|Using a new component scale and an assembly development of the proven architecture in all WEVO Semi Solid (SS) mounts, they have created the WEVO 997 SS Engine Mount. This Engine Mount is a simple and easy bolt-in replacement for the more compliant factory hydro elastic unit.
The WEVO 997 SS Engine Mount is designed to offer more precise control of the drivetrain mass. The drivetrain in a Porsche is independently suspended from the sprung mass of the car via the compliance in the engine and transmission mounts. This drivetrain assembly represents approximately 25% of the sprung weight of the car. The opportunity for forces to move the drivetrain comes from many inputs, such as the torque reaction of vehicle acceleration loads, the bumps and variations in the road surface and the lateral forces created in cornering and braking. That degree of independent movement of the drivetrain is responsible for some of the “sloppy" feeling that is evident when the performance envelope of the vehicle is explored. The higher the forces, the higher the deflections in the hydro-elastic mounts, therefore the deflections and movement of the drivetrain mass begin to operate out of phase with the movement of the car as a whole. For Racing the factory eliminate the hydro elastic mounts and install solid engine mount positions – marrying together the mass of the drivetrain and the sprung mass of the car. While solid mounts might be considered a conventional wisdom for a race car, this practice has an enormous impact on NVH (Noise Vibration Harshness) making it totally impractical for a street driven car.
Like all deviations from the original design, there is some compromise. In this case the compromise is the potential for extra noise and vibration to heard and felt in the passenger compartment. Testing has indicated that the change in NVH is a fair exchange for the performance improvement. A tighter feeling chassis, one with quicker left- right response, more predictable gear change precision and stability under braking. In essence, if you have modified your car in any way, loud exhaust, aftermarket suspension, lightweight seats, lightweight interior -- any of these systems are just as likely to have increased the NVH quota for your car and the WEVO 997 SS Engine Mounts might be a somewhat transparent addition to your tuning regiment in terms of NVH.
Technical Note: The M12 nut on the Engine Mount stud should be tightened to 60 ft/lbs or 83 Nm. The M8 hardware should be tightened to 18 ft/lbs or 25 Nm using the original arrangement of washer and nut.