When we purchased this SN95 14 years ago, it sat nicely, riding on a set of BBK Gripp springs and Tokico blue shocks. Once we swapped the 9-inch rearend in it, the car sat much higher than before, almost higher than a stock SN95. Since the car always seemed to ride OK, we weren’t all that concerned with some wheelwell gap. However, as the car has aged, so has the suspension, and this spring, it became clear that we couldn’t put off dealing with it any longer. With the new TKX transmission in the car, we were once again able to actually flog the car, so the aged suspension’s shortcomings became very apparent. We saw QA1’s recent announcement for SN95 handling packages, and our curiosity was thoroughly piqued. After reading the different levels of kit offered, and a quick discussion with QA1’s Dave Cass, we decided on the QA1 Level 1 Handling Kit for our SN95 to restore (or improve) its handling while offering ride quality compliant enough for a daily driver.
What’s Included In The Handling Kit
Before we dive into the specifics of our kit, a quick overview of the different kits available will set the stage. QA1 offers two lines of kits: handling and drag. Within each of those lines are Level 1, 2, and 3 kit. Each level of the kit adds more suspension components in the box. The components are similar between the handling and drag kits, but are tailored to the requirements and nuances specific to each discipline. So, for our Level 1 Handling Kit (PN HK41-FMM4, $2,566.95), we received a box containing a pair of single-adjustable Proma Star front strut coilovers, a pair of single-adjustable Pro Coil rear coilovers, caster/camber plates, and a new upgraded front sway bar with new urethane bushings and end links.
In addition to the kit, we also opted for a pair of QA1’s boxed lower control arms (PN 5221, $367.95), which we’ll dive into the details of in a bit. The one-box solution… well one part-number, we should say, as the Level 1 Handling Kit arrives in multiple boxes, makes life easy. It eliminates any chance of incorrectly selecting the wrong parts and ensures that all of the parts work well with one another for your application. So let’s dive into each of the components individually.
Proma Star Front Strut Coilover Kit
The Proma Star Front Strut Coilover kit actually comprises three major components: The Proma Star Strut, the coil spring spec’d specifically for your vehicle and application, and then lightweight caster/camber plates. The Proma Star Struts are available in single- or double-adjustable variants, with the single-adjustables coming in the Level 1 Handling Kit.
The strut is built with a unique “inverted strut” cartridge design, allowing for a much larger-diameter shaft that better withstands side loads found in aggressive cornering and braking. The threaded body of the shock is made from aluminum to reduce overall unsprung weight which is always welcome in a performance application. Rebound valving adjustment comes via 18 positions adjustable via the convenient star knob on top of the strut. Getting your adjustment just right is easy, thanks to the positive “clicks” provided by the ball detent.
For the springs, QA1 has selected a firmer 200-pound-per-inch rate for the Level 1 Handling Kit than they provide on the Level 1 Drag kit. While the 200 lb/in springs are the same on the Level 1 and Level 2 handling kits, the Level 3 kit gets even firmer 300 lb/in coils. The spring length is designed to provide a stiff but compliant ride, and the threaded body allows for up to two inches of ride height adjustment.
Topping off the front kit are QA1’s Caster/Camber plates. Made from aluminum, they are both strong and lightweight. Besides allowing significant adjustment of both camber and caster (as the name suggests) they allow precise adjustments, thanks to their laser-etched adjustment markings.
Pro Coil Rear Shock Coilover Kit
The rear shock coilover kit included in QA1’s Level 1 Handling Kit is unique, in that it converts the rear suspension to an actual coilover setup. Often times seen in drag racing setups where there are no “stock suspension” rules, this configuration allows for better control of the vehicle’s movement as well as allows for convenient ride height adjustments.
[Ed note: coilovers change the ride height by moving the mounting point for the spring, which means the shock travel remains unchanged when static (unlike when the spring is mounted separately on the lower control arm). That’s why they can do a better job of controlling the vehicle’s movement and ride better for a variety of reasons we won’t go into here.]
Built around QA1’s proven Pro Coil threaded-body shocks, the rear coilover kit is an exceptionally thoroughly engineered kit that pays incredible attention to detail. The single-adjustable shocks included in the Level 1 Handling Kit adjust both rebound and compression simultaneously and, like the front struts, have 18 clearly (tactilely) defined adjustments from “soft” to “hard.” The spring length and threaded spring perch design allow for up to two inches of ride-height adjustment, matching the fronts.
The spring rates in the rear are unique. Firstly, you can’t make a direct comparison between the QA1 spring rates and typical SN95 rear spring rates, as the springs are in a different location. The 130 lb/in spring rate included in the Level 1 Handling Kit is the lowest spring rate offered in the “handling” line of kits, and is designed to provide a balance of improved handling and comfort on the street.
Since the traditional shock mount in an SN95 isn’t designed to carry the load of both the shock and spring, QA1 includes a beefed-up mount, often called a coilover mount. It is made from thick plate-steel and attaches to the rearend housing with heavy-duty Grade 10.9 bolts. Similarly, the upper shock mount adapter is made from plate steel, and fits through the mounting hole in the trunk of the car, adapting the Pro Coil shocks upper eyelet mount to that of an SN95.
1994-’04 Mustang Front Sway Bar
The final components in the QA1 Level 1 Handling Kit are a new front sway bar, urethane mounts, and endlinks. Designed to improve stiffness without adding weight, QA1’s engineers designed a 1.25-inch outer-diameter sway bar, but hollow. The 4130 chromoly steel tube has a 3/16-inch wall thickness that provides a solid balance between weight and performance. Included with the sway bar are a pair of replacement bushings made of polyurethane, to minimize deflection while allowing some compliance. Mounting the sway bar to the control arms is a set of all-new endlinks with the same polyurethane bushing material as the sway bar mounts.
QA1 Boxed Lower Control Arms
One of the things that this car has gone through is a multitude of different control arm setups, all looking for the right blend of performance and a smooth ride. In our previous quest to try and lower the car with its altered suspension geometry, we installed adjustable-perch control arms. Since the coilover kit relocated the spring, going back to a traditional straight control arm seemed like the appropriate choice.
QA1’s boxed trailing arms are much stiffer than the OEM stamped arms, but their box-tube design keeps the weight in check. The ends are fully sealed to keep debris out, and they are powdercoated for a long-lasting, durable finish. Additionally, they feature greasable polyurethane bushings. These will stiffen up the suspension, for a more precise, responsive feel, but aren’t so harsh as to knock loose any fillings or kidney stones.
Installation Of The Level 1 Handling Kit
With plenty of experience playing with Mustang suspension under our belt, the installation process of QA1’s Level 1 Handling Kit was incredibly straightforward. That said, even with minimal to no experience swapping suspension on your Mustang, this is still definitely a DIYable project. The most challenging part of the process is safely removing the stock springs, as the stored energy can be a challenge to safely dissipate.
The only step that isn’t present on any other spring and shock/strut swap, is that you need to drill a single hole in each of your shock towers for the installation of the caster/camber plates. Other than that, it’s all nuts and bolts, and completely typical of a suspension swap. While the QuickJack 5000TLX portable lift made life super easy, you can easily complete this project in your driveway, on jack stands, in a single afternoon.
Ride Quality And Our Final Thoughts
Since we completed this project in the middle of the Arizona summer, our friend Ed Zinke was kind enough to let us use his garage (and PortaCool) for the swap. Besides the helping hands, and climate control, swapping the suspension at Ed’s had another benefit; the short drive home includes two medium-speed roundabouts with smooth, almost racetrack-like curbing on the inside.
So even while trying to be responsible and obey all traffic laws, as well as taking it easy to listen for any strange noises after the installation, the difference was night and day. This Mustang has never, in the 14 years we’ve owned it, regardless of what suspension and rearend combination we’ve had in it, driven this nicely. We’ve often noted the incredible difference between our S550 and SN95 through the roundabouts around town, but that difference is gone. Actually, that’s not fair. If anything, the SN95 now has a slight edge on the S550, especially with the gearing of the TKX being just right to rip through the roundabouts — all within the speed limit, of course.
While the QA1 kit commands a healthy MSRP, it’s absolutely worth it in your author’s opinion. Had I known this was the transformation that was in store, I would have done this years sooner. And, on a completely subjective note, the car looks better than it ever has, finally getting most of its stance back to where it was before the rearend swap. As you see in the photos, it was exactly as it was installed. That is pre-tensioning the springs half-a-turn and locking them down. There is still plenty of adjustment to play with. I might fiddle with the height a little still, when it cools down (as I write this, it’s still in the mid-90s outside). But, as it sits, it performs perfectly, and the car drives better than it ever has before.