Improve Ford Drag Racing Suspension - Gotta Get Hook

The single upper control was first thought to be a burden to drag racing due to the single link and the questionable mounting point. Over time that has been proven wrong, as the single-body mount on the unibody is fortified from the factory. BMR takes it one step further and offers a sturdier upper control arm mount with a lower mounting hole. The lower mounting hole provides a more aggressive instant center, and the car will hit the tire harder.

Unique to the S197 is a Panhard bar setup. It runs diagonally across the rearend housing to prevent the side-to-side movement due to the single upper control arm. An added benefit of the Panhard bar is that it can help tweak the placement of the rearend and set proper wheel placement on either side. The lower control arms act identical as the Fox-body chassis setup.

"We think we have the quickest stock suspension S197 car, and it has run 8.02 at 180 mph," Spiker says. The car he is referring to is the in-house BMR racer that runs a push-rod engine with a single turbocharger and rolls on a pair of drag radial tires. They have received a best 60-foot time of 1.31 from the 3,450-pound ride. Add that to the fact that there are Fox-body Mustangs dipping into the 7.40 range on stock suspension, and it is hard to argue that the factory-style suspension systems can be successful in severe drag-racing applications.

Shocks, Struts, and Springs
Shocks and struts are as important to drag-racing performance as anything else in the suspension system. The average street car will benefit from going to the regular drag struts that have been labeled 90/10 style struts and 50/50 rear shocks. What those numbers refer to are that the 90/10 strut is easier to extend than it is to compress. It goes back to the idea of weight transfer and getting the front end to rise quickly and plant the rear tires. That shock and strut combination has become the standard in our industry for street/strip cars for more than a decade, and it works.

As you can imagine, shock and strut technology has come a long way, and an adjustable set of dampers can be had for only a little more money. JC Cascio of Strange Engineering shared some great information on the advantages of running a set of its adjustable struts and shocks. "The single adjustable strut controls the extension (or rebound)," he says. "The struts control how quickly the front end goes up. When the strut is loose, the front end will come up harder for weight transfer. The tighter the setting, the less weight transfer, which is required in some cases."

When a Mustang leaves the starting line, the body wants to separate from the tire and plant the tire. The shock will help plant the tire harder when run loose, much like the front struts. A stiffer shock slows down the rate of compression, and in some cases that is needed-like when the track is stickier than normal or if the car hits the tires too hard, causing the tires to rebound and break loose. If the shocks are too loose, the rear tires will shake as they grab and spin, grab and spin. If they're too tight, the rear tires will simply spin due to no bite. The adjustable shock allows fine-tuning for that specific car.

"I usually suggest guys start with three clicks from full loose with their struts and move stiffer if needed," Cascio says. "On the back shocks, start at seven clicks from full loose and tighten as needed. The final settings all depend on a lot of factors, like chassis stiffness, tire age, track conditions, and so on. You want to run everything as stiff as possible without spinning the tires so you don't waste any energy. People want to set the car up real loose. You don't want dramatic wheelstands and excessive body movement backwards. Sometimes people need that, but you should try to avoid it. A great example is to look at a Pro Stock car and see how little the body moves. Just enough to keep the tire hooked."

Everyone has an opinion on springs. Some guys told us they are just there to hold the car up, while others had some more insight into how a drag-racing spec spring works. Moroso's Brett McLellan recommends the company's Trick Springs for Mustangs. They are available for the front and rear. "The Trick Springs have a lower spring rate and are a taller spring," he says. "When installed, they are compressed, and that stores more energy." That stored energy is released when the car lurches forward. The front end rises-much like the struts-and the spring helps fling the front end in the air. Springs are also used to vary ride height, and everyone agreed that while a lowered car looks great, in some cases it might hurt dragstrip performances. The idea is to transfer weight rearward, and a lower front end could hamper that chore if there is not enough tire or power to overcome the center of gravity.

Front-End Modifications
The front end needs little help in order for a Mustang to be a track performer. The struts and springs are easily swapped out, and the only other major modification that enthusiasts perform is adding a tubular K-member and tubular A-arms. Along with those mods are also a coilover set of struts and caster/camber plates.

"Get weight off the front end," says Dario Orlando, whose company, Steeda, makes many components to lighten up the front of Mustangs. The amount of weight saved from a tubular K-member and A-arm setup can be as much as 67 pounds, says Martorella. He also says that swapping the front end in a Mustang could be done in a driveway in as little as three hours. Some added components to the front-end kit are a bumpsteer kit (to keep front tires parallel) and caster/camber plates (alignment adjustment to help steer the car straight at high speeds).