For the past few years I've been running some solid motor mounts that basically look like these
Same material for the tranny mount. So everything that goes on I can literally feel. I can feel a vibration difference in knock from 91 octane to 100 octane.
Now my problem is that ever since I went to these solid mounts I've been having a harsher than normal vibration from 4k+. There isnt any power loss and its directly from the engine and since I'm doing maintenance on my car I thought I'd try to tackle this problem since it's been bugging me for the past 2 years. My wideband isnt showing any dips/spikes at 4k and my SAFC isnt showing any knock either.
Its constant within all 5 gears which makes it unbearable to drive faster than 85 mph in 5th gear. I dont believe anything is loose, I've upgraded/replaced/removed/re-installed most of the exhaust/turbo components within the past 2 years and still the same vibration.
My assumption would be that RAS would help, what should I do?