It seems that today's cars have more soften-the-ride suspension bushings than we can even count. What's even more surprising is how poorly these bushings actually perform when it comes to handling. Thankfully, there are companies like Pedders who identify the shortcomings these late-model cars suffer from and provide solutions for nearly every rubber piece on the car. They call it "Pedderising" and we call it "required."
If you don't know by now, the LX platform uses many parts from Mercedes-Benz. It incorporates the W220 control arm front suspension from the old S-Class and the five-link rear suspension from the old E-Class, in addition to several other foreign parts, but we're here to focus on the suspension components.
It's because of this sharing with Benz's roots that we have a sophisticated, affordable rear-wheel-drive luxury sedan from Chrysler. But, it's also because of these roots that we have some room for improvement in the performance department. The Mercedes parts are designed to be comfortable, which means they were made with a lot of "play" in them. The entire rear assembly from the E-Class moves around considerably under acceleration in stock trim. Now imagine how much it moves around when you've installed a few aftermarket parts on it, and the Hemi is pushing more torque towards it.
This is where Pedders steps in. According to Pedders, just driving your stock LX car in a performance manner will wear these bushings at an accelerated rate, the results being reduced tire life and poor handling.
Up front, Pedders has come up with a correction for the front control arms' reputation for bumpsteer. Engineers say that the factory LX front suspension will alter toe as much as 15 mm under load, causing the tires to "scrub" and the steering to become less responsive. In some cases, the car will actually steer into a different direction because of the bumpsteer being so severe. The Pedders Bumpsteer Correction Kit claims it will reduce the tendency for toe-in and toe-out changes to within 3 mm. Additionally, front lower-strut mounts, front/rear radius rod bushings, and lower control arm bushings help to provide consistent suspension geometry under cornering, acceleration, and braking. According to Rich DeCrane at Precision, "The factory rubber bushings are weak, and will cause your alignment to fade over time. The Pedders bushings also allow a wider range of camber, so that you can dial in your alignment to suit anything from everyday driving to aggressive road race conditions."
The rear cradle certainly isn't forgotten, either. Pedders offers a rear camber-adjustable bushing since the factory bushings don't allow any adjustment-required for cars that are lowered-and the full gamut of control arm and rear cradle bushings to minimize cradle deflection. According to Pedders, even under normal driving conditions, the factory cradle will move from side to side, as well as fore and aft. This makes the car feel sloppy in corners, and once you feel a "Pedderised" car you'll know what you're missing. It also gets rid of the differential-killing wheel hop.
Last, but not least, the parts that steal the show are the Pedders Extreme XA adjustable coilover shocks for the front and rear. These shocks are 30-way adjustable, and unlike other shocks, you adjust the height by turning the body of the coilover and not the spring. This keeps the spring at its preload and doesn't compress it further to make ride height adjustments.
|160059||Pedders Extreme XA Adjustable Coilover Kit|
|EP2113||Bumpsteer Correction Kit (Front)|
|EP4107||Front Lower Strut Mount (Front)|
|EP6567||Front Radius Rod Bushes (Front)|
|EP7276||Rear Radius Rod Bushes (Front)|
|EP6568||Front Lower Control Arm Bushes (Front)|
|EP6570||Front Upper Control Arm Bushes Adjustable Camber (Front)|
|EP7277||Rear Camber Link Adjustable Bush Kit (Rear)|
|EP1172||Rear Cradle Bushes (Rear)|
Precision Motorsports gave us their alignment specs provided by Pedders to help them get the most out of the new products. These settings are a starting point to give car and shop owners an idea of where their alignment should be set. These are just ballpark numbers.
|Full Road Race|
|Full Drag Race|
Total toe is 0.20 degrees and thrust is set to 0 for all of the Pedders alignment specs.
Here's every bushing that...
Here's every bushing that Precision Motorsports of Florida will be installing on the SRT8 300C. Each of these bushings will help minimize deflection of the parts and will increase performance and durability of the suspension components.
First on the agenda was to...
First on the agenda was to see where this previously lowered SRT8's ride height was sitting.
This 300 already had Pedders...
This 300 already had Pedders springs and shocks but the owner wanted to correct the shortcomings in the factory suspension while upgrading to the adjustable Xa Coilovers.
Scott Seifreit and Larry Neville...
Scott Seifreit and Larry Neville start things off by removing the exhaust system to gain access to the rear cradle. The brake lines were then removed because the cradle must be lowered away from the car to remove the rear cradle bushings. This also makes the control arm bushings easier to access.
The staff of Precision Motorsports...
The staff of Precision Motorsports designed this "homemade" cradle support in-house. It's fixed to a transmission jack and perfectly holds and supports the rear suspension cradle while it's being removed.
With the cradle support in...
With the cradle support in place, the bolts are removed and the shocks are loosened from the body, and then the guys removed the rear cradle and transported it to an open area.
Removing the factory bushings...
Removing the factory bushings will require some grinder work.
Once the cradle bushing was...
Once the cradle bushing was treated to a few sessions of the cutoff wheel, it was ready to be removed by yet another in-house tool.
The end result is this destroyed...
The end result is this destroyed bushing. "They were designed to wear out, but they weren't exactly made to be removed very easily," joked Scott.
The remaining bushings are...
The remaining bushings are simple to replace. The crew takes out the rear control arms to replace the eight bushings housed in the four control arms.
They are easily removed on...
They are easily removed on a press.
Here's the camber-adjustable...
Here's the camber-adjustable bushing that will be installed loosely in a temporary position before being taken to the alignment rack for the final camber to be set. Notice the offset metal insert inside.
The new Pedders cradle bushings...
The new Pedders cradle bushings literally slide in and the cradle is ready to be raised back into the car. The shocks are attached to the cradle before being raised to make installation easier.
These spring-perch adjusters...
These spring-perch adjusters will determine the car's ride height and are hung on the body before the cradle is lifted back in place. This is a remote-perch coilover. Some coilover systems feature the spring over the shock body in the rear like the front, but it's usually not used in the rear because of the vehicle's design.
They put the cradle back in...
They put the cradle back in using the transmission jack, and bolt everything down and reinstall the brake lines.
With the back of the car taken...
With the back of the car taken care of, it's on to the front. The front of this 300 uses Bilstein struts with Pedders springs.
These radius rod and control...
These radius rod and control arm bushings are easily....
.....pressed out, and the...
.....pressed out, and the new red Pedders bushings pressed in.
The Xa coilover is raised...
The Xa coilover is raised to the body with the strut mount attached, and the upper control arms were pressed in off the car.
To make rear suspension adjustments...
To make rear suspension adjustments easier, Pedders includes these remote adjusters that place the top shock adjuster within easy reach with the trunk open. The fronts are easily adjusted by popping the hood and turning the tops that are clearly marked with +/-.
Once all the new parts were...
Once all the new parts were installed, the SRT8 was taken over to the alignment rack to receive an aggressive street alignment. According to Precision, they set their alignments one of four different ways. See the sidebar for the alignment specs.