I agree with Michael as bracing needs to be the first thing addressed. As for urethane, my suggestion is to get the urethane for the front and leave the rear alone for now if you are on a budget. Putting all urethane on the rear introduces problems. Read the following quote taken directly from Maximum Motorsports' site and you'll get a better picture.
Quote:
Wheel rate refers to the rate of roll stiffness as measured at the wheel. Total wheel rate is the sum of the swaybar wheel rate, the wheel rate of the springs, and the wheel rate of any suspension binding (restriction of movement).
Most aftermarket control arms use bushing designs which actually cause an increase in suspension bind.
To analyze the geometry involved, Maximum Motorsports used a full scale mock up of the rear suspension. When we tested other aftermarket control arms that had hard urethane bushings at each end, we found they increased the wheel rate by 400%. As little as a 10% change in wheel rate can noticeably affect the handling balance of the car.
So why does the wheel rate increase? In a 4-link suspension design, the control arms do not simply pivot, they also move sideways in an angular motion. If that angular motion is restricted because of a poor bushing design, the suspension will bind up. That binding increases wheel rate which in turn causes unpredictable performance – not to mention damage to the torque boxes.
In short, there are alternatives such as the rear control arms from MM. If it were mine, when I got the money I'd get a set of the FRPP HD upper control arms and a quality set of non-binding lowers before you waste time having to knock (or burn) out all of those rubber bushings, which is a monsterous PITA, and replacing them with an inferior functioning product. IMHO
) and the car doesn't even jiggle over a bump - goes over them and that's it.
