TMS solid mount kits will hold up to the abuse that a powerful, high revving race motor will induce. The main benefit is that they reduce the torque and power lost from rubber mounting movement. Rubber mounts absorb the energy and vibrations produced from the torque of the motor. By not allowing that motion and energy to be absorbed, more power is transmitted faster. The solid engine mounts locate the engine in the original orientation, but 5mm lower, and the transmission mounts are 1mm lower than the original mounts and are also located in the original orientation. This lowers the cars center of gravity and improves the overall handling of the car. Solid mounting kits should be used for race only applications. These are the exact mounts used our SPEED World Challenge race cars. Subframe reinforcement kits are highly recommended to go along with this kit to reduce the risk of damage to the subframe. We highly recommend using the transmission and engine mounts together and installing this as a complete kit. Mixing a rubber mount with a metal mount will cause undue stress on the mouting points. This kit fits all E36 and E46 6 cylinder models.