1997 Ford Mustang GT Suspension - Beginner's Luck

When I wasn't looking, the guys started in on the rearend, removing the differential cover and the lower control arms.

To stiffen up the chassis, Greg welded in a pair of subframe connectors. This alone will have a profound effect on how the car reacts, but we're not done there. A couple things to note when welding the subframes in place is to use a drive-up style lift to allow the suspension to be fully loaded, and also paint the solid steel bars with a rust-preventive paint once finished.

Griggs provides this differential cover, which includes a bracket that acts as the central control point for the Watts link setup. Also attached is a beefy torque arm that extends from this cover all the way to a supplied crossmember that mounts to the subframe connectors, just behind the transmission.

Probably the most difficult part of the installation was getting the right fitment for the main Watts link brace. Griggs recommends cutting into the spare tire housing, even providing an aluminum cutout to be riveted in place to allow room for the brace. I didn't want a riveted piece of aluminum on the bottom of my car, so we went with a more primitive method of banging on the spare tire well with a mallet until we could weld the brace into its correct spot. Either way, you're spare tire isn't going to fit in that tire well anymore.

Greg attached the second connecting rod from the brace to the center point on the diff cover. The purpose of this setup is to keep the suspension centered under stressful conditions. Underneath that center bracket, on the blue plate, you'll see a few adjustment holes. Moving this bell crank unit down or up has a direct influence on how much understeer or oversteer, respectively, you have in the car.

We installed the rear coilovers that mount from the stock upper position inside the trunk down to the new lower control arms. As a note, the spring rate on the rear coilovers is dramatically lower than the fronts, at 225 pounds. This is Griggs' normal rear rate for street-driven, open-track cars. They chose this combination for me instead of the normal 250 pounds that goes with the 750 pounds, so that the car will be on the tight side while I get some more track experience.

The complete Watts link rear suspension sure is pretty, but more importantly, the car handles like a race car in the turns yet drives like a Lincoln on the highway. Well, almost.

I'm not sure who owned this car before me, but based on what was found under the back seat, I'm pretty sure they used to take their horse to McDonald's for coffee. We also found a Daffy Duck figurine, a .38 caliber bullet, and 78 cents in very sticky change.

Once the interior was out of the way, Greg and Shawn cut into the floorboard above the subframe. Shawn also removed the soundproofing around the cut area to allow for a cleaner welding surface.

Greg painted the bars with rust-preventive paint and then laid the 2-inch-square tubing into the subframe. He placed the mounting plate against the rear seat base and then welded them all up. Once the metal cooled, we reinstalled the carpet, with one catch.

The in-floors may fit nicely into the subframe in front of the seats, but behind the front seats, the bar sits above the floor. The best answer is to cut into carpet to allow for them to pop through all the way to the rear seat. If you do this correctly, you can spare any aesthetic problems by hiding the cut part under the bar. If you have rear floor mats, they fit perfectly under the bar, covering the cut area perfectly. This is all a small price to pay for the remarkable response you get from having the in-floors installed. Another positive side effect is less noise. A lot of the creaking I was so familiar with has diminished now that the chassis is stiffer.