Quote:
Originally Posted by Dean
Despite what "she" might say, I don't think harder is always better.
Where is Austin when we need him?
I would assume there is some sort of trade off between stiffness and breakage. A little compliance in different directions has got to do something for you or everything would be solid non-compliant stuff for motorsport applications.
Soft mounting is not just about NVH as far as I know, it is also about about a designed wear/failure item/point.
Even on tarmac, there are impacts in non-standard compression/rebound directions as you hit the sides of rumble berms, drop a tire, etc... Those forces have to go somewhere? Metal fatigue is the alternative to rubber fatigue I would think. A worn bushing is easier to replace then welding a cracked/broken sub frame.
Also, If you solid mount an engine or tranny, do you end up having to add weight to reinforce those mounting points and/or use larger hardware to take the added shock load not dissipated in the rubber?
Shock loads break stuff, or so I get the impression. They sure loosen lug nuts with much less apparent effort than static pressure appears to.  |
I'm not an off-road guy, so I don't know what the proven norm is for bushings in rally car applications. I do know that the offroad trophy trucks I've looked underneath have had solid mounts and metal bearings everywhere. They have custom frames and are built like tanks, though.
As a general rule, stiffening bushings/mounts and limiting deflection is a good thing for performance (obviously). However, it does increase the impact force seen by the mating components, which could shorten their lifespan. Whether or not this is anything to be concerned about completely depends on the specific parts & chassis involved.