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Bruce, Swamp,
As usual, you've initiated a solid/interesting discussion. This time about shifter wiggle/vibration/rattle/transmission vibration, or whatever you might want to call it. Although I don't have bandwidth participate, I am interested in reading/learning more. I suggest, if I may, that we retain focus on the technical issue.
Although I agree with Bruce's point about the shifter vibration somewhat designed into the product, I find it hard to believe they would want that much of it. It really "seems" a bit extreme although I have not driven a bunch of special purpose cars with such engine outputs. It would seem that the vibration could even get in the way of performance: isn't there a risk of the not being able to grab the shifter quickly/properly when it is moving around that much if you decide to end it and shift up? Also, I don't understand how solid engine mounts would resolve this particular problem at redline (Bruce's suggestion). Shouldn't the engine operating at constant rpm at that point due to the rev limiter kicking in? In that case, what exactly is causing that level of vibration? Would that level of vibration be present, say, if the driver held the throttle steady to maintain engine operation a few hundred rpms below redline? Is this the artifact of some strange interaction between throttle position/driver input and the rev limiter control software? I am assuming the driver input is "maintained" at a high lever than what the computer would allow to prevent an over-rev at those points. And it is possible that the software is reducing throttle to prevent the over-rev, stepping out, the driver input, which causes increase in revs, kicking in, the software taking control again and reducing throttle, and cycle repeating itself in relatively high frequency, and hence the strange vibration. If that is the case, one would think that the software can monitor driver input, determine that it is still at a level that would cause an over-rev, and rather than stepping out, retain control and hold revs steady at redline until it detects a decrease in driver input to the extent that it would not cause increase in revs.
Just a theory...I am basing this theory on the observation that the shifter movement seems to have similar displacement amplitude during the rest of the ride, but not at the high frequency that is observed during rev-limitation. If that is the case, the frequency of the vibration should have nothing to do with how the engine/transmission is mounted while the amplitude might.
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