Muscle Mustangs & Fast FordsHow To Chassis Suspension
Simple Superhero Suspension
Drive fast and look good doing it with a few simple mods to improve handling.
Believe it or not, those Ford engineers knew what they were doing when they designed the SN-95s. The slight increase in wheelbase and multiple chassis improvements made these cars the best-handling Mustangs to date. When combined with a PI-headed '99-and-up 4.6-liter powerplant, the GT is a fun ride on an autocross or road course. However, Ford's desire to keep the GT economical and inoffensive to the masses leaves the car lacking in the grip department, and it could also benefit from reduced body roll.
The simplest way to increase grip in any car is to add a set of stickier and wider tires. The '99 GT in this equation was one of the unfortunate ones to receive the base 16x7-inch wheels and 225/55HR16 all-season tires. This does not provide a large contact patch, and greatly reduces the braking and cornering capabilities. To fix this problem, BFGoodrich supplied us with a set of 265/40ZR18s that were obviously a lot wider. In addition, the KD model provides a much more aggressive asymmetric tread pattern, an AA traction rating, and a 200 treadwear, so you can bet they're a lot stickier.
Of course, every great pair of shoes needs feet to put them on, and the stock 16s definitely weren't cutting it. A set of rims can make or break a car, and with stock 16s this GT was in sorry shape, easily mistaken for a V-6. But a healthy set of 18s can change all that. Meanwhile, the car's black paint presented the perfect opportunity for that "pimperish" monochromatic look. Privat Wheels (a subsidiary of Konig) came through with the perfect match, the 18x9.5-inch Profil. Its optional high-gloss black spokes, mirror machined lip, and chrome rivet retainers are as high class as it gets. It's like drinking Bud Light from a glass.
Speaking of high class, for the springs and shocks we turned to our good friends at Tokico, which kicked in a set of the brand-new D-Spec shocks and struts. These newly designed units have a much wider range of adjustment than previous models, better lending themselves to cars such as this GT that would be seeing time on the dragstrip as well as the road course and in autocross competition. Similarly, the springs would provide a substantially lower ride height and improve handling without significantly reducing ride quality.
Unfortunately, on the dragstrip we would have two strikes against us with this new combo. First, the desire for a thicker sidewall (for a softer ride) increased the overall diameter of the tire by about 1/2 inch, which would kill some of the stock 3.27 gear ratio. Secondly, no matter how light a top-quality company like Privat makes its wheels, they may still be heavier than the tiny stockers, thereby increasing unsprung weight and rotational mass. The increase in grip, how-ever, should easily offset these disadvan-tages. Even with the completely stock motor and exhaust, it didn't take much to break loose the narrow all-season tires, so it would definitely be an interesting experiment.
Having success with the install on our new Exedy clutch and MGW shifter, we decided to make a return trip to Valley Performance in Belleville, New Jersey. The install went smoothly, as there were no projectile springs, and the Tokicos went in without a fight. In fact, technician Robert James said it was one of the easiest sets of springs he ever installed. The wheels and tires were mounted at another local shop, which brings us to an important point. Do not overtighten your lug nuts. Eighty or 90 pounds per foot are about all you need, but some impact guns go well over a hundred.
Three new wheel studs and a front-end alignment later, it was time to hit the track. In a previous trip to the 1.3-mile MM&FF road course, the 3,400-pound GT posted a best 1:28.15-second lap time. With the new wheels, tires, springs, and shocks, lap times dropped to an unbelievable 1:25.31 with less than optimal conditions. While the initial tests were conducted in sunny, dry conditions, our final test was conducted a day or two after a rainstorm, which left considerable standing water on the track at critical points, inhibiting grip. There's no telling how much more time test driver/Tech Editor Evan Smith could have lopped off had he been able to brake later and push the car a bit more in the turns.
Consider this--these lap times were only a couple tenths of a second slower than the exotic $56,000 Saleen S281 Supercharged tested last month--a car that makes 140 more horsepower than our stocker. In other words, the parts we added worked wonders. Anytime you can pick up nearly three seconds a lap on a 1.3-mile road course, you are making tremendous strides.
In any event, we were quite happy, not only with the lap times, but also in the overall feel of the car. It had now gained a confidence-inspiring sense of balance and grip that could not be outdone. Both Smith and head honcho Jim Campisano could not believe the improvement, and I actually had to pry the steering wheel out of their hands to make a few hot laps myself. It was a whole lot more fun practicing drifting around turn two when I didn't feel the back end would come around without warning, as it did previously. The new combination proved predictable in turn entry and exit, as well as taking away most of the understeer. All this with virtually no deterioration in ride quality--this was a best-of-all-worlds result.
At the dragstrip, the results were displeasing to say the least, as testing was plagued by a failing clutch. Apparently, the prototype Exedy stock replacement clutch was never meant to launch at the edge of the rev limiter with a set of slicks--it made a smoky departure in the waterbox at E-town. However, we will soon be rectifying this situation with one of the company's Hyper series clutches. Then we can play with the multi-way adjustable Tokico struts.