There are several aftermarket suspension systems available for the S550 Mustang, but one brand that is stepping up in the ranks is Pedders Suspension. For the past 68 years, it’s been specializing in the road-racing scene in Australia, but recently the brand is breaking into the North American marketplace by offering high-quality, street-ready suspension systems at a competitive price point.

Overall, I wanted to compare the Pedders eXtreme XA Coilover Kit (P/N PED-162099, $1,399.95) against the factory Ford Performance suspension that was already installed on a 2017 S550 Mustang to see what difference it can make for the average weekend warrior, such as myself.

Mustang S550 Pedders Coilover Suspension Review

Ariah and I, at our “Top Secret Facility” otherwise known as Gateway Motorsports Park, in Madison, Illinois, with the test S550 Mustang GT in the background.

“Pedders’ eXtreme XA Coilover Kit was designed with street performance in mind,” says Marty Staggs of Pedders USA. “This kit is for the weekend warrior who wants better handling during spirited driving or occasional track days, while still keeping the car a pleasure to drive in normal daily situations. It is a firmer-than-stock setup, but not harsh. Because they are not a full-on race setup, you can put them on your daily driver and have some fun, but not beat yourself to death on a daily basis.”

I needed help, so I grabbed media journalist and professional flat-track racer, Ariah Richardson. Together, we set up a test based on how fast I could run the Mustang through a 300-foot, 5-point slalom, both before and after the Pedders kit was installed. To keep the playing field even for the test, we kept all parameters the same outside of the suspension (and the slight adjustment in ride height). The Mustang was outfitted with the stock Pirelli P-Zero tires — 255/40R19 front and 275/40R19 rear — with 38 pounds of pressure all the way around. Luckily, even the weather conditions were the same for both tests.

Not only would this give us a feeling of the difference the Pedders system can make, but also how difficult the installation process would be, and the value of the options on the kit. After a few phone calls, logistics planning, and several pots of coffee, we landed ourselves in the parking lot of the Gateway Motorsports Park facility just outside of Saint Louis, Missouri, for our first test in stock trim.


Test #1 (Stock)
Jogging the steering wheel of the Mustang through the cones, the factory Track Handling Pack handled fairly well. After a few initial practice passes, Ariah recorded my first official run at 9.13 seconds. Next, she recorded my best run at 9.00-seconds flat, followed by a 9.08-second pass on the third and final run.

Test on the Mustang factory suspension

Pushing the Mustang around the last cone of the 300-foot, 5-point slalom course, Ariah is capturing my run during the test on the factory suspension.

Overall, I felt as if the performance of the stock suspension was great but it was a little spongy, with body roll causing the car to “hike up” and wanting to lose grip, forcing me to shimmy around the last few cones. Out of the gate, it’s not a bad option for normal and spirited road driving — I obviously wanted more, so off to the garage we went to install the Pedders kit.

This kit is for the weekend warrior who wants better handling during spirited driving or occasional track days, while still keeping the car a pleasure to drive in normal situations. — Marty Staggs, Pedders USA

The Installation
The system we installed was the Pedders eXtreme XA Coilover kit, which includes the SportsRyder adjustable coilover front struts and rear coil springs and shocks, along with a shorter front sway-bar end-link kit to accommodate lowering the vehicle. Additionally, I got the matching adjustable front camber plates (Pedders also sells the “Plus” kit, which includes everything already assembled).

As you can see, there are a lot of features in the adjustment area. The SportsRyder dampers have been refined through the decades to allow for tunable damping (compression and rebound together), while the coil springs are tuned specifically for each application. The camber plates provide full camber adjustability. Altogether, the system allows the user to adjust coil preload, front ride-height, rear ride-height, and camber while still maintaining an acceptable ride quality.

Peddlers adjustable camber plates

The Pedders Extreme XA front coilover is shown here with the matching adjustable camber plates.

One feature the Pedders kit includes — which many other brands in its price range do not — is the 30-way-adjustable front strut and rear shock damping. This is a huge win, especially if you’re planning on driving your car on the street on a regular basis. Additionally, there are very few, if any, other companies that offer the parts in a complete kit already assembled.

Overall, the kit took just under four hours to install. I can’t say the process went completely smooth, being there were limited installation instruction resources. We also needed to research correct preload adjustments and other small details, which might cause a head scratch for someone performing the installation themselves at home.

Although, if you find yourself in this situation, Pedders USA is on tap as a full technical resource, but Ariah and I wanted to see if we could tackle it ourselves and eventually succeeded with the installation.

Pedders coilover suspension installation

Ariah and I installing the front struts of the Pedders coilover system. Overall, the entire installation took just under four hours to complete.

The last steps of our install were setting the ride height and damping, which we both wanted to keep the car somewhat close to the stock kit for our test. So, we only lowered the front by 3/4-inch and the rear by 1/2-inch, then we set the damping to 8 clicks back from the fully firm 30, which Pedders says compares in ride quality to the stock setup. Keep in mind, this kit can allow the car to be lowered nearly 3 inches and turned up to a full 30-clicks, so there is plenty of adjustability built in.


Test #2 (Pedders)
After an alignment and camber check from the local Ford dealership, we finally made it back to the facility for our second test. I began by warming up the car with a practice run, and out of the gate broke my previous best time with an 8.35-second pass. The car was tight! I was actually blown away by how sharp it felt running through the cones, and Ariah recorded my first official test pass at 8.25 seconds. I followed that up with an 8.18, then the third (and fastest) pass of 8.13 seconds.

Slalom test Ford Mustang GT

Ariah capturing time, as I push the Mustang GT through the last cone during the second slalom test.

The car was now firm and extremely tight. The dipping in the rear and shimmying around the cones was no longer an issue, and I didn’t need to pull out of the gas pedal as hard when switching back through the cones. I could also feel a lot more feedback through the chassis and steering, making my actions more fluid when jogging the wheel back and forth.


A New Believer
In my experience in the past with coilover kits, they can be loud and clunky — a sacrifice for performance. But, both Ariah and I were surprised with how quiet and docile the Pedders system is. Even at the damping setting we had the car on (8-clicks from fully firm), we couldn’t get over how quiet and smooth the Mustang was while we were driving to the dealership and the test facility — as if riding in a factory set up.

Pedders Coilover Extreme XA Mustang GT

Here the Mustang GT sits in full stance with the Pedders coilover kit installed. The front is lowered by 3/4-inch, with the rear at 1/2-inch lowered.

Overall, for the investment, no Mustang S550 owner can go wrong with this choice. Even though our test wasn’t on a full-sized road course with physicists and high-tech measuring instruments, it was enough to make us both believers that you can have a proven performance suspension at an affordable cost – without being punished for it. Now that the suspension has been on the car for a while, I love the way it feels. I can’t wait to get it on the track and start playing with the adjustability of this system to see what it can really do. The beauty is I can return it right back to the way I have it now.