Powerflex Urethane Track-Series Rear Subframe Inserts - E46 M3, E85 Z4M
A complete 8 piece Aggressive Street/Track Kit to stiffen your rear subframe mounts without doing a full replacement.
Reinforce your E46 M3 or MZ4's failure prone rear subframe bushing/mounts WITHOUT having to remove or do a full bushing replacement!
These amazing and clever polyurethane inserts install on both sides of your stock BMW rear subframe bushings, filling the empty voids in the bushing to reduce bushing deflection, increase bushing rigidity and longevity, improve cornering and improve rear end stability. And with Powerflex's Black Series urethane company, which has a stiffer 95A durometer polyurethane, you'll firm up the stock bushings as much as possible for aggressive street and track driving. Perhaps best of all, they install far easier and in MUCH less time than a full subframe bushing overhaul.
These inserts are specifically designed to work with BMW factory subframe bushing part numbers 33312283573 (33 31 2 283 573), 33312283574 (33 31 2 283 574), and 33312283419 (33 31 2 283 419) and are guaranteed to fit these original BMW subframe bushings. If your car has aftermarket subframe bushings, these inserts will most likely not work, as the inserts are molded to match the factory voids perfectly.
If your stock E46 M3 or '06-'08 Z4 M rear subframe bushings are still in good (or new) shape, these Powerflex Bushing Inserts are an ingenious way to protect and improve them! You don't need to remove the bushings from the subframe to install these inserts, making install a breeze.
This is our Aggressive Street/Track Subframe Bushing Insert Kit which uses Powerflex's 95A durometer "Black Series" urethane, which is firmer than the yellow 70A durometer standard "street" compound, making them ideal for aggressive street driving, HPDE, driving schools, or other track driving. These are also available in the softer Yellow compound, which is appropriate for standard street driving.
E46 (01-06) > M3
E85 / E86 (06-08) > Z4 M