Muscle Mustangs & Fast FordsHow To Chassis Suspension
Mustang Mach 1 Suspension Upgrade - Prepare To Be Handled
Project Shake 'N Bake Gets Ready To Hit The Track With New Suspension From Steeda.
When we started project Shake 'N Bake, we wanted to take a reasonably priced, used '03 Mach 1 and make it a great all-around performer-something that would serve as reliable daily transportation, perform well at the dragstrip, and hold its own at an autocross or open-track event. Now that Shake 'N Bake is consistently in the 12-second zone in the quarter-mile, and we can drive it to and from the track with no issues, its time to step up the handling.
There were a few aftermarket suspension mods already in place when we took delivery of our Mach. Lowering springs, caster/camber plates, and mismatched replacement shocks and struts raised our level of handling to slightly better than stock-but slightly better than stock is nowhere near good enough. To make a significant change in the handling and driving characteristics, we headed to Pompano Beach, Florida, where the crew at Steeda Autosports went to work adding the needed components to greatly improve our lap times as well as increase our consistency on track.
Our suspension upgrades are centered around Steeda's new lightweight K-member for the SN-95 (PN 555-5078). The K-member is designed to replace the stock unit while reusing the factory lower control arms. It can be used with traditional coil springs or with a coilover setup. A mix of chrome-moly and low alloy steels helps reduce nose weight, with a 16-pound reduction when using stock-type coil springs and a 19-pound reduction when coilovers are in place.
The K-member is designed so the control arms can be mounted in one of two positions to fine-tune roll center geometry. The lower position is for cars that are stock height to 1-inch lower than stock, and the upper position is for Mustangs lowered 1 1/2 inch or more.
"When lowering the front end, the inboard end of the control arm gets closer to the ground," explains Aric Pogel, engineer for Steeda Autosports. "This has an effect on the roll center height. If lowered excessively, the roll center can go below the ground. With our K-member and coilovers, the control arms can be mounted to the upper set of holes to restore proper front-view geometry."
The steering rack bolts into the stock location and has the added benefit of adjustments to change the Ackerman geometry. Ackerman geometry allows the inside wheel to turn to a greater angle than the outside wheel in a cornering situation. This permits the inside wheel to have a tighter radius than the outside wheel, and is also referred to as dynamic toe. Under cornering, the inside wheel will toe-out, allowing the car to rotate freely around a corner.
With Shake 'N Bake on the lift at Steeda, Steve Chichisola went to work on our front suspension. After our wheels, brakes, spindles, and control arms were removed, it was time for the stock K-member to come out. With the help of Matt Bouyea, the Four-Valve power plant was secured and the stock K-member was removed. This is also a great time to take advantage of the open space and inspect/replace motor mounts, or make any other needed repairs or desired mods in this hard-to-reach area.
After the new K-member was bolted into place, Chichisola reinstalled the front control arms and steering rack. Once the front struts were removed, the caster/camber plates were removed in favor of the Steeda billet four-bolt caster/camber plates. Steeda's caster/camber plates are designed to spread the load across the entire strut tower, and provide a wide range of adjustment for street and racing applications.
With the caster/camber plates loosely installed, Chichisola installed the new struts. Tokico Performance Products sent us a set of its D-Spec adjustable shocks and struts. The D-Specs offer a wide range of adjustability between the full soft and full firm settings. An adjustable slide valve controls a unique variable aperture bypass, which allows compression and rebound to be adjusted simultaneously. "Tokico shocks and struts are designed specifically for each vehicle," explains David Chow, sales manager for Tokico Performance Products. "The D-Specs are designed for domestic applications, offer infinite adjustability, and are engineered and tested for the highest level of performance in a heavier vehicle." Being designed for a combination of drag racing, autocross, road racing, and street use, the D-Specs are the perfect choice for project Shake 'N Bake.
Once the struts were in place, the next addition to our suspension was a new set of lowering springs. Steeda Sport Springs lower the ride height 1 to 1 1/4-inch less than stock. The front springs come with a spring rate of 650 lb/in while the progressive rear springs have a spring rate of 200/250 lb/in. The stock coils check in at 600 lb/in up front and 200 lb/in the rear. The added spring rate helps control body roll and keep the vehicle level through hard cornering.
As our front suspension started to take shape, Chichisola bolted in the new front sway bar. Steeda's tubular front sway bar (PN 555-1094) is a 1.375-inch-diameter bar designed to compliment the heavier front springs and reduce body roll on the track and street.
After buttoning up the front suspension, Chichisola shifted his attention to the rear of our Mach 1. The first pieces to go would be our stock control arms. With the upper control arms removed, Chichisola began installing the Steeda HD upper control arms. These are designed for lowered cars, Chichisola tells us. The mounting holes on the rearend side are moved a quarter-inch forward to improve pinion angle.
Next, the lower control arms and rear springs were removed, along with the stock rear sway bar. The new springs and Steeda aluminum lower control arms soon took up residence where the stock pieces once sat. The Steeda aluminum lower control arms are engineered to work well in many forms of motorsports. These were the perfect candidates for Shake 'N Bake, since it sees many different track environments and a lot of street time.
With the new control arms and springs in place, Chichisola bolted the stock rear sway bar back into place and began measuring for the Steeda adjustable rear sway bar. This supplemental sway bar comes with spring-loaded end links to fine-tune the rear suspension to keep the car balanced. The best part is if you change or add other suspension components, with just a few turns of a wrench, the rear suspension can be dialed in for your individual driving style.
Once all of our new suspension components were in place and the car was back on four wheels, it was time to take care of the alignment. Chichisola rolled Shake 'N Bake onto the Hunter DSP400 alignment rack to get wheels pointed in the right direction. Being that we plan on running some autocross events and open track days, the crew at Steeda set our alignment on the aggressive side for the street. Although this is going to cause slight premature tire wear, the alignment will definitely help in the handling department.
With our suspension installation finished, it was time see what our Mach's capabilities. In our last installment, we ran Shake 'N Bake on the skid pad and slalom at Gainesville Raceway for our Nitto tire test. With the new suspension ready to go, we bolted the NT01s back on and headed out to the skid pad.
After a few laps in each direction and a little bit of math, our new average for lateral g's is 1.08-a good improvement over our previous 1.03g. From there we let our Mach loose on the 420-foot slalom. With the numbers tallied, our average mph through the cones was 45.03. This is a strong improvement over the 44.28-mph average prior to our suspension upgrades.
When all was said and done, we drove away with an entirely new-feeling vehicle. The handling characteristics have changed for the better, and the car feels much more connected to the road. The car reacts well to all steering and throttle inputs and really leaves you with a strong feeling of confidence, and we couldn't be happier!