greenone

Anyone have any idea what kind of boost level i should be running on an ecutek 3 remap on a 99 uk car , i have a vf35 and a front mount ,i ported the exhaust headers mildly after the last map, Problem is when i give it beans the turbo starts chattering and the knocklink lights up ! i have put a gauge on and it is running 1.5 bar . This too high ? it only lights up when the turbo makes this high pitched chattering noise , it does it everytime in 4th and 5th occasionally in 3rd never 1st or 2nd , could this be a boost leak ? or just overboost ? . i took it on m/way and tried putting my foot down in 5th and the gauge didn`t go past 1.3 bar and lit up the knocklink ! any help would be greatly appreciated cheers