We’re helping Justin Pawlak (JTP) build a street/drift Mustang, Project sidewayS197. This 2006 Mustang GT will be cursing the streets, and putting on some amazing drifting displays for fans. Drifting is a sport that involves controlling a car at its limits. This requires a suspension system that will allow JTP to maintain total control of his car as he showcases his incredible talents behind the wheel. Since this is a street car that JTP will drive regularly, he also needs a suspension system that won’t send him to the chiropractor’s office after every trip to the burger stand. To get the right S197 suspension, we turned to Whiteline for a complete solution.
The Right Parts
We look for flex, and areas where we need to improve tire contact area for maximum grip. -Tom Phan, Whiteline Marketing Director
Whiteline develops parts by looking at key areas that need to be addressed. Phan says that one of the first steps involved in developing a new part is to place cameras on a vehicle chassis and drive the car. “We look for flex, and areas where we need to improve tire contact area for maximum grip,” says Phan.
The goal with the front suspension is to update everything for the changes that have already been made to sidewayS197. JTP needs to be able to precisely guide the car in any maneuver during a drift demonstration. At the same time he doesn’t need the front suspension to be so brutal that the car is unpleasant to drive on city streets.
Whiteline sent us one of their front lower control arm to chassis braces, part number KSB726. This piece helps reduce flex in the front end, stabilizing alignment angles, and maintaining better front tire contact patch. It’s installed from the front sway bar mounting bracket, to the lower control arm mount.
Roll Center Kit
Roll center and Bumpsteer
Whiteline also includes one of their bumpsteer kits in this package. “As you correct roll center, bump steer gets worse, so you need a bump steer kit” says Phan. Bumpsteer occurs when a wheel raises, such as when in a cornering maneuver, or over changes in pavement. The toe angle of the front wheel changes, causing that wheel to steer. As a result the car is more difficult to control. In a best case scenario this just causes excessive tire wear. In a worst case, it causes the car to understeer. The tie rod ends that Whiteline provides allow for adjustment at the steering knuckle in order to compensate for the roll center correction and reduce or eliminate bumpsteer.
Since JTP’s car already sits lower than stock, we needed a way to correct the front roll center, getting suspension components back in line, and keeping the car handling properly. Whiteline sent us their complete roll center and bump steer correction kit, part number KCA306.
The first component of this kit is a set of new ball joints which will allow for roll center correction. The ball joints are actually adjustable with three positions:
- Position 1 Stock
- Position 2 Lowered one-inch
- Position 3 Lowered more than one inch.
The ball joints correct roll center by moving the steering knuckle up in its mounting position. This raises the front roll center which Phan says improves cornering through better roll resistance and a reduction in suspension compression in hard cornering.
Control Arm Bushings
It used to be that enthusiasts just replaced their front control arms to correct front end issues, and repair worn parts. Those changes are expensive, and not always practical. In the case of sidewayS197 we chose to use Whiteline’s front control arm bushing kit, part number KCA433. This kit will improve anti-dive, camber, and steering feel. The kit gives a camber change of 0.75 degrees. It also improves anti-dive under hard braking.
The tail is what hangs out and puts on the biggest part of the show in a drift car. Maintaining control of the posterior of sidewayS197 is also critical to executing all track maneuvers with precision. Whiteline hooked this project up with everything to make the car turn like it’s on rails, and allow JTP to keep the back end exactly where he wants it when he lights up the tires.
Whiteline constructs their rear upper and lower control arms from 4130 chromoly steel for lightweight and strength. S197 Mustangs from wheel hop when the rear tires get loose, especially when you start adding power. Phan says, this is one of the areas where Whiteline focused their efforts in designing the lower control arms.
Part number KTA140, is designed using Whiteline’s polyurethane bushings to reduce bind and flex which are the key cause of wheel hop. The arms also have adjustable ends to aide in pinion angle correction and wheel alignment.
The upper control arm, part number KTA141A, is also constructed from chromoly steel and is a one piece design for improved strength and includes a new upper mount as well. This UCA is more than a direct replacement, it features an innovative idea that allows it to be adjustable without putting a rod end in the control arm tube. The crush sleeve inside the upper portion of the mount is an eccentric. According to Phan this allows the pinion angle to be adjusted across a range of the few degrees necessary for most enthusiasts. The polyurethane bushing are also more resistant to flexing and binding, and won’t transmit excessive levels of noise and vibration through the chassis.
Ford made some great strides in Mustang suspension design when they adopted the Panhard bar in 2005 as part of the S197 suspension. While this is a step in the right direction, it still has some disadvantages on the track. “A Panhard bar can’t be tuned for both sides of the car,” says Phan, “You can tune it for right turns or left turns, but not both.” Keeping the rear of the car predictable, and stable in a drifting maneuver is key to the safety of the maneuver and pulling it off correctly.
The solution here is a Watts-Link, Whiteline part number KDT916. The Watts-Link completely replaces the Panhard bar, and works in conjunction with the other Whiteline parts already installed. This design transfers lateral cornering loads evenly from side to side, resulting in smoother, flatter, and faster cornering and better control of the rear of the car. The Whiteline Watts-Link is made from 4130 chromoly and is a unique design that’s completely bolt-on.
The centerpiece of the Whiteline Watts-Link is a high performance differential cover. This cover is reinforced and uses a center bolt pivot welded to a six-point spider brace to spread out the load on the pivot and prevent it from shearing. It’s also adjustable at the side links. The roll center is adjustable with the two mounting positions for the rear pivot, for 1/2-inch or 1 1/2-inch lowered ride heights.
All of the parts Whiteline sent us for this installation were bolt-in ready, requiring no special tools to get them in place. We’ve outlined the highlights of this installation in the photos and captions here. Once everything is installed, the car must be set at ride height and the pinion angle adjusted properly using the eccentric in the upper control arm bushing and the adjustments on the lower control arms.
With pinion angle set, the Watts-Link can then be set properly. This needs to be done to ensure the rear axle is properly centered by the links. Whiteline says to measure from each wheel to the framerails and then adjust the links to get the rear axle centered. Once everything is centered, the jam nuts need to be tightened and the use of a thread locking compound is advised to keep the links from loosening.
On the street, the car retains comfortable ride quality, without pounding the driver to death, or driving him crazy with excessive noise. The differences in the car’s handling was apparent the first time JTP hit a fast corner, and we can’t wait to see him step the car’s tail out and light the rears up in a cloud of smoke.