Improving a Pony Car’s Handling


Koni Yellows

Fresh off the FedEX truck! Gosh, I love it when FedEX trucks deliver car parts!

Koni Sport shocks (known colloquially as “Yellows”) are OEM replacement shocks that have a valve on the top for adjusting the rebound stiffness. This enables basic tuning of handling. Specifically, increasing the rebound on the rear shocks decreases understeer later in the turn. That’s exactly what I needed! The shock bodies are also slightly shorter, allowing full range of motion on lowered cars.

Of course, shocks alone do nothing for body roll. I need stiffer springs for that. Unfortunately, most “lowering springs” suck. They lower the car, which does lower its center of gravity, but they often aren’t stiff enough to counteract the shorter suspension travel, causing bottoming out under hard cornering. Fortunately, Steeda makes some good “lowering springs” that are actually stiff enough to make up for the lost 1.5 inches of suspension travel. They’re called “Ultralites,” and they’re bright blue.


Steeda Ultralites

Getting a little ahead of ourselves here, but these are the springs installed on the front Konis. Also, whoever called the springs “Ultralites” needs to communicate with whoever stenciled “Superlite” on the actual spring.

Lowering a McPherson strut car increases negative camber. The Mustang’s factory camber adjustment is not quite adequate to correct this camber change, so I needed to get some camber plates. Maximum Motorsports road races Mustangs and makes some pretty trick pieces to improve their handling. As an added bonus, these camber plates allow an additional half degree of caster, which increases negative camber under cornering while leaving the straight-line camber the same.


These plates reuse portions of the factory mount to help keep NVH to a minimum.

Now that my plan for the front suspension was squared away, I needed one for the rear. The solid rear axle on the Mustang uses a panhard bar to locate it laterally. This causes the rear axle to move in a bit of an arc and shift laterally relative to the body. Lowering the car will cause the axle to be un-centered when simply sitting there. While eliminating the panhard bar system is something I’ll be doing eventually, I needed a solution to re-center the axle for now. I picked up an Edelbrock adjustable-length panhard rod to enable me to re-center my rear axle. I also got an Evolution Performance panhard brace to provide some more stiffness to the rear of the chassis.


Simplified diagram of a panhard bar system. As the suspension moves up, the axle rotates about the upper right pivot point, causing it to shift slightly to the left relative to the body.


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