Well...
I put a JB3 in my car and now I have 383hp (instead of 306hp, original).
The original presure intake is 8,8 PSI in the 135i, but now I have 13-15 PSI.
So the stock valves are a little poor and slow for these presures.
More than performance, a bad diverter valve can damage the turbo. I my case, I think I have a leak (escape) when I press the trottle.
Sorry my english is poor to explain better...
