Well - I saw seen a video of an NR years ago, and it kind of reminds me of the sound - but I do not remember for sure if the sound was so high pitched.
Then again, it is a 15,000rpm V8 for all intents and purposes, so it may be 100% accurate. I ran it against the NC30 just to get some "RC30" / RC40 (NR) pictures and you can hear the V4 compared to the V8/oval V4 distinctly.
It literally screams - maybe like a tiny Ferrari?
I'll post some video sometime.
After the marathon session needed to unlock that one, I am happy to just putter around with the rest of the bikes, and if something else gets unlocked great - (although I heard getting all Gold in Super unlocks the Yoshimura X1..
)