Bolting big power onto a Coyote Mustang is a relatively easy process in the modern era. That is especially true for the potent Gen 3 5.0-liter under the hood of the 2018+ Mustang. It is definitely the case with Evolution Performance’s Fred Cook and his silver S550, which we watched go from 500 rear-wheel horsepower with naturally aspirated mods and over 770 with a ProCharger. That power is great, but the next part of the equation is putting it to the pavement.
Just like the 2015-2017 Mustangs, the 2018s suffer from excessive deflection within the rear IRS system. — Kelly Aiken, BMR Suspension
“When you’re putting down almost 800 horsepower to the wheels, you need to be able to put the power to ground and have the necessary upgrades, so you don’t break anything,” Fred explained.
Evolution Performance technician Steven Schechterly laid out all the new gear (check out the sidebar for the full list) on a table before diving into the installation process. (Photo Credit: Jason Reiss)
Fred had already lowered his ride with Eibach performance springs and, after these updates, he added performance with a set of 20-inch HRE FlowForm FF04 wheels wrapped in Nitto NT555 G2 tires. However, in order to get the power planted it was time to address the pliable factory Independent Rear Suspension. To do so, he turned to a company that addressed those IRS shortcomings from the jump.
“BMR Suspension has been at the forefront with S550 suspension and chassis parts since day one,” Fred said. “The company’s extensive, real-world R&D combined with Kelly Aiken’s knowledge and support was a major part of my choice.”
Steven gets down to business by dropping the cat-back exhaust, driveshaft, and rear suspension. You could install the BMR bits with the IRS in the car, but dropping it down isn’t that tough and it makes it far more convenient to access all the necessary fasteners to get the job done quickly and efficiently. It helps that Evolution Performance has a custom-made jig to make the rear cradle removal process that much simpler.
As BMR’s Ford specialist, Kelly puts all his energy into helping develop and guide the company’s Blue Oval product line. Through that effort he has gained knowledge and experience that is passed on through to the hardware and the customers that use these parts.
“Two primary reasons we suggest performing an upgrade like this, especially on a supercharged S550 Mustang, are improved traction for better performance, handling, and driver confidence, plus less deflection of parts leads to less breaking of products, and better control of vehicle,” Kelly said.
Likewise, you might be able to install the BMR lower control arm bearing kit, but it is a heck of a lot easier to remove the arm.
To gain that durability and control, he suggests bolstering the IRS in specific areas to reduce movement and improve control.
“Just like the 2015-2017 Mustangs, the 2018s suffer from excessive deflection within the rear IRS system,” Kelly added. “The primary areas that deflect when loaded, in an amount that is not conducive to performance, would be the differential bushings, rear lower control arm bearings, subframe bushings, and vertical links.”
There is a method to these machinations, as Kelly suggests attacking the weaknesses in the following order, beginning by locking the subframe into place.
With the arms out, simply press out the factory bushing, and press in the BMR unit. These bearings are said to offer far more precision and control than the soft rubber factory units without adding in much noise, vibration, and harshness.
“We address this vertical, lateral, fore, and aft deflection of the IRS subframe with our most popular S550 IRS mod, CB005, which reinforces and firms up the IRS subframe mounting to the chassis,” Kelly explained. “This kit also positively locates the subframe as the stock IRS assembly can be put into different positions on the front mounts causing misalignment issues. Ours does not allow this. Also it is worth noting that our CB005 adds a convenient jacking point.”
Evo 2018 Mustang Upgrades
• BMR Suspension Billet Aluminum Camber Link with Delrin/Spherical Bearing (PN UTCA064)
Then Kelly likes to remove the compliance from the factory lower arms by swapping out the stock bushings in favor of BMR’s more precise option.
“The two front mounting/pivot points on the rear lower control arms are massive rubber bushings,” Kelly said. “The rears are a bearing-style bushing already, so we use the BK055 to completely eliminate the deflection of the front bushings of these arms under load.”
Mitigating the movement in vertical plane is also important as well. For a high-powered car, like Fred’s, he suggests the most precise option here as well.
“The factory vertical links feature rubber bushings. Not only are these bushings rubber, but the body of the links can also deflect and bend when heavy loads are applied,” Kelly explained. “For this we address that potential deflection with our TCA045 vertical links, which are billet aluminum and feature high-quality, US-made FK spherical bearings. Many times the consumer thinks that spherical bearings lead to big increases in NVH, but we actually have many people swap to BMR specifically for these TCA045 vertical links due to them being well-known to be the best performing and quietest-operating links on the market.”
With the IRS cradle out and on the stand, it was easy for Steven to install BMR’s differential bushing lockout kit and companion hardware upgrade kit that supplement the factory rubber bushings to more positively locate the Super 8.8 without transferring resonance to the chassis as solid bushings would.
With the IRS cradle held firm and more control at the end of the axles, keeping the factory Super 8.8 from bouncing around like a basketball is crucial to ensuring drivetrain durability.
“The factory S550 differential moves a lot in stock form, especially when racing the car. Knowing that Fred is making big horsepower, we wanted to remove the chances of him having driveline bind, vibration, and breaking issues by installing our simply solution to more positively locate the diff and keep it from rising excessively under power,” Kelly said. “I would like to add, we recommend these BK051 poly lockouts often to most all enthusiasts, as they help prevent the super-common issue of the rear passenger-side diff bushing cracking and splitting.
With the cradle bits installed, Steven raised the assembly back in place and bolted it up while incorporating BMR’s vaunted cradle lockout system. These braces and brackets keep the cradle from undulating on its rubber mounts. Like all the other parts of the IRS, keeping the cradle in place ensures that the geometry stays where it is meant to operate and provide a solid foundation for the suspension to work from.
With the differential locked in placed, Kelly suggested adding more control to the IRS itself, which also means reducing some of the give present in the factory system.
The car feels absolutely amazing. — Fred Cook, Evolution Performance
“Our UTCA064 camber links are designed for performance applications with big power increases. These specific pieces eliminate the factory rubber in favor of a bearing on the wheel side, and a custom Delrin bushing on the chassis side. The most notable feature of these is the fact they are longer than the factory camber links, which provides the user with the ability to get the rear camber close to 0.00 for street and strip applications,” Kelly explained. “One of the biggest downfalls with the S550 in terms of traction is the rear negative camber out back causing poor tire contact patch surface area, but what the UTCA064 also improves upon is camber gain — it does not gain as much camber during static-to-suspension compression movement as the stock-length camber arms do.”
Breaking a halfshaft won’t be an issue for Fred as these new Ford Performance Parts/GForce units are rated for up to 1,500 horsepower. They are a direct replacement for the stock shafts.
When lowering the car and making changes in the geometry, it is often necessary to add some adjustment into the system along with that extra control.
While the BMR Suspension upgrades will help plant this 2018 Mustang’s ProCharged power, you don’t want to just bolt on some sticky tires and let it rip with a stock driveshaft and halfshafts. To remedy those potential breakpoints, Fred Cook turned to GForce Performance Engineering for more durable gear.
“The upgraded halfshafts and driveshaft are a necessity at this power level, especially if you’re running drag radials or slicks and plan on taking the car to the track,” Fred said. “If these parts aren’t upgraded, you can most definitely count on breaking them at the track.”
GForce builds the stronger halfshafts for Ford Performance Parts as well as offering its own versions in two strength levels. The company also offers its own driveshafts, so they are one-stop shopping for fortifying your S550 drivetrain.
“I have been successfully using GForce Performance Engineering parts over the past couple of years,” Fred added. “Jesse Powell and his staff make extremely high-quality parts and that is all we use on our builds.”
Not only is the GForce driveshaft more durable than the factory piece, it is also 14 pounds lighter, which helps more power transfer to the rear wheels. The GForce unit is a direct bolt-on replacement.
Reeling in the vertical movement is also key to getting the rear suspension under control, but not for the reason you might assume.
“These provide a few benefits, but let me state this first — many companies promote these pieces for the wrong reasons. These do not help with wheel-hop reduction, and they actually offer little to no performance increase on 90 percent of the S550 Mustangs on the road. What the BMR units specifically are good for is preventing boosted S550 cars and race cars from seeing toe alignment slippage and change,” Kelly said. “These are also often needed when you go to the UTCA064 above, and perform a BMR-specific performance alignment. Since the toe and camber are related, when you set the camber out to zero or close, sometimes the stock toe-links do not offer enough length adjustment to extend them enough to put the toe within spec. In other words, our UTCA064 and zero camber out back leads to excessive toe-in. These links address that. Also, if you perform your own alignments, you will think these pieces are worth their weight in gold. The stock links are horrid in terms of fine-tuning adjustments.”
Ready For More
While Fred and the Evo crew definitely gave his car a performance alignment using that adjustability, he hasn’t hit the drag strip in the car just yet. He does say it delivers a far more confident driving experience on the street and in the corners. When he does hit the strip, he is expecting big things.
Finally, Steven bolted on the last batch of BMR upgrades, including its billet vertical links, billet camber link with spherical bushings, and adjustable toe rods.
“The car feels absolutely amazing. Not only did the car hook on the factory Performance Pack Michelin Pilot Sport 4S tires, but the car also handles great in the turns. The car also revs a lot quicker with the lighter aluminum driveshaft,” Fred added. “The car should run a high-9-second pass at the current boost level and factory weight. Next, I will be installing a new Corsa Performance 3-inch cat-back exhaust with active valves for the 2018 Mustang and upgrading the front and rear brakes.”
So, as with most Mustang enthusiasts, Fred isn’t quite done modding his powerful S550, but having a solid suspension foundation will ensure that his car is ready to take that next step with confidence.