Cameron Benty
September 27, 2018

You’re traveling at great rates of speed, Things are humming a long great and then a dreaded hairpin corner comes into view. Do you panic? Nope. You just swing out slightly, double apex the corner with amazing smoothness and then get back hard on the throttle relegating the competition to a mere dot in the rear view mirror. The newest Mustangs are awesome in many ways, but there are a number of things you can do to make them handle even better, and best of all, you don’t have to give up ride comfort.

Getting big power to the ground regardless of the curviness of the road can be truly frustrating especially when drivetrain upgrades are added to the mix. For the purposes of this article, we will focus on the front suspension upgrades and follow up with a secondary article on the rear suspension in the very near future.

Steeda Suspension offers packages for the 2015-2019 Mustang GT and EcoBoost vehicles. These kits come in two flavors: one for those vehicles with the original OE Performance Pack option and for those without. Once installed, both Steeda equipped kits ultimately deliver a similar level of handling performance.

Our subject vehicle was this 2018 Mustang GT that was previous upgraded with a brand new Vortech supercharger system. With all that added power it was time to make sure the power reached the road in a way that was efficient yet comfortable for this daily driver.

It’s in the Spring!

Much of the improved handling centers around Steeda’s use of progressive rate springs. What that means is that for regular driving, the spring rate is fairly soft but when compressed through the application of increased cornering G’s, it engages the higher rate portions of the spring for increased “push back” to control roll and squat. That means that while you’ll have the potential for high rates of spring pressure when carving a high-speed corner, you won’t have to worry about the comfort of your passengers when taking long trips.

As our 2018 Mustang did not include the factory Power Pack option, we ordered up the appropriate Steeda S550 Mustang GT handling kit that included the front and rear progressive springs (the front springs range in rate from 220 lb/in but to 350 lb/in and the rears from 800 lb/in to 1,200 lb/in), non-adjustable front struts and rear shocks, adjustable rear toe links, front camber plates along with the front and rear sway bars.

For some Mustang owners, this level maybe more than enough to achieve a heightened performance suspension experience. For others, they will need a bit more. It should be noted that this kit lowers the front end 1.125-inches over stock height and 1-inch in the rear, to the benefit of front-end aerodynamics and lower roll center/center of gravity.

Because we were looking to do some serious autocross along with limited “big track” driving, we opted for the next steps in Steeda suspension upgrades, which meant the addition of the subframe alignment and support kit, the ultimate “stop the hop” kit, the strut tower brace, Ultralite 2-Point G-Trac brace and rear camber adjustment kit. Each of these parts worked in tandem to improve the handling and acceleration-from-stop performance. Again, for this article we are only dealing with the front suspension upgrades, but as you can see, there are some big plans for the rear as well.

Steeda offers a wide diversity of suspension components to achieve various levels of handling performance. For our front end upgrade just some of the Steeda exclusive parts we installed included (clockwise from top right): Gas-charged front struts, bump-steer kit, strut tower brace and progressive rate springs.

Alignment is key

To unleash the full potential these parts can deliver, a full alignment, both to the front and rear suspension is of critical importance once all of the parts are in place. In terms of alignment specs, Steeda recommends -1.2 degrees front suspension camber and – 1.5-degrees camber in the rear. Caster settings should be 7.21-degrees per side and overall toe in should be 0.20 degrees. For performance driving on race tracks, increasing the negative camber will help “stand the tire up” in hard cornering for better grip.

Bump Steer Basics

The concept, that for each action there is an equal and opposite reaction, is also true of suspension adjustments. When you lower vehicle, you change the angle of the tie rods. This become most clear when you encounter a dip in the road as the altered tie rod angle will cause the tires to toe in or toe out before returning to the original spec. Toe out settings will make the vehicle very hard to control, the tires heading off in basically two different directions rather than in tandem. With Toe in, the tires scrub off speed and waste time when driving around a course. For that reason, Steeda created their bump steer kit that allows you to adjust the tie rod by moving the tie rod end up or down accordingly. This simple correction makes a remarkable difference in vehicle Bump Steer issues.

As we mentioned earlier, we broke the story into two different sections; the front half and the rear half. Taking time to shoot photos of the installation and working on a lift for ease of install and reporting on each step required about four hours per vehicle “end.” We used an assortment of impact and electric drives along with hand tools including a recently calibrated torque wrench. It is easy to be overly zealous with power tools so make sure that you check the specs and follow the detailed instructions in the Steeda manual.

Our host for the day was Saul Gutierrez, owner of Gear Driven Automotive in Reseda, California. After laying out the large array of Steeda Parts designed to upgrade our 2018 Mustang GT, we set to work.
The anti-lock brake sensor fits into the back of the caliper and is held in place with one 10mm bolt. Remove the bolt and pull out the sensor. We put the bolt back in the original hole to avoid losing it. Don’t kink or pinch this ABS line!
Release the top link to the sway bar by unbolting the top stud in this link. The hole to the left of the link is the point where it originally attached to the strut housing.
Of key importance here is to note that the bolt is splined and will not turn. The Bolt needs to be tapped out from the nut side with a dead blow hammer; as the bolt is not threaded to the tip, this can be done without damaging the threads. Remove both bolts that hold the strut in place.
As opposed to the case with the previous strut bolt where you can’t hurt the threads, you can damage the threads on the tie rod end. After removing the nut from the top of the tie rod end, hitting the spindle eyelet at this point while pulling down on the tie rod should spring it free. Don’t be gentle, but don’t miss.
Remove the front underbody covering by removing the lower screws that hold it in place. Most of them are very obvious.
Under the heading, not so obvious, are the plastic pop rivets that are located inside the wheelwells. This tool, available at many auto parts stores, makes removing these kinds of fasteners easy and reduces the chance of damaging these plastic rivets.
The sway bar is held to the frame with a pair of straps that wrap around the bar. Remove the four bolts that hold the straps to the frame; there are two on each side. With the end link released and the hold down straps completely out of the vehicle, the front sway bar can be slid out of the suspension. Removal of the tires and brakes are helpful in provide clearance but even so, the bar takes some wrestling to feed it out of car.
The factory front sway bar measures a beefy 1.267-inches, that’s plenty big in terms of OE front sway bars.
The rear sway bar measures 1 3/8-inch and features an 0.250-inch thick wall for added resistance to bending.
Next, after opening the hood, remove the nuts that hold the strut at the top of the shock tower. Note that removing the last nut will release the entire strut system so be ready and have someone ready to lower it out.
There are a wide variety of spring compressors on the market and this is one of the more typical styles. Note that the compressor has to work around the strut’s larger base plate (the resting point for the spring). You can often rent spring compressors from the local auto parts store.
After compressing the spring fully, we removed the nut holding the top of the strut mount and then slowly released the spring compressors. This can be very dangerous so be careful and make sure that the compressors don’t slip off.
The difference in the stock spring (left) and the new Steeda spring are shocking. Note that the stock spring is more linear (same from top to bottom) and the Steeda spring is progressive with both tighter and wider spring coils. This is why they ride nice for cruising down the road and stiffen up when they experience hard cornering.
Due to the shorter spring height and reduced spring travel, the internal polyurethane bump stops must be cut down; we cut them as shown here.
The strut is assembled in this manner, including the supplied white washer, cut down bump stop cushion and factory dust cover.
With the spring under compression, the strut cushion and Steeda strut camber plate can be installed and the center nut tightened in place. Note that both top and bottom cushions notches built into them that denotes where the end of the spring’s coils should seat.
The slope of the coil spring windings caused the top cushion to not sit flat on the spring. With the factory spring this was not an issue since the OE spring was flat on top. With the new top Camber plate and cushion installed, there is a gap between the coil and the cushion. This is not an issue since they will flatten out once the weight of the car presses down on they spring and strut.
This is what the strut and spring assembly looks like once the spring compressors are fully removed. Torque the center nut to 59 ft-lb.
These spacers are used to support the Steeda Shock tower brace which will be installed at the same time we install the struts since some of the strut tower bolts share the same hold down nuts. In our case there were two spacers on the passenger side and six spacers on the driver’s side shock tower.
The spacers look like this when they are in place and tightened down. This is a key alignment point that will be adjusted during the alignment of the front end.
The Steeda Shock Tower Brace does a great job eliminating the movement of the shock towers. This is the proper positioning of the shock tower brace and you’ll notice that on the passenger side of the car that the brace slides under the wiring loom.
This shows the proper nut placement and tower brace location on the passenger side of the vehicle. Again, after the strut is in place the suspension must be aligned using a professional alignment rack.
Reinstall the bolts in the bottom of the new Steeda strut, reversing the operation completed to remove the factory strut. You will have to press up on the strut to compress the gas charge in the unit before sliding these bolts in place.
With all of the threads on the bolts and nuts started by hand, we ran each fastener down to a snug position with an impact gun and then hand torqued them to the correct specification.
This spacer plate fits into the ends of the Ultralite 2-point G-Trac brace to provide clearance for certain long tube headers. Like the shock tower brace, this underbody brace helps firm up the front end reducing flex and keeping the tires square with the ground.
Each end of the brace bolts into holes in the support braces that cross under the engine compartment. Steeda supplies new hardware for this component.
This image shows the full placement of the Steeda 2-Point G-Trac brace.
To counteract the changes to the suspension component angles due to lowering the Mustang, Steeda’s bumpsteer kit features these extenders, which allow you to change the angle of the tie rod.
These handy little devices from Steeda feature a series of washers, which you can place either above or below (or a combination of both) the tie rod swivel. This way you can move the tie rod to near level with the ground positioning and reduce bump steer that can cause an unpredictable steering reaction to less than smooth road surfaces.
Sway bars make a huge difference in overall suspension handling by reducing and controlling body lean. These polyurethane mounts are thoroughly covered inside with Steeda supplied lubricant to avoid noise and internal binding.
As was the case with the front suspension, the new, larger diameter bar is threaded through the body into the correct position in the chassis.
We wrapped the new polyurethane mounts around the bar and strapped them in place with these hold-downs.
The new Steeda front sway bar features four different leverage points, allowing for significant adjustment to alter the understeer/oversteer manners of the suspension. Steeda’s innovative billet sway bar ends (made from 1018 steel) provide durability and added leverage.

Steeda Part list*

• 555-8210 - 2015-2019 Steeda Mustang Front Sport Springs - Progressive
• 555-1015 - 2015-2019 Steeda Mustang Front Sway Bar
• 555-8139 - 2015-2019 Steeda S550 Mustang Camber Plates
• FR3Z-18124K - 2015-2019 Ford Performance Pack Front Struts
• 555-5533 – 2015-2019 Steeda Mustang Ultralight 2-Point G-Trac Brace
• 555-5731 – 2015-2019 Steeda Mustang Strut Tower Brace

(*Front suspension only)

Package benefits

• Improves vehicle handling
• On-car toe adjustability
• Improves suspension compliance
• Increases traction
• Aligns subframe to chassis
• Limits IRS sub frame movement
• Reduces wheel hop
• No added NVH