Now that Ford’s latest pony has been out on the street for a few years, it’s no secret that the 2015-plus Mustang is a big step forward from its predecessor in terms of its drivability and handling characteristics. The transition over to an independent rear suspension setup as standard equipment plays no small part in that equation.

The most unique feature on our coilovers is that they are the only 6061-T6 Aluminum Macpherson struts on the market for the S550 Mustang. — Mark Rossetti, aFe

But as a mass market vehicle, Ford is saddled with the responsibility of tuning the car to appeal to the widest range of buyers (and driving skill levels), which means there’s plenty of room for improvement for those looking to bolster their car’s handling prowess. Fortunately for Mustang owners, they enjoy not only available upgrades from the Ford Performance division, but robust aftermarket support as well, making the choices for an upgrade path plentiful.

Among those choices are the offerings from Advanced Flow Engineering for S550s. More specifically, our focus will be on its coilover shock (PN 430-301001-N) and spring (PN 410-301001-N) combination as well as front and rear anti-sway bars (PN 440-301001-N).

aFe’s S550 project car is all decked out in a company livery. With the suspension setup, it also walks the walk with stellar handling to go with the looks. (Photo Credit: aFe, Sinister Mustang)

The company also offers all three components as one comprehensive suspension upgrade for S550s as the Control Series Stage 2 Suspension Package. In addition to getting some details about the parts, we also stopped in at the company headquarters to highlight installation of the sway bars and coilovers.


Features and Benefits

Here’s a look at the aFe coilover setup for front and rear versus their stock counterparts.

aFe Control Series Stage 2 Suspension Package

  • Featherlight coilovers are fully ride height adjustable
  • Adjustable damping with 24 distinct settings on the front and rear
  • The inverted mono-tube design is extremely stiff and is designed to carry high cornering loads without deflection and binding like traditional struts
  • Lightweight, Hard Anodized 6061-T6 Aluminum bodies yield high strength, while still maintaining a lightweight design
  • CNC Bent, Lightweight Tubular Alloy Steel Sway Bars 35mm 2-way adjustable front, 32mm 3-way adjustable rear with precision CNC Machined, TIG Welded Bar Ends
  • Includes Polyurethane Bushings and CNC Machined 6061-T6 Aluminum Brackets
  • PN 520-301001-N
“The most unique feature on our coilovers is that they are the only 6061-T6 Aluminum Macpherson struts on the market for the S550 Mustang,” says Mark Rossetti of aFe. “This creates a lightweight housing, and uses a 36mm, inverted monotube strut to minimize deflection during high cornering and braking loads.”

These lightweight coilvers are fully ride height adjustable, and feature adjustable damping as well, offering no less than 24 distinct settings on the front and rear, and feature an easy to use rotary knob which adjusts both compression and rebound in one device.

Unlike traditional struts, which can suffer from deflection and binding under high lateral loads (like those you’d experience during high-speed cornering on track), aFe’s inverted mono-tube design is extremely stiff, and that added rigidity serves to combat those unwanted characteristics. The inverted mono-tube construction utilizes a floating piston to separate the oil and nitrogen gas, allowing for predictable handling and a consistent feel.

With such a wide variety of settings, owners can fine-tune the damping characteristics to find a happy balance between ride compliance and on-track prowess, or simply make adjustments as needed when heading to the track or for daily driving duty. aFe’s coilovers are hard anodized and assembled in their Corona, California, production facility. “Due to the aggressive spring rates, these coilovers are geared most toward enthusiasts who need track-level capability,” Mark explained. The anti-sway bars offer a wider scope of applications though. The bars are both street-and track-friendly, as they have less of an effect on overall ride compliance.”


A look at the aFe front sway bar versus the stock piece (left). On both the front and rear bars, the furthest inbound end-link connector will yield the stiffest behavior. Alternatively, the furthest outward setting will provide the softest setting. For the rear bar, AFE recommends starting with the intermediate setting, which is the center hole (right).

Those bars are made from CNC-bent, lightweight, tubular alloy steel and measure 35mm up front and 32mm in the rear. Additionally, the CNC machined, TIG-welded bar ends offer two-way adjustability at the front end and three-way adjustment at the rear, allowing drivers to fine-tune the suspension setup to their driving style and preference in terms of oversteer, neutrality, and understeer characteristics. These bars include polyurethane bushings for added deflection resistance and CNC machined 6061-T6 aluminum brackets.

“The package is designed as a direct-fit application and requires no modifications to the vehicle,” Mark said.

Installation Highlights

aFe estimates that the entire procedure can be done in about four hours, and they recommend the use of a lift (if available), due to the fact that some of the exhaust system hangers must be unbolted and the exhaust system supported independently in order to access the lower A-arm bolts.

You’re also going to need a spring compressor in order to remove the strut center bolt from the stock strut, as it will be re-used on the coilovers, so that’s worth keeping in mind as well.

Once the car is up in the air and the wheels have been taken off, you’ll have the access required to get started, which gets underway by unbolting the sway bar end links from the stock struts.

As you work your way through the installation process, aFe also recommends taking photos along the way so that you can quickly recall how it all comes back together, and definitely be sure to follow the installation guide’s recommendations for each bolt’s torque spec.


The front coilover install had already been performed before we arrived on-scene, but aFe provides a detailed installation guide that spells out the process step by step. With the front end already handled, we moved to the rear suspension. The stock rear springs are removed from the car to be replaced by the coilover setup, which incorporates its own springs. Springs are no longer located in the stock location when converting to a coilover setup.


Removing the stock rear shock and replacing it with the aFe shock-and-spring coilover combination is relatively easy. Two bolts up top and two at the bottom, allow removal of the stock shock. The aFe coilover installs right in its place with the car’s original mounting hardware.

The bottom of the coilover is secured to the car’s IRS rear lower control arm as shown.

Moving on to the sway bar installation, we started at the front of the car at the passenger side. To improve access, turn the steering wheel all the way clockwise as if making a right-hand turn. This can also be done by grabbing the sides of the rotor with both hands while simultaneously pushing with one arm and pulling with the other, if you’d prefer not to grapple with the steering wheel while the car is on the lift.

Beginning with removing the stock front bar, on the passenger side, it’s easiest to access the mounting hardware from under the hood with a long extension for socket. When the four bolts are removed, and end links are disconnected, the bar is removed from the passenger side of the car.

Beginning with removing the stock front bar, on the passenger side, it’s easiest to access the mounting hardware from under the hood with a long extension. When the four bolts are removed, and endlinks are disconnected, the bar is removed from the passenger side of the car.

Install the mounting blocks per aFe’s instructions and secure the new bar in place with the stock bar’s original hardware. Below you can see the block and hardware in place from both sides of the car and from under the hood on the driver side.

Here you can see the block and hardware in place from the side of the car (upper left) and from under the hood on the driver side (upper right). The ends of the bar attach to the car using all the stock hardware and endlinks (lower left, lower right).

Next we moved on to the rear sway bar. Removing the rear bar only takes a few minutes by unbolting the four mounting bolts and the two end links.

Attach the mounting blocks to the new bar. Tighten the mounting block bolts and secure the endlinks, again with the car’s original hardware.

AFE supplies an additional nut to secure the brake line to the AFE bar in a similar fashion to the factory setup with the stock bar.


The kit includes a thin hex nut to secure the brake line bracket to the end of the endlink stud. Use a 19mm wrench or socket and torque this nut to 40 lb-ft.

Of course this abbreviated walk-through simply highlights some of the finer points of the installation, so be sure to have aFe’s detailed instructions handy when you embark on this install to ensure that you don’t overlook anything along the way.

Want to take the handling of your S550 to the next level? aFe’s Control Series Stage 2 Suspension Package offers an all-in-one solution for Mustang owners who need track-level handling capability and demand the fine-tuning capability that coilovers, adjustable dampers, and adjustable-endlink sway bars provide. Give ’em a shout and see what they can do for your ride.