After lowering the ride height...
After lowering the ride height of our '09 Dodge Challenger, we wanted to correct for bumpsteer so we ordered this kit from Razors Edge Motorsports.
The term bumpsteer is often used, sometimes misused, and seldom properly understood by most auto enthusiasts. Despite the name, bumpsteer doesn't have anything to do with steering wheel input at all, but rather suspension geometry. Defined as a change in toe angle caused by the suspension moving up and down, bumpsteer can be caused by many sources including body roll, brake-dive, or simply hitting a bump in the road (hence the name bumpsteer). Correcting for bumpsteer in your new Charger, Challenger, 300, or Magnum requires double-adjustable outer tie rod ends, and we found the parts we needed for our '09 Challenger R/T in a kit from Razors Edge Motorsports.
Before we correct for bumpsteer we must first understand it, which begins by understanding that a car's front wheels don't move up and down in a straight line as the suspension travels, but rather in an arc. So at ride height, the track width of the wheels is at its maximum (or close), and as the suspension travels up or down, the track width of the front wheels narrows. Just as the suspension travels in an arc, so do the tie rods that connect the steering rack to the wheels, via the spindles. If the arc that the tie rods follow is not the same as the arc the wheels follow, the tie rod will push or pull the wheel to a toed-out, or toed-in position, creating bumpsteer.
While it is nearly impossible to eliminate bumpsteer throughout the range of suspension travel, auto manufacturers like Dodge try to minimize bumpsteer within the range of normal suspension travel at factory ride height. Since our Challenger is a good two inches lower than factory, we're out of the range of acceptable bumpsteer and need to correct our car's suspension geometry. Fortunately, Razors Edge Motorsports has a bumpsteer kit that corrects for this problem with height-adjustable outer tie-rod ends, and can even reduce bumpsteer in new Mopar iron at the factory ride height. Since installing these parts does require the car to be aligned, we contacted neighboring shop Inline Performance to assist with the installation. With their help (and lift), we had these parts installed in a couple of hours, and the car properly aligned, virtually eliminating bumpsteer at our lower ride height.
The factory tie-rod end is...
The factory tie-rod end is designed for proper suspension geometry at factory ride height, but is not ideal for a car that's been lowered or with modified suspension. The only way to correct this is to go with an aftermarket adjustable outer tie-rod end like the ones we found in a kit from Razors Edge Motorsports.
Removing the factory tie-rod...
Removing the factory tie-rod end is easy. Simply break the jam nut and the retaining nut loose, and then gently tap on the spindle and the tie-rod end will break loose. Be sure to take a measurement so you can get the tie-rod length close with the new parts installed. They're a different length so counting the threads won't work.
With the factory outer tie...
With the factory outer tie rod out of the way, the billet aluminum Razors Edge piece can be installed. Unlike the stock unit, the new outer tie-rod end is threaded on each end, making individual toe settings easy.
The real advantage of these...
The real advantage of these tie-rod ends, and the one that helps eliminate bumpsteer, is the height adjustability where the tie rod meets the spindle. By varying the placement of the shims included with the kit, suspension geometry can be greatly improved at any ride height.
As a baseline, try to shim...
As a baseline, try to shim the tie rod so that it's parallel with the control arm. With the car on the alignment rack, toe can now be set. Checking bumpsteer involves moving the car up and down and noting the change in tow.
Through trial and error, we...
Through trial and error, we swapped shims around until bumpsteer was virtually nil in the normal range of our suspension travel. This is a well-engineered kit that's easy to install, correcting a common problem with new Mopar suspensions.