ok C n P from zpost... also a note from the people asking about damagine the subframe mounts by being too stiff!!!
i had this discussion with VT today..... in short the competition mounts are not solid enough to cause failure of the mount points
heres the info from the man himself....
Regarding stress cracking this is an interesting one. The stresses could come from two areas if the car is solid or near solid mounted.
1) A solid mounted engine will stiffen up the chassis by becoming a reinforcing member. This will increase the torsional stiffness of the car but by doing so you will potentially put massive forces into part of the car that are not designed to take it.
2) A solid or near solid mounted engine will transmit vibration from the engine to the chassis increasing local stresses in the mounting points. We measure vibration using the scale mm/s. This is an industry standard for vibration severity. An engine produces around 10mm/s at idle and up to around 20 to 30mm/s at high RPM. When we measure vibration we aim to get down to around 0.5 to 0.8mm/s in the cabin floor. Even our very stiffest mounts competition mounts would only give around 2 to 3mm/s in the cabin. To put this into perspective the threshold of human perception is around 0.4mm/s. In a building 10mm/s is enough to cause structural damage!. So if an engine were mounted solid there is enough vibration energy produced by the engine to put enormous stresses into the car structure.
So in summary there is not enough vibration transmitted by our mounts to significantly increase the stress in the subframe either by chassis flexing or vibration transmission.
I hope this helps.
Now..... i have to say these mounts are rather impressive..... im PLEASED i have the competition units in the car and im happy with them, i would say however you WILL notice an increased almost like low resonance vibration almost @ idle...
so in summary, these wont damage your mount points, they WILL increase idle NVH and so far from what i can tell the rest of the rev range theirs no real concern area Zub.... your car may be even smoother as mine has the imbalance of a whopping great s/c on one side, (it creates idle vibration)
The mounts are a work of art..... The road versions are more than enough for 99% of the needs, for me i wanted as much motor movement control as im getting certain parts brushing the hood under the extremes of use.... Im almost certain that movement will be stopped with these mounts.....
i Cant wait to get to the track with these on!!!! BTW they are lighter than the stock mount according to my scales..... i opened up one of the mounts also and their rubber piece is much more significant that you think from what you can see.... so i understand how the comp ones wont be causing stress issues...... they are simply not solid enough and can be slightly depressed with you finger even..... the fast road version can be squeezed pretty easily.... the stock ones feel like jelly compared to both!! my stock mounts had 11k miles and its pretty obvious the ast few ks worth of s/c power and track-time has really weakened them.......
if you can chance to open one up they are a very nice design inside, their is no way they can completely come apart!!
VT you killed it with these mounts!!!! phil has been a pleasure to deal with from the off.
