posted this in the thread i linked to as well, but there's more movement on this thread so it's going in here too:


**DISCLAIMER: what i did in this post was dangerous and probably exceptionally stupid. If anyone decides to attempt to recreate this, they do so entirely outside of my influence or instruction. I'm not liable for any damages that may come from attempting the following activity on your own. if you drive through someone's house, it's your own damn fault.

Just got back in from running the car to 60mph on jackstands in my apartment parking lot. (if my landlord ever finds this i'm probably going yo get evicted on the spot ) here's my findings:

Procedure: jacked up the rear of the car and put it up on jackstands. ended up with about 2 inches of clearance between the tires and the ground. got in the car, turned it on, and slowly accelerated from 0 to 60, holding speed at 20, 30, 40, 50, and 60 for about 15-30 seconds to listen for the sound. shifted 1st-2nd around 2k rpm, 2nd-3rd around 2.5k, and 3rd-4th around 3k.

Safety precautions: Parked the G with a large metal dumpster in front of it to minimize damages if the car were to fall off jackstands. Chocked the front wheels to avoid hitting the dumpster if at all possible.

Conditions: 25* F. sunny. very little wind.

Results: The whistling was present between 40mph up through 60mph. It acted as it does when driving normally, with pitch changing based on speed.

Conclusions: The noise is purely mechanical. wind from movement obviously plays no role in this issue. This eliminates every "bad seal" theory, as well as the "air intake damper" theory. The transmission and the rear diff are both still possible sources.

Notes:
*I stopped at 60mph for safety concerns, but the noise was still at that point, so i don't know where the upper range would have been. I don't think that really matters for this study though, as the point was to replicate without wind.

*VDSC must be turned off before you begin accelerating, otherwise the car will sense that it isn't moving and immediately kill any acceleration.

* Cruise control doesn't work with the rear wheels off the ground. attempting to activate cruse control with the rear up led to a quick acceleration spike followed by an immediate drop in RPMs.

*because of the cruise control not working, i was unable to get out of the car and investigate further where the sound was coming from. I did take a rubber hose with me though, and was able to wrap it around under the car and listen, and the noise was decidedly louder under the car. I was unable to get any further info from pointing the hose one way or the other, unfortunately.

*shifting without moving feels unusual. i had to go through a brief period of learning how to shift again, and burned the hell out of my clutch once.


So, there we have it. anyone have any thoughts?