Sard racing bov


Hi anyone using Sard racing bov? Not the r2d2.
I had one but than the adjusting I'm a bit blur. Only soft and hard. I did try both. But the sound everything just like same.

As the Japanese manual says that when turn to hard the release sound shorter but than I try. Both like the same..
At first I didn't know that cannot over turn the adjust, and I turn few round to hard and few round to soft... Hope I didn't spoil it....

Anyone can help?
Boosting at 1.5bar.
Holding in soft and hard the same.