Universal exhaust mounts POWERFLEX caused excessive vibration

[Archtects]

Bought 2x Powerflex universal exhaust mounts EXH 008, in red. They turned up a tried them, drilled the holes 11mm fitted, zip tied all good.

Gave it a little test but it feels way to shaky. The car feels very shaky and if I stop and drop bellow the 1k rev mark it really shakes. It feels like it's the back, not the engine.

Anyone had the issue? Going to take them off and drill the holes bigger I think. Maybe it's to tight? Or is it supposed to feel so shaky.

 

[Archtects]

I've drilled the holes much bigger. I've tried to match them to the size of the oem holes and then wiggled the drill a bit. Feels better still shaky, but I expected some vibration as they are stiffer. Should be fine