunction with its other suspension components (such as 13-inch brakes) and performance front-end suspension components to noticeably improve the ride of a Fiero.
Initial preparation for the installation involves removing and discarding the factory rear control arms and tie rod assemblies. It may not be necessary to remove the knuckle assembly from the strut in order to perform the conversion, but one may find it easier to work on the knuckle when it is off of the vehicle.
