Never heard that with mine, been up to those speeds couple of times, but never heard anything unusual. May have something to do with ring-pinion gears not meshing properly . Does it do it when decelerating at different speeds as well !

 

0 to 120 all is well but past 120 it starts getting loud. I'm kinda worried about pushing it past 130 to see if the noise gets louder.

 

I dobt any service manager will want to go for a ride over the 120 mph I know I wouldn't want too. I would suggest changing the rear gear oil with some high quality syn stuff. Just for starters. That way at least you will know thats all good. Please don't drive at those speeds where anything can walk out if front of you. Just sayin

 

There are ways of going 120 mph while standing still, it's called a dynamometer.

"I wanna go fast"

 

I can dyno the car and check out the noise at the same time.

 

Also- if you dyno the car and don't hear the noise, then maybe it is a wind or air-leak issue.

I wish I had a place I could legally drive over 100 often!