Project Rolling Thunder: Part 4

The best figure for the stock brakes from 60 mph was 127 ft, and the worst was 131. As we waited to see how much better the StopTech system would be, Ruiz went to work replacing Thunder's two-wheel-drive front stock stoppers. As it turned out, the best number StopTech provided was 127; however, it should be noted, that after seven full-on mash-the-pedal panic brakes, stopping distances were basically unchanged. Runs five, six, and seven with the StopTechs showed 127-ish consistently. We take this as proof of the heat-dissipation support the StopTech brakes provide over stock, a clear advantage when heavy-load towing and hauling come into play. Another advantage we found with the StopTech brakes had to do with pedal feel. Motor Trend Senior Road-Test Editor Chris Walton commented the StopTech setup felt firmer and more confident.

Keep in mind when comparing Ford and StopTech numbers that sticky tires work wonders. Goodyear Eagle F-1s are road grabbers and a significant factor in why the truck stopped with large, Mercedes-like results with both systems. Also keep in mind these were prototype brakes designed just for Thunder, adapted from the 4x4 system--they were experimental. We're told StopTech has since done some reengineering and came up with what it considers a much better design for the two-wheel Expeditions because of the piston size.

While the SVT wheels created the first problem for StopTech because of offset issues, it figured out a way around them. Stock wheels are hard to match with aftermarket brakes for the same reason, and the OZs were probably a better choice for StopTech's original idea. However, the thinner design of the six-piston caliper over the four-piston allowed the necessary clearance to save the SVTs. Due to further development, StopTech will not market the six-piston design for two-wheel-drive Expeditions until mid-summer, though the four-piston is currently available.

Any time an undertaking of this magnitude is launched, it's good to know that anticipated and unanticipated challenges will happen. While this fact was ever evident in development, the Truck Trend/StopTech relationship with Thunder was a reasonably successful one, albeit a tad confusing. In the end, our Thunder was given a brake system we're happy with, thanks to the stamina of the StopTech crew. And it doesn't hurt that we could help StopTech in the creation of a better-than-stock system for other two-wheel-drive Expedition owners.