For those with HKS silent Hi-power...

For those with HKS Silent Hi-power axlebacks... How much louder did they get over time? How long did the break-in take?

Installed mine yesterday. I know there's 'silent' in the name... and it's REALLY quiet. Very different sounding than the youtube vids of other K13 & E12 1.6's cars.
Attachment 6013

I've had mine for over a year and it's no louder than the day I installed it. If you're looking for a bit more braaap you may want to look into removing the resonator and second cat.