Ford engineers hit a home run with the suspension under the 2015+ Mustang. Delivering a far higher level of performance and ride quality in a Mustang than ever before, the S550 platform’s double-ball joint front suspension and an independent rear suspension do have some limitations, especially in higher-horsepower applications.
After the bushings were installed, the car felt planted. — Pete Williamsen, Energy Suspension
Fortunately, there are aftermarket solutions like the poly bushing upgrades from Energy Suspension. Longtime experts in the bushing upgrade game; the company put together a complete suspension upgrade for the latest Mustangs to address some of those suspension shortcomings.
“There are two major weaknesses of the factory bushings in the S550 platform that effect performance, most of it has to do with concessions made for noise cancellation and vibration dampening. The factory bushings are made of rubber which has the advantage of being maintenance free and quiet, as well as being superb at eating up vibration and road noise, but this is always at the expense of durability, handling, power transfer and predictability,” Pete Williamsen, Marketing Director at Energy Suspension, said. “In the S550 Mustang the major issue right out of the box is wheel hop and issues with alignment in the rear under hard acceleration, this applies to all Mustangs no matter how many cylinders or trim level, but becomes amplified when you add horsepower, creating some substantial launch and control issues in higher horsepower cars.”
Since the factory engineers have to account for a wide range of customers with varying levels of ride-quality expectations, some compromises must be made. As such, the factory bushings tend to be soft to neutralize the noise, vibration, and harshness characteristics that the suspension can communicate through the chassis.
“Energy Suspension fine-tunes the bushing material and shape to provide improved handling and power transfer. Energy’s Hyper-Flex Polyurethane has characteristics that tend to translate into more precise handling because of the faster rate that it snaps back from being deformed. Often (but not always) the material is made of a higher-durometer (firmness) than the factory bushing,” Pete says. “Often factory bushings have large voids to make them more compliant. Energy usually eliminates those voids to help keep your driveline in place. Our goal is to eliminate power robbing drivetrain movement and unwanted suspension movement without creating a firm ride or unwanted vibration. The factory S550 Mustang’s rear control arms move in unwanted ways under load, putting the force of the power applied in the wrong places, which is why there are such prominent wheel hop and control issues with the platform. The rear diff also moves a lot during hard acceleration, eating up throttle response and power.”
An ideal candidate for this increased level of control was the 600-horsepower ROUSH Mustang that traveled to the Power Automedia shop for a bushing swap.
“This is an involved job, although not terribly technically challenging. The removal and manipulation of the rear subframe lends itself to a challenging DIY installation,” Pete said. “If you have the proper tools, experience, patience and space it is doable at home, although we recommend it being left to the professionals. Definitely plan ahead and make sure you are equipped if you are going to take this on in your garage.”
Dropping the rearend and pulling the front control arms to remove and replace the bushings is a serious commitment, but given the minimal hardware change, the change is beneficial.
“There is a huge and immediate difference during acceleration. The Energy Suspension subframe, differential and control arm bushings work together to eliminate wheel hop and alignment issues during launch,” Pete said. “Launches and acceleration and more immediate and responsive. This particular application benefits from taught handling all around, especially when combined with the engine vehicle Hyper-Flex system. A factory car feels ‘ready’ for windy roads and track excursions with no other suspension mods. The difference is akin to performance suspension upgrade. The results are quite dramatic on this car.”
While you are going to feel the road imperfections communicated more clearly through the suspension with the new bushings, minimizing harshness is something the company strives to minimize.
“Like all performance upgrades, there is always a compromise,” Pete said. “One thing Energy Suspension works very hard to do is make sure any degradation is kept to a minimum while still providing that increased performance the customer is looking for. We fine-tune our products to be at home on the daily driver as well as the track.”
In the end, the upgrades fully detailed in the video above delivered a far more confident driving experience from a car with impressive performance credentials.
“This car has well over 600 horsepower on tap, and even with upgraded tires had some serious issues hooking up with the factory suspension. Handling was manageable and the ride was good, but there was a feeling that you were pushing the car hard on the corners, and application of throttle led to unpredictable loss of control,” Pete enthused. “After the bushings were installed, the car felt planted. With this much horsepower, you’ll always be able to lose traction at will, but it became much more predictable. Launches were much harder, and handling was much improved and made much more predictable. We didn’t have a chance to push to the limit, but the limit is much further out than it was from the factory. The best way to describe the car after the Energy Suspension bushings were installed was, ‘taught and ready.’”
For more on the Energy Suspension 2015+ Mustang upgrades, you can visit the company’s official site right here.
Energy Suspension S550 Upgrade Parts
• Front Control Arm Bushing Set (PN 4.3170)
• Rear Control Arm Bushing Set (PN 4.3166)
• Front Sway Bar Bushing Set (PN 4.5200)
• Rear Sway Bar Bushing Set (PN 4.5198)
• Rear Differential Mounts (PN 4.1139)
• Subframe Mount Set (PN 4.4122)