Billy Johnson, the most successful driver of all time in the IMSA Continental Tire Championship and a longtime Mustang enthusiast, recently reviewed our S550 Mustang Ultimate Stop-the-Hop package for MotoIQ.
“First iterations of new technologies are rarely flawless. When the Mustang ditched the solid axle in 2015 in favor of a 21st century Independent Rear Suspension, it transformed into a modern-day sports car with greatly improved ride quality and handling dynamics. Unfortunately, the new diff and subframe are mounted with soft, compliant rubber bushings that cause a significant wheel hop when launching the car and unwanted toe changes in corners. This affects drag and road racers alike. In order to eliminate these issues, we tested Steeda Autosport’s Ultimate ‘Stop the Hop’ Package and Adjustable Differential Bushing Insert System.”
“The changes from the Steeda Autosports Ultimate “Stop the Hop” Package and Adjustable Differential Bushing Insert System were immediately noticeable the first time I gently released the clutch to get the car rolling. The drivetrain is far more responsive, immediate and eager to leave the line from a stop than before, even under normal driving conditions. ”
“We took our Mustang to Homestead-Miami Speedway to see what effect increasing the bushing stiffness had. Wheel hop is virtually eliminated and the rear of the car no longer feels like it’s going to drop out and fall off the back of the car when launching, doing a burnout, or even a 180-degree U-turn. When the rear tires do lose traction, the breakaway is smooth and does not upset the chassis.
We were impressed with the improved precision on track. In the corners, the rear of the car feels more responsive, predictable, and ‘in-phase’ with the front of the car. At corner entry, the rear now takes ‘a set’ in the corner at the same time as the front and carves through the corner without lagging behind due to deflecting subframe bushings. On throttle, the rear of the car is a lot sharper and feels as if the rear spring rates are stiffer, but rear grip was actually increased slightly from turn-in, mid-corner, and track-out.”
“Overall, we were very impressed with Steeda Autosports’s Ultimate “Stop the Hop” Package and Adjustable Differential Bushing Insert System in eliminating wheel hop and greatly improving the drivetrain response and handling of our 2016 Mustang. We feel that the Mustang should have been like this from the factory since there is virtually no increase in NVH, but the car is substantially more responsive and precise than before. We highly recommend installing these components for any drag racer, road racer, or your average driving enthusiast for the daily driver due to the significant improvements with zero downsides.”
Head over to MotoIQ for the full Stop the Hop IRS Anti Wheel-Hop review along with Billy’s review on our Adjustable Differential Bushing Insert System and S550 Clutch Spring components for 2015-2017 Ford Mustangs.
MotoIQ is the premier online tech magazine for the serious automotive performance enthusiast and racer.
About Billy Johnson
Billy Johnson is an American professional race car driver competing in the World Endurance Championship (WEC) for Ford Chip Ganassi Racing in the #66 Ford GT and the 2016 IMSA Continental Tire Sports Car Challenge GS champion for Ford/Multimatic Motorsports in the #15 Ford Performance Shelby GT350R-C with co-driver Scott Maxwell.
With 23 wins to his name, Billy is the winningest driver in CTSCC history. In addition, Billy has multiple GT class podium finishes for Turner Motorsports, driving the BMW M3 in the IMSA GTD Class.
Johnson is a test driver for Multimatic and Ford Performance and helped develop the LeMans winning Ford GT racecar, Championship winning Shelby GT350R-C, Mustang GT4, FP350S racecars, as well as street cars including the GT350, GT350R, and Ford GT.