boost cut off at 4000rpm!

[jesse0880]

when i drive at wot, my car totally drops power at 4000rpm. right before is does, i can hear a big swoosh of air which i believe to be the ATS external waste gate cause i still have the stock bypass vavle. i believe the spring in the waste gate is set at 10 psi. with a td06 turbo, could i really be hitting 10 psi at 4000 psi or could it be fuel cut or something?

[LYR]

with a td06 it is possible that you might be hitting 10pound by 4000, but to me it does sound like it could be more a fuel problem.. either you fuel pressure regulators are not fumping enough(which will require larger throttle body) or it might be a simple fact of running too low a octane fuel.. if the car has been running pretty hard for a while an then, as you say, the waste gate lets go, i'm goin to have to say it's most probably a throttle body enlargement! go talk to a turb. tech in your local area, if you can show him what its doin, an they will advise you what IS actually goin on! oh, an low octane fuel, high outside temps, an not good enough airflow through you mas sensor might be a problem too...got a pod + cold air fitted?? if not...DO IT ASAP.. more power an responsiveness + straight up better all round performance!!!