When we tore out our '96 Mustang's original suspension three years ago, the fresh implants included Koni "D" Sport struts (PN 8741 1300) and shocks (PN 8041 1186), HP Motorsport caster/camber plates, and 1.5-inch lowering springs (450/570 lb-in front; 200/250 lb-in rear). A sharp wheel alignment (-1 degree camber, 5 degrees caster, 1/16-inch toe-in) brought everything into the proper perspective, and we completed the transformation with an Eibach pinion snubber that was 2 inches shorter than the original. We left the standard antisway bars, bushing material, and the upper and lower rear control arms intact. While all these products represent excellent performance in their own right, they were not designed to work with one another, nor did they account for the specific application.
In the months that followed, we never lost the appreciation for the dog's slinky, low-down stance, nor did we the acuity of purpose. We did, however, take issue with the way it bopped on down the road. The thing with lowering is that it robs wheel travel and turns the stock ride into rocks that bounce. Oh it looks cool, though, huh? You have to be a nutball to dig something as harsh as that. Looks cool, or gee, I really need the CG to be lower than it has a right to be because of that gymkhana I'll be doing this weekend? Right. But since our silly little fetishes are part of coping day to day, we must also seek the most comfortable ways to enjoy them.
Much in the same way the components for a successful engine combination are used because of their affinity for one another, so are the components in the Hotchkis Total Vehicle System (TVS). All this stuff has been designed and tested to work together to afford the best possible improvement but without the negatives of mixing the products from the Pool of the Great Unmatched. In the end, the Mustang was harsh and choppy and things were beginning to rattle and shake somewhere out of sight. We went to John Hotchkis on bended knee and with a plea: Make it ride nice, too. The gears inside his brain sped up for an instant and then ran normally again. He knew he could satisfy both qualities equally well.
Antisway Bars
Whenever possible, Hotchkis likes to remove mass without compromising integrity, so his hollow antisway bars are designed to produce the same torsional resistance as a solid bar yet weigh approximately 50 percent less, saving about 10 pounds of sprung weight (front) on a typical musclecar application. Hotchkis tests the bars for proper stiffness and chassis balance to ascertain the dynamic balance between oversteer and understeer, which is vital when negotiating fast corners. Hotchkis developed this system using a 600-foot slalom, a 200-foot skidpad, 60-0 braking tests, quarter-mile acceleration, and autocross testing, plus extensive street driving. In most instances, three rear and two front sway bar variations of rate and stiffness were tested to determine the best combination for handling and ride comfort for our Mustang.
Hotchkis used a 1-3/8-inch-od hollow bar and included polyurethane bushings (with grease fittings), heavy-duty brackets, fabricated end links, and all the necessary mounting hardware, as well as the stock mounting points. In the back half of the car, however, Hotchkis re-engineered the bar and its pickup points. The 1.0-inch hollow bar attaches to the axle and to the unibody rather than the OE location on the lower trailing arms. This design and the way it is mounted makes it a lot more efficient at controlling body roll because it doesn't have to bend and flex to follow the arc of the lower trailing arms. Hotchkis end links attach to the chassis using the OE quad shock mounts; that's OK because Hotchkis' fabricated lower control arms render those band-aids useless.
Coil Springs
To ride the critical line between comfort and sport, you need the flexibility of progressive-rate coil springs. Springs are new to the Hotchkis Mustang corral, so John & Company tested many different ride-height and rate combinations. The goal was to have the car as low as possible for ultimate handling and looks, but also to keep ride quality intact. Same old problem: Lowering reduces suspension travel, so the remaining travel must be managed well to avoid bottoming out. Bottoming out the suspension means no more travel or unlimited spring rate. The car will slide during cornering and bounce off bumpstops creating a maddeningly uncomfortable (and perhaps dangerous) ride. Though the prototype springs lowered our car 1.5 inches, the production versions will drop it an even 2 inches front and rear. The front springs, which support the car independently of the struts, are rated at 540 to 630 lb-in while the rear coils provide 250 to 360 lb-in. Since these rates begin where the rates for our old springs left off, we wondered whether the suspension would feel as tense as before.
Camber/Caster Plates
The biggest reason a lowered car doesn't ride as well as one at stock height is that the shock absorber has less room to travel. One of the benefits of the camber/caster plate is that it increases the travel of the strut by raising it in the car. The camber plates allow a much broader range of adjustment than the stock setup. The beefy Hotchkis plate features a thick aluminum base, bigger hardware, and another industry first: a micro cellular bumpstop, special shock boot, and spacers to vary the height of the strut. Techie Drew Oliver fed the following into the wheel alignment computer: -0.5 degree camber, +3.8 degree caster, 1/16 inch toe-in.
Rear Suspension
The Mustang comes with stamped-steel upper and lower control arms fitted with squishy rubber bushings. Since these arms positively locate and control the rear axle, they need to be as rigid as possible to null torsional changes and eliminate deflection and wheelhop. Similarly, cornering power is improved through increased roll stiffness and sway bar effectiveness. Our Mustang now has 100 percent TIG-welded arms fitted with polyurethane bushings of different durometer readings that allow the suspension to move through its travel more easily. The upper arms are adjustable for varied applications and reduction of vibration.
Proper pinion angle is important and for the most part overlooked when it comes to a performance-oriented street suspension. The Mustang exhibited some launch shudder and high-speed vibration, so Hotchkis shimmed up the transmission with two 1/4-inch spacers alongside one another. Accordingly, the yoke was tipped up to obtain the correct pinion angle.
Struts and Shocks
We've been using Tokico adjustable struts and (non-adjustable) shocks for nearly 20 years, and we've yet to dislike any one of them. We've never seen one fail, and we are enamored with their ease of maintenance. You can switch 'em (settings 1-6) from full soft to rip-the-mounts-out savage virtually in a second with a pocket screwdriver. They never have an artificial feel to them, and they were designed with the Hotchkis plan in mind. The ones in our car are set at 2 in the front and 1 in the rear. We wouldn't want any more than that, even for the freeways we must drive.
Tires and Wheels
Chosen for their no-nonsense simplicity and easy-to-clean faces, the Konig Villain one-piece rims are 17x9 all around. Like most wider-than-stock rims with a lot of negative offset, they cause the tires to rub the inner fenders when the steering approaches full lock. It's a nuisance, and there's that nasty scraping sound to mess with your cochlea, but there's no harm done. The Mustang GT wheel/tire upgrade includes 245/45ZR17 rubber. Just to be surly, we put BFG g-Force T/Akd tires (245/45 and 275/40) on the Mustang. After 10,000 miles, they ride quiet, bite down hard, and are favorable in the wet. Hard to beat 'em. Inflation is 32 psi.
What It Is
The difference was obvious right away. We hadn't been in the car in weeks, so the stuff that used to bug us was washed away by a completely new feel. The Mustang rides a little softer, and it's more fluid in the way it attacks berms and humps that tend to toss a car at freeway speed and put your head through the roof like the original Z51 Corvette. Thanks to the spacers, the vibration coming back through the transmission has been halved, but we believe the tranny might be shuckin' on its own. The freeway factor is less of one now, as the suspension soaks up irregularities with humor rather than guilt. Despite their higher rates, the springs feel no less accommodating than the softer-rate Eibachs.
Certainly, the Mustang has gained more than a little firmness in the bushing department. All of them are polyurethane now and peppered with zerk fittings, so what about squeaks? Drew told us to lube them every time we changed the oil. In all, a grand feat. On the handling side of the equation, the firmer bushings, relocated bars and links, and corrected pinion angle make the car feel of a piece. Steering turn-in is very sharp now, and the tail end hints at the outside when you exit a fast turn, the BFGs churning just enough to liven up the joint, all very smooth, controllable, and inviting. On the highway it feels like a job on rails.
Next
Right now, the red dog is having its cylinder heads replaced to fix monstrous oil consumption. Then back to Steve Cole's Turbo Shop for the electro-shock treatment that'll revive that 314 rear-wheel power figure we saw what seems like decades ago, hopefully more with the recent fuelie upgrades (see the Feb. '02 issue). If not, then maybe The Can, label and all.
