Not quite accurate, its a Turbo technics turbo as per the S242 that you lot over the pond seem to love,
RT330 on the Revo software is absolutly fine, Revo have commented on the noise essentially the noise isnt surging its the prevention of surging but the bangwagon has now been created
It’s not surge it’s how the boost is controlled. If the Throttle body opens and closes at a very fast rate to stop over boost then you may see surging issues. This happens at around 3-4k rpm which is when your running peak boost. (
https://www.fiestastforum.com/threads/revo-rt330-surge.19698/ )
Which is something I can only assume the US tuners (that turned up the Boost even further) failed to control correctly, Other than this "issue" in the US, I have seen/heard of no issues with this turbo in the UK running the Revo Software,