Just got my 34mm Turbosmart BOVS, not a bad little unit, they seem to open quite quick on 12psi, and you can definately hear them! Half way between stock, and ZX1990s Turbosmart V-Ports i reckon as far as sound goes. Ive got replacement silicone pipes for the intake, but cant get to the clamps behind the condenser, so thats on the to do list.. Outlet i used 34 -> 28mm elbow reducers. Took a bit of trimming but they fit nicely, and will fit better once i get the inlets done with a bit more length.. As much as i know about BOVs? Id say they are a perfect Stock or better replacement..
Pics coming, just waiting to get home before dark to pull the bar off.. hopefully this weekend, and to install a Hicas lock bar, n-power dumps and pipes and my Profec B
Photos You might be able to see they are tight on the turbo pipes, thats where they need about 30mm extra length on the intake side to bring it out further