Just set up the torque app to monitor my boost. Had the car out today. Held at 2000 revs then floored it to 3000 revs and it was peaking between 10 and 11.5 psi which i expect it should. Once it had peaked it seemed to drop off dramatically and didnt hold a consistent figure (around the 5/6 mark.)

Any ideas what this could be? Should i be concerned?

Edited 19 October, 201510 yr by Mcinvrs

These turbos do run our of puff a little at top end and so will drop off. You may need to be slightly concerned if it drops notably below what the ecu is requesting. As you're making peak boost (standard car isnt it?) you shouldn't be overly concerned. If it is tailing off significantly below specified it's likely to be a weakening actuator, the spring gets weak and/or diaphragm inside can perish, assuming that is there are no boost leaks and such...

Yeah its standard. Everything feels sound. Just thought the boost should drop a little and hold? Think a mechanical gauge is in order lol

I suppose it depends how much it's tailing off, logging block 115 in vcds will tell you a lot. It won't hold at peak boost but it should roughly follow specified so like I say it's about how much it drops below that really. An old tired actuator is quite common,the way they're positioned they gather a lot of dust and grime. When the spring gets a little weak they struggle to overcome exhaust gas pressures at the top end to close again to maintain boost. So I don't think you have a major issue by any means but if it's dropping off too much that could well be it. Might be worth getting a smoke test as a general test of boost health for peace of mind and to rule out leaks.

If it drives ok, don't worry too much, it's easy to get paranoid about stuff.