I have a Almost brand new Tial Q Bov in purple. I currently have this on my Jetski but after testing different spring pressures, my ski doesn’t make enough vacuum at idle for this to work properly. There is not a single scratch on this but I already had the flange welded down so you will need one of those.
I purchased this from STM at there Dyno Day this year.
There whole chart is Based off vac at idle. Yes, you are correct but they tell you to size it up according to there specs. I am repeating what they told me.