I had full urethane bushings in my last E30, FCABs, and everything in the rear including the diff and it had a bit more vibration but honestly not that bad. It was a DD and was at an HPDE at least once a month all over the southeast. I put about 20k miles a year on that setup and even cruising on the highway was fine. I did notice a bit more buzz at certain speeds from the diff but I had a nice radio and with it even at normal levels I couldn't hear anything. I thought it would be much worse than it really was with everything urethane. |