I'd believe that. I had almost zero vibration with my links set to -5. Did you set -6 front and -7 back?
Yes -6 Front -7 rear. Rear camber is around 2.5°. The Mountain Pass trailing arm adjustment got it to 2.2°. Toe was adjustable to whatever you want, I’m sure the factory arm too, but the Mountain Pass arms ditch the rubber bushings. Front does have an OEM eccentric camber adjust -1.2° was the max setting. The factory front toe was pretty bad. The tires are quieter now that’s it’s set correctly.
It really sounds like a “motor mount” issue that was discussed in this thread or a similar thread.
I think it’s more likely electrical resonance of some sort. F’d inverters, motor tolerance build up, etc. it is just shite, whatever it is.
I think if it was that I’d expect a big difference between Plaid vs LR since I’d expect the resonance would likely be quite different.
Thats what I did, check out Vibration on hard acceleration where you can find the video from inside, its not plaid but the mechanics are most likely the same. The thing I suspect which is also kinda confirmed with this thread is that on hard acceleration the axles bend to an angle where its running off center so lowering the car with the links helps to mitigate the problem. The real issue I suspect is with the big motor mount (passenger side) , its just too soft, not sure if its different in Plaid but definatelly due to its softness it raises the engine and driveshafts with it making the angle unacceptable.
The Refresh vibration doesn’t happen on hard acceleration. Only on slight acceleration on a narrow range in speed. Some sort of resonance. Maybe they did stiffen the motor mounts and now we have this new vibration coupled to the body.
Right, as someone who's had the shudder under hard acceleration and has the vibration, they are completely different. The shudder you can actually hear too.
Possibly they did stiffen it, would be interesting to know the numbers from the rubber and confront it with the previous models versions.
You mean part numbers? Chances are the mount is different since they changed the motor.
Each rubber bit in the bushings has numbers on them like +17 etc, I think thats stiffness. For reference look at the image, thats the old revision driver side motor mount for pre lift S. It has values between +15 and +17, whereas new revision has +21 to +22.
I wonder if with the softer bushing the motor was bouncing under load. Now with the stiffer bushing the swing is much smaller or it’s coupling another vibration to the body. I suspect it’s still bouncing, just a lot less. It takes time for the bushings to soften up. Because if it was a coupling issue newer bushings would probably be worse.
I think you are right with the loop bit, bad axle makes more vibration, under load old soft bushing cannot damp it so the axle getting worse, new bushing mitigate that to some extent, but at the point people complain about the vibration its too late to just change the bushing so new axles is a must.
