Hey Guys,
I have a abit of a problem with inconsistant boost in my mkII T, ive had a custom tune done and it pulled 333 rwhp @8psi, ive changed my bov to a turbosmart dual port and done the usaul other little bits and pieces, pod filter, cat, centre mufflers etc..the problem is sometimes the boost comes on really hard but other times it seems to be struggling and very hesitant? I used to do the boost solinoid maintenance which seemed to make it alot better, but i decided to get rid of it and go with a turbosmart boost controller, hoping it would eliminate the prob all together, had it retuned and it had 10hp less than before, the boost is still inconsistant, it seems to come on abit harder down low sometimes but tapers off top end?? my tuner doesnt seemed to phased as it probably doesnt do the inconsistant/hesitant thing on the dyno . Just wondering if anyone has had the same prob, and if so what is the solution, was thinking maybe its the acuator???..PLEASE HELP!,,,its doing my f*#king head in lol

Get it checked.. Could be over boost, detonation sensor kicking in as safety measure...
Check plug gap ?? It maybe blowing the spark out..

Sounds to me like a wastegate problem.

YEP even broken cat...Intermittent faults can be tricky to trace..
Can even be BOV ..
Intermittent leak in piping etc...

Thanks for the replies, its really doing my head in, think i might replace my wastegate actuator with one that opens at a minimum of 12psi, seen them on ebay for 170 heard its a real s**t of a job though.......hope it fixes the problem!!

Check tune.. Or at least check fault codes etc..
It could be engine computer self protecting itself
from detonation etc..

i think you have answered your own question, some people get lucky with wastegate springs, and some dont...

the lagginess you feel is spring creep, it takes a little longer to spool up cos some of the gas is getting bled out of the wastegate instead of spinning the turbine.

same thing is happening top end, the spring isnt strong enough to hold the wastegat shut so boost just forces it open, and out the exhaust it goes....

an upgraded actuator will fix this