Muscle Mustangs & Fast FordsHow To Chassis Suspension
Turn Baby, Turn
Boosting the handling prowess of a 2001 Mustang GT with an Eibach Pro-System-Plus performance suspension system.
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For years, the Mustang has had a reputation as being a potent straight-line performer from the factory, but somewhat lacking when it comes to taking turns. While we know this is far from true, especially when talking about the SN95-series cars, there is plenty of room for improvement.
Ford builds lots of compliance into its suspensions and with compliance comes compromise. The stock suspension system on the '99-present Mustang GT is quite competent in unmodified form, but when given the chance to be modified the end results are usually welcomed and much improved.
Crazy Horse Racing shop owner and New Jersey resident Chris Winter and his wife Christina own a 2001 GT and were looking into ways to increase the handling potential of their machine. Chris, being a serious road racer, knows what it takes to make a car go deftly around corners, and was leaning toward scrapping the stock springs, struts and shocks in favor of a new and improved street/open track setup, but he didn't want to destroy the beautiful ride of their practically new car. Their silver GT is mostly stock save for a few bolt-on engine items and has run in the 13.80s on the strip. The car was purchased by Christina for everyday use and has an automatic transmission. When we learned of the new Eibach Pro-System-Plus performance suspension system, which includes springs, shocks, struts, front sway bar bushings and front and rear sway bars, we knew we had the ideal candidate on which to install and evaluate it.
For before-test numbers, Chris took his wife's GT around the new 1.35-mile road course at Old Bridge Township Raceway Park in Englishtown, N.J., with editor Jim Campisano riding shotgun to record the lap times. With the stock suspension, the car was surprisingly fast around the track, especially considering the automatic transmission. But Chris immediately became keenly aware of the excessive body roll, understeer and brake dive Mustangs are famous for during these aggressive maneuvers. Enter the Eibach setup.
Better Hardware For Better Handling
The Pro-System-Plus kit consists of new struts, shocks for the rear, bigger and heavier sway bars and improved bushings throughout.
"Our kit is designed for the more hardcore street (or race) cars, but can be used on the highway for everyday driving with no surprises or harsh riding," explained Dave Royce, the Suspension Development Manager at Eibach. "It is designed for the hardcore street hobbyist as well as the weekend racer. Maintaining the superb comfort level of the Mustang's ride quality was our main focus with this kit and we feel that we have done just that."
The shocks and struts do not offer any adjustment--you simply install them and forget them. As for the springs, Eibach will only say they are of the progressive rate variety. The Eibach sway bar up front is 30mm, or 3mm fatter than the stock GT piece, while the rear measures 24mm, same as a stock GT.
"The Eibach struts and shocks have a much more aggressive dampening feature built into them," explained Royce. "We don't rate the kit with spring rates (our springs are progressive versions), but rather what the entire kit is capable of. Our kits are designed to be used as a whole and are most effective in this form; however, you can use the shocks and struts by themselves (without the springs), but the kit won't be as effective."
Chris performed the install himself at his shop and began by jacking up the car to access the components. He started off by removing the two front tires so he could remove the front sway bar and with the two links unbolted from the lower control arms the sway bar was loosened and lowered from the car. The next step was for Chris to support the lower control arms with a floor jack so that he could unbolt the struts, which are the only item stopping the control arms from dropping to the ground.
He removed the two struts and after lowering the jack, the two stock (and tall) springs were pried out from their positions. Most springs are fairly hard to get into position but the Eibach springs are slightly shorter, which allows them to be placed into position fairly easily due to the fact that they don't need to be compressed as much. After replacing the springs Chris jacked up the control arms and installed the new struts.
With both of the struts and springs in place, Chris used the new (supplied in the kit) sway bar bushings and installed the new sway bar in the same manner as the stock one. "Our front and rear sway bars are designed to balance the entire Pro-System-Plus package," said Royce. "You can use the kit without our bars but they really add to the feel of the car."
Now that the front half was completed, Chris moved to the rear and repeated the process once again. He removed the two stock shocks and unbolted the two quad shock brackets from the frame rails. This enabled the rear to hang free, which allowed for the two rear springs to be removed with less of a hassle. With the two new springs in position (again, they were a little shorter, which eased the process) the two new shocks were placed into position and tightened down as well. The next step was to replace the stock rear sway bar, which is also bigger than its stock counterpart and should reduce the sideward sway of the rear end when experiencing hard cornering. It connects to the lower control arms with four bolts and was replaced in a matter of minutes. With the rear tires reinstalled and the car back down on the ground it became obvious immediately that the car had a new stance and, hence, a new, meaner and more aggressive attitude. "We designed this kit to have a lower ride height than stock and this is one of the reasons why it works so well," said Royce. "When finished, the front should be 1-inch lower and the rear should be 11/2-inch lower than stock. This kit is designed around the new, lower ride height of the car. We didn't just simply cut the springs to the lower the vehicle." We took it out for a spin down the road and the improved feel was evident right away. The nose dive that was present under hard braking was eliminated and the overall feel of the road was significantly better. Equally important was the fact that the ride, while firmer, was not buckboard harsh, as can be the case with some aftermarket setups.
Then we were back in Englishtown to give the Eibach-suspended pony another workout. Previously, our best time was 1:30.28 and Winter's prowess behind the wheel was evident by his consistent lap times. Chris was generating some decent lap times with the stock suspension system, but was complaining about the excessive body roll and nose-diving in the corners. With the new Eibach Pro-System-Plus kit in place, the body roll was much less noticeable and, because of this, Chris was able to drive into the corners much harder and generate better lap times in the process. With the Pro-System-Plus kit the lap times dropped to an amazing 1:28.83.
As important as road course numbers are, the car's street manners are also incredible. The exit ramp grand prix is now Mrs. Winter's favorite sport. Eibach obviously worked extremely hard on the Pro-System-Plus suspension kit to maintain the street comfort level and ride feel. At under $1200 for the entire kit, we have to tip our helmet to them for providing such a quality package.