Chances are pretty good if you’re here reading the hardcore tech content on Stang TV that you aren’t just a casual Mustang owner, but rather, a Mustang enthusiast that bleeds blue and craves exhilarating performance. You’ve probably done at least a handful of the common bolt-on’s such as headers, mufflers, and a cold air intakes, and the like. And why not? The S197 platform literally begs for modifications and has an entire industry offering performance aftermarket parts based around it.

OEM suspension components, even on vehicles that are solely designed for performance and handling such as the Mustang GT are commonly less than stellar in their design and function. Or at least relative to the aftermarket options out there. Sure, it does the job if you’re just putting around town, but we aren’t here to do that. Our Kona Blue 2010 Mustang GT sports a well-rounded assortment of performance goodies that make the drive to the grocery store an exhilarating one, highlighted by a complete, intercooled turbocharger kit from John Urist at Hellion Turbo Systems that provides a stout 440 horsepower at the wheels, along with a Hushpower axle-back exhaust system.

While it’s true the drivetrain and the running gear of a vehicle go hand-in-hand, for this piece, we’re going to focus on the latter. Out GT has already been outfitted with a  sharp set of Rocket Racing’s chrome “Rocket Booster” wheels, measuring 20×9 with a 30mm offset up front and 20×10 in the rear with a 40mm offset. These wheels are specifically designed for late model muscle cars like our Mustang and sport a classic 5-spoke layout with modern features and design elements. These bad boys are then wrapped in a set of BFGoodrich’s g-Force T/A KDW tires that utilize a stiff sidewall design that utilizes a rubber compound in the bead area to deliver a higher degree of lateral firmness for a more precise feel than your standard tire and excellent cornering stiffness and power. Just what the doctor ordered. Our list of modifications is rounded out by a set of Disc Brakes Australia’s 5000-Series brake rotors for ample stopping power.

As anyone that’s driven a new-age Mustang can attest, while they do come right from the factory with acceptable handling abilities, they still exhibit some overall sloppiness, with excessive swaying and body roll when cornering and an equal level of brake drive. Sure, we could’ve lived with the factory suspension, but when direct factory replacement kits on the market make upgrading a snap, there’s simply no reason not to. Our Mustang was just begging for a suspension upgrade that would take full advantage of the ponies under the hood and our other performance upgrades and provide that nice, smooth ride under cornering, braking and, ahem…excessive acceleration. And so we turned to the the folks at Bilstein and their BTS front and rear suspension kit that’s not only affordable, but a true bolt-on upgrade that won’t cause your hairs to turn gray to install. Read on to learn more.

Our 2010 Mustang GT before (top) and after the installation of the Bilstein BTS Suspension Upgrade Kit. The kit lowers the car approximately 1" in the front and 1.5" in the rear, giving it a great new stance to go along with the significantly improved control and handling characteristics.

Bilstein BTS Kit Proves There’s always Room For Improvement

  • Designed for 2005-2011 S197 Mustang V6’s and GT’s
  • Coil springs are tuned to a specific spring rate
  • Front monotube gas pressure struts are designed and tuned for the Mustang
  • Ride height is decreased 1″ in the front and 1.5″ in the rear
  • Offers significant increase in damping with a low shaft speed to eliminate the “loose shake” feeling
  • Large 36mm struts do way with rod flex for increased lateral stability
  • Self-adjusting digressive pistons instantly react and adjust to the road surface
  • Inverted tube technology originally designed for racing applications

Bilstein’s BTS – or Bilstein Tuning System – kit is designed for the 2005-2011 model S197 Mustang V6 and GT, and is designed to offer a dramatic increase in performance handling characteristics and appearance.  The BTS kit includes the four coil springs that sport a specially tuned spring rate, along with Bilstein’s monotube gas pressure struts for the front corners of the car and shocks for the rear with sport level valving specifically tuned for the Mustang. The technology behind this kit, which we will hit on, not only provides a greater ride, but lowers your Mustang roughly a half-inch in the front and 1.5-inches in the rear, providing a lower stance for better handling and control.

According to Lou Laurenza, Tech Department Operations Supervisor at Bilstein, “The OEM suspensions found on the Mustang have their shortcomings, including geometry issues, and lack of dampening and rebound. The higher-end GT500 actually falls short on these attributes even moreso than the GT with which we are installing the kit.”

The Bilstein BTS suspension kit includes direct replacement shocks and springs for both the front and rear specifically designed for improved handling and a smoother ride on the Mustang GT. These are non-adjustable shocks and come tuned directly from Bilstein

The S197 platform Mustang has gone through two different iterations of suspension layout in terms of springs and bars, with the 2010 model year seeing a marked increase in spring rate. “For 2008 and older Mustangs, our BTS kit (Part # F4-SE5-F351-H0) offers a significant increase in damping – and in particular – low shaft speed to eliminate some the loose shake. There’s also a pitch-forward aft issue on the GT and GT500,” said Laurenza.

After pulling the carpet in the trunk aside, the bolt holding the rear shocks in place must be removed to make way for the removal of the factory rear shocks.

The BTS kit utilizes Bilstein’s inverted tube technology in the front struts that were originally designed for use in motorsports applications that’s been trickled down to your daily driver. The large 36mm struts eliminate rod flex for unmatched lateral stability, and feature self-adjusting digressive pistons that will instantly react and adjust to the road surface. And, with the piston installed at the base of the strut tube, it is then completely protected from the common contamination that eventually wears down a strut and hinders it’s capability to offer the ride and handling you expect.

“Primarily what we’re looking for is better control, we’re always looking for comfort, we want to address any shortcomings that a vehicle would have coming from the factory,” said Laurenza. “And the primary issue that we saw on the Mustang would be pitch balance from front to rear, lack of control in the rear, quite a bit of axle travel under braking and acceleration, lack of responsiveness, and low shaft speed. So there were several things that we were going after on the car.”

The factory rear shocks are mounted to brackets on the rear end housing on each side using a single standard nut and bolt. The Bilstein BTS shocks are a direct replacement and use the very same mounting location, making installation a breeze.

With the S197 chassis, in particular the 2005-2008 models, it was common to experience excessive brake dive, loss of traction mid-corner, and “skating” where the car would tend to oversteer due to a soft spring rate. With the release of the 2010 and subsequent 2011 Mustang that features some changes in the suspension as already mentioned, Ford has attempted to shore up some of these issues straight from the factory. However, the Bilstein BTS kit still offers superior performance to the OEM setup, as is usually the case with aftermarket components.

The BTS shock and strut units are fully adjustable, however in order to do so, they must be sent back to the technical department at Bilstein to accomplish this. But while the kit cannot be ordered turn-key through Bilstein with a specific customer-specified adjustment, distributors for Bilstein products who specialize in suspension tuning will commonly adjust the shocks for you per your requirements at the time of purchase. “The tuning that is supplied off the shelf should suffice for more on and offroad use, such as autocross,” mentioned Laurenza.  If you’re building a full-on race car, then we would adjust it accordingly.”

The Tear Down And The Buildup

The install of the Bilstein BTS suspension kit really is so easy, a caveman could do it. The shocks and struts are designed to OEM specs, meaning there is no cutting, welding, clearancing, or other headache-inducing work to perform to get them on the car. Bilstein has also adjusted the rear spring ride height to avoid the bottoming-out issues seen in other manufacturer’s Mustang kits, giving you one less aspect to worry about. “We don’t typically recommend lowering it too much though, because of the lateral axle shift of the panhard rod setup,” says Laurenza.

The McPherson-style factory front struts come loose with four bolts on the upper shock tower and two on the spindle below. Be sure to hang on to the stock upper strut mounts, as they will need to be reused with the aftermarket Bilstein kit.

To install the rear shocks, you’ll start by opening up the trunk and pulling the plastic side panels apart to gain access to the mounting bolts. These carpeted panels don’t use clips or anything and will come off rather easily just by bending them back. Once you’ve done that, you’ll find a single bolt holding the shock in place that will be removed, followed by a lower bolt found underneath the car holding it to the axle housing. The shock and spring are then easily removable from the car. Up front, there is the standard OEM MacPherson strut, which consists of two bolts to be removed on the bottom, followed by four bolts inside the engine compartment atop the shock tower. There are then two additional bolts that hold the strut to the spindle to be removed.

With the four upper bolts removed from the shock tower and two lower bolts on the spindle removed, the entire front strut and shock assembly comes loose from our 2010 Mustang GT.

The front sway bar, which connects to the body of the strut must then be disconnected, followed by the brake line which also attached to the strut body. Finally, you will need a basic spring compressor to compress the spring in order to remove the primary shock bolt and release the upper caps. Be sure to hang on to the stock caps, as they will need to be reused with the aftermarket Bilstein kit. Installation of the new kit is virtually a rewind of what we just went over in the removal of the stock equipment, starting with the front shock and going from there. If you’ve done everything correctly, it will bolt right back up just like clockwork.

The BTS components reinstall in the very same manner as the OEM components - one lower shock mount to the rear end bracket and one bolt in the trunk

Our Post-Upgrade Ride Impressions

Once we got the Bilstein kit all buttoned up and the wheels and tires bolted back up, we took our GT out for a little spin to get a good feel for the difference in handling and performance. And of course, such a test wouldn’t be sufficient if we did anything other than stand on it through a series of acceleration, braking, and cornering maneuvers. And just as advertised, we were impressed with the increased results over the stock equipment.

The Bilstein spring and shock package drastically reduced body roll in the corners, keeping the Mustang planted. Also brake dive was virtually eliminated, decreasing our stopping distance.

With the new setup, there is a definite increase in overall feel of the road while cruising, less body roll when cornering, and a much tighter grip to the road. In essence, it’s much more reactive. Under braking, the nose of the car stays nice and stiff with little to no dive in the nose of the car. Under acceleration, thanks to the shock technology and the lowered ride height, the car stays nice and smooth rather than squatting or dipping as it used to. We then took it through some high-speed corners, performed some quick u-turns and such and the car elicits a night and day difference in handling, with far less body roll. Overall, the car feels much tighter and more responsive to your guidance.

Conclusion

This upgrade kit from Bilstein provided exactly what we were looking for in a suspension upgrade to compliment the powerful engine modifications in our Mustang, with virtually everything one could crave in terms of added handling, control, and responsiveness. The lowered ride height serves to plant the horsepower to the ground much better than the stock suspension is capable of, and as an added bonus – and a very important to many, at that – your ride comes out of it with a killer new stance that is sure to turn some heads. We’re not saying there’s anything wrong with the Mustang from the showroom floor, but you can always improve upon it and that’s the beauty of it all.