PLEASE HELP!! Any ideas welcome! lol

Its driving me mental trying to work out why the hell my YB wont rev over 5.5k. engine spec below.

Long Stud 200 Block
Siemens 850cc injectors
Bosch 044 pump
Flowed Head
Double valve springs
BD14 inlet cam
BD10 Exhaust Cam
Piper vernier pulley’s
T38 Hybrid Turbo
dizzyless with Coil pack
Anti-lag
P8 with baby board
Airtec 70mm intercooler
10mm Plenum Spacer
Piper cone filter
Fully balanced
Ally flywheel
Gated, baffled sump
All hoses silicone
C57c plugs
Magnecore 10mm leads
Mongoose exhaust


Checked timing 10 times, changed phase sensor (runs nicer now, but wont still wont rev), new plugs, injectors, pump, filter, intercooler and even the pump wiring. Its on the rollers and the fueling looks great. just cant seem to get it to rev right

Its not misfiring, it just dies off lilke a deisel.

its had a lamda fitted to help with the fueling on the road. is there any way the lamda could be changing the ignition timing at those revs and dropping the power?

Trackday next week and I'm going to lose a bet at this rate.

Thanks, Paul