DESCRIPTION
Exclusive to Goodwin Racing!
Engineered specifically for the unique requirements of the C Street autocross class. Designed to meet the bumpstop length requirements of the class, with stiffness and ramp rate fine tuned to create a neutral handling balance when paired with the other popular allowed suspension modifications in CS which include Koni Sport shocks, Progress FRONT sway bar, and autocross alignment.
Brian has spent years racing the ND in C Street class testing dozens of rear bumpstop configurations to find what works best. CS presents a unique challenge because you are only allowed to change the front sway bar, and while that is certainly advantageous to do, only being able to go to a stiffer bar at one end of the car makes it really difficult to get the handling balanced with a limited number of things you can adjust within the class rules; you can get a bit of improvement with alignment and adjusting the damping of the Koni Sport shocks, but the real key to getting the handling right with that big front bar is to go stiffer with the rear bumpstops so that when you load up the suspension in a corner the bumpstop effectively increases your rear spring rate.
Until now the fast guys in this class had to piece together their own frankenstein concoction of multiple bumpstops cut to specific lengths to get the right final height and handling balance. Now with Goodwin Racing's rear bumpstop set that DIY experimentation is no longer necessary as our new rear bumpstop set is an all-in-one solution that gets you the class legal length and exact behavior you need.
Kit includes:
2 x 73mm Rear Bumpstops
2 x 7mm Spacers - for use on ND2/3 to increase total bumpstop stack height to 80mm
CS rules limit bumpstops to factory height and NO MORE. ND1 rear bumpstop is 74mm and ND2/3 rear bumpstop is 81mm. We designed these to be 1mm shorter to ensure class legality with no chance of a disqualification. The included spacers cannot be used on ND1 and remain class legal - those spacers are for ND2/3 only.
These bushings are manufactured exclusively for Goodwin Racing by SuperPro, utilizing their proprietary engineering grade polyurethane formula with unique material properties. SuperPro Polyurethane is a special elastomer based material which gives an extremely durable bumpstop that outperforms and outlasts other common foam bumptop materials.
BRIAN'S THOUGHTS. These are NOT for everyone, and they may not be for you even if you run SCCA CS every weekend. I wanted the car to rotate despite our usual CS mods of big front sway bar and KONI SPORT shocks and stock springs. I use half a stock bumpstop at front, these in the rear. YOU MAY SPIN THE CAR the first event you drive with these, I had to LEARN TO DRIVE it with hard rear stops. It was worth it to me because the car is a lot faster and better balanced (normally BIG front sway bar for CS class, only one bar upgrade allowed per CS rules, means terrible understeer). I have the front KONI SHOCKS in a softer adjustment from full soft to perhaps one turn from full soft, and rear KONI ARE FULL HARD so the car 'jacks down' and sits on these stops in long slaloms, at which point it goes a few more miles per hour through the slalom because these balance the roll resistance of the big front Progress Sway bar. YES, in daily driving when not racing these feel pretty stiff at the rear if you hit a speedbump or pothole serious enough to get deep into the stops.