Tech: Shelby GT350 Suspension Upgrades

0 2016 Shelby GT350 Suspension Upgrades Featured

Hummingbird Hook

Evolution Performance preps its Shelby GT350 for the strip with BMR

By Steve Turner
Photos courtesy of Evolution Performance

There is no doubt that the new Shelby GT350 is the best handling Mustang produced thus far. Ford Performance engineers took the S550 platform to new heights with a wider stance, improved aerodynamics, Magneride dampers and more. However, it also features a full suite of driving modes, and one of those modes is Drag Mode.

Evolution Performance wasted no time getting its new Shelby GT350 project to the drag strip, but first the company decided to install some sticky Mickeys and bolster the suspension with a full complement of upgrades from BMR Suspension.
Evolution Performance wasted no time getting its new Shelby GT350 project to the drag strip, but first the company decided to install some sticky Mickeys and bolster the suspension with a full complement of upgrades from BMR Suspension.

Yes, Ford Performance knows its customers. While most GT350s will spend time on the street and road course, some will head for the drag strip. While the gearing of this car’s transmission and rear axle aren’t ideal for the 1,320, the allure of seeing how quickly the high-winding Voodoo 5.2 can cover the quarter mile is undeniable.

One of the first of these cars to hit the strip is owned by Evolution Performance. As regular readers know, this car became the first GT350 to run in the 11-second zone with an 11.96 at 116 mph at Cecil County Raceway.

You can watch that run here…

Before heading out to the racetrack, however, the Evolution team decided that some sticky tires and suspension upgrades were in order.

Rather than all-out slicks, Evolution chose fully streetable Mickey Thompson 325/30-19 ET Street SS tires to follow the street/strip theme of this project. “The reason we ran that size is it’s a little shorter than factory, so it puts a little more gear in the car, because there are no aftermarket gears to put in there right now,” Evolution Performance’s Fred Cook said. “If there were gears available, I would put a 4.30 in it right now.”
Rather than all-out slicks, Evolution chose fully streetable Mickey Thompson 325/30-19 ET Street SS tires to follow the street/strip theme of this project. “The reason we ran that size is it’s a little shorter than factory, so it puts a little more gear in the car, because there are no aftermarket gears to put in there right now,” Evolution Performance’s Fred Cook said. “If there were gears available, I would put a 4.30 in it right now.”

“Just like all the previous ones, the car suffers from severe wheel hop. Wheel hop just makes you break stuff a lot quicker,” Evolution Performance’s Fred Cook explained. “Instead of breaking parts on a car that are probably impossible to get right now, we figured that it was cheap insurance. Plus, it is imperative because trying to do a burnout in a car with wheel hop is a waste.”

To ensure they had traction and didn’t break any parts, the first step was to install a pair of Mickey Thompson’s street-legal ET Street SS tires that are a bit shorter than the stock tires, to add some gear ratio since there are no numerically higher ratios available for the Super 8.8 yet.

Since the GT350 features numerous suspension tweaks when compared with its mortal S550 cousins, the Evolution crew disassembled the car to see what would work and what wouldn’t. If you been closely following information of this car features counter-spun springs, which required a new lower control arm design. That means you can’t run springs designed for EcoBoost, GT or V-6 Mustangs on this car.
Since the GT350 features numerous suspension tweaks when compared with its mortal S550 cousins, the Evolution crew disassembled the car to see what would work and what wouldn’t. If you been closely following information of this car features counter-spun springs, which required a new lower control arm design. That means you can’t run springs designed for EcoBoost, GT or V-6 Mustangs on this car.

Then there was the matter of selecting the right suspension mods to put down the power at the track without making the car unlivable on the street. Ultimately they chose to install a host of gear—including Adjustable Toe Rods (PN TR005; $209.95), Billet Vertical Links (PN TCA045; $189.95), Cradle Bushing Lockout Kit (PN CB005; $159.95), Differential Bushing Lockout (PN BK054; $49.95), and Lower Control Arm Bushings (PN BK055; $169.95)—from BMR Suspension.

“From the perspective of covering every base on the vehicle for what we are trying to do, I felt like BMR had the best full package, front to back; Especially their lower control arms bushings, which we pressed in,” he said. “They are probably one of the most important parts to change out, and a lot of people don’t realize that.”

Some of the factory rear bushings are spherical, but some sacrifices to the NVH gods are the rubber rear control arm bushings. Apparently they allow a lot of fore and aft movement of the rear tires.
Some of the factory rear bushings are spherical, but some sacrifices to the NVH gods are the rubber rear control arm bushings. Apparently they allow a lot of fore and aft movement of the rear tires.

Uncertain that the bushings would fit the new GT350 lower control arms, the Evolution crew resisted installing these bushings. In fact, on that first 11-second pass, the stock bushings were in place. Those passes illustrated the need for the more precise spherical bushings.

“Initially we didn’t install them. The first time we went to the track we had everything installed but those and we still had about 40-percent wheel hop. I wouldn’t necessarily say it was up and down, but front to back,” Fred said. “Once we switched them out, it is definitely a little stiffer back there, but is it creaky? Is it noisy? No. And they definitely made a hell of a difference.”

On its first trip to the drag strip, the Evolution GT350 still wore the factory lower control arm bushings, but before the car’s second drag strip trip the Evo crew removed the factory bushings and pressed in these spherical bushings from BMR, which they report made a significant reduction in wheel hop.
On its first trip to the drag strip, the Evolution GT350 still wore the factory lower control arm bushings, but before the car’s second drag strip trip the Evo crew removed the factory bushings and pressed in these spherical bushings from BMR, which they report made a significant reduction in wheel hop.

With the new bushings installed and a hotter tune from Lund Racing uploaded to the PCM (more on that in a future story), the team headed to Maryland International Raceway for some more hits. There Evolution’s Nelson Whitlock was able to click off an 11.76 at 118.83 mph with only a tires, tune and suspension. And, this car is no lightweight.

“The weight of the vehicle with Nelson in it was 4,020. Our car has the Tech package in it, so the leather seats, back seat, nav, all that stuff is in there,” he said. “There was zero weight reduction. The only thing that was changed, besides the suspension pieces were the rear tires.”

Once you start modifying the suspension of any S550, especially by adding lowering springs, the limited adjustability of the factory toe rods will become a limitation. The factory arms are stamped steel and can deflect under load. While the Evolution GT350 doesn’t wear aftermarket springs yet, they added BMR’s adjustable toe rods to rein in any unnecessary suspension movement.
Once you start modifying the suspension of any S550, especially by adding lowering springs, the limited adjustability of the factory toe rods will become a limitation. The factory arms are stamped steel and can deflect under load. While the Evolution GT350 doesn’t wear aftermarket springs yet, they added BMR’s adjustable toe rods to rein in any unnecessary suspension movement.

While this is just the beginning for this project, don’t look for this GT350 to become an all-out race car like some of Evolution’s previous Mustangs. This time they plan to mod this one into a potent street/strip machine. That doesn’t mean we won’t see some more aggressive mods, including a power adder, in the future.

“We have kicked around a lot of things, but we just haven’t settled on it yet. More than likely it will be a single turbo with an air-to-air intercooler,” he added. “…It’s never going to be a gutted race car, ever. Those brakes aren’t coming off. It will be one of those cars that you can drive to the track, race and drive home.”

Sounds like fun to us!

Likewise the factory stamped-steel vertical links leave a bit of strength to be desire. They aren’t that robust and they are fitted with rubber bushings, which adds up to a lot of unwanted suspension movement when you dump the clutch at the drag strip.
Likewise the factory stamped-steel vertical links leave a bit of strength to be desire. They aren’t that robust and they are fitted with rubber bushings, which adds up to a lot of unwanted suspension movement when you dump the clutch at the drag strip.
The BMR billet vertical is definitely a lot beefier in the stock unit and it is available with Delrin or spherical bushings, depending how much you want to sharpen the suspension.
The BMR billet vertical is definitely a lot beefier in the stock unit and it is available with Delrin or spherical bushings, depending how much you want to sharpen the suspension.
Like many of the other suspension bushings, the Super 8.8 rides in the cradle on rubber bushings, and the BMR diff bushing lockouts reign in most of that movement without removing the stock bushings.
Like many of the other suspension bushings, the Super 8.8 rides in the cradle on rubber bushings, and the BMR diff bushing lockouts reign in most of that movement without removing the stock bushings.
Like the suspension pieces, the IRS cradle is mated to the chassis via rubber bushings, which allow quite a bit of movement. As result, BMR crafted a clever solution—its Cradle Bushing Lockout system—which allows you to support the cradle solidly without removing the factory bushings. In front you loosen the cradle bolts one at a time and install the upper and lower lockouts.
Like the suspension pieces, the IRS cradle is mated to the chassis via rubber bushings, which allow quite a bit of movement. As result, BMR crafted a clever solution—its Cradle Bushing Lockout system—which allows you to support the cradle solidly without removing the factory bushings. In front you loosen the cradle bolts one at a time and install the upper and lower lockouts.
In back remove the cradle bolts one at a time and install the upper lockout with this robust lower brace, which uses the factory sheer plate mounting holes. This brace not only solidifies the cradle, but it actually centers the cradle as well thanks to its mounting lug.
In back remove the cradle bolts one at a time and install the upper lockout with this robust lower brace, which uses the factory sheer plate mounting holes. This brace not only solidifies the cradle, but it actually centers the cradle as well thanks to its mounting lug.

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