Rear Shock Mount

[Infinity]

Hey guys, I need your help. I have a packed rear suspension( so does everyone !!). The position that has been left for the shock mount have been shorted down to two options. One involves mounting of the spring mount directly on the Engine mount. Does it help in damping the engine vibration? If it does, then does the vibration of engine effect the wheel movement? Is it of any advantage.

[Infinity]

Hey guys, I need your help. I have a packed rear suspension( so does everyone !!). The position that has been left for the shock mount have been shorted down to two options. One involves mounting of the spring mount directly on the Engine mount. Does it help in damping the engine vibration? If it does, then does the vibration of engine effect the wheel movement? Is it of any advantage.

[Chris Allbee]

Well, if you mount to the engine mounts make sure you take into account the thermal expansion of the motor and how it will affect your cross weights. If you don't the judges will call you stupid. As for damping engine vibrations...if your chassis flexes enough from engine vibrations to move the damper, then you have bigger issues to deal with.

[Infinity]

What thermal expansion?? which motor are u talking about?... Damping engine vibrations....exactly i was talking about the same thing....how much do u think will the mount vibrate? i dont think it will be enough to effect the rocker? What i your say?

[Chris Allbee]

I'm talking about the thermal expansion that occurs when physical objects get hot, unless you have managed to conceive of an engine that has an operating temperature of 72 degF. The motor (engine, power unit, etc.) is an F4i in our case.

Now to damping your engine vibrations with your suspension dampers (the ones attached to the rockers or bell cranks). Have you checked to see what the natural frequency is of your unsprung assembly at any given corner of the vehicle? Once you have, check the frequency of the motor vibrations. Now that you have that...how much do the two of them overlap if at all?

Back to the chassis comment I made, and I will repeat it: If your engine vibrations are causing visible movement of your suspension YOU NEED A STIFFER FRAME! Otherwise, if the dampers aren't moving due to engine vibrations, they aren't damping anything....its a reactive damper, it HAS to move to damp anything.