Hi guys! I am from Singapore. Owing to the few number of FD's we have here (less than 10 last count) no one seems to be able to fix a problem I have with my turbos. Sometimes when I run thorugh the gears, after a gearshift up my boost drops to 0.2 bar (around 3psi) and when I release the throttle there is a strange "horn-like" sound coming out of my blow-off!

I have asked a few workshops for help, all they could ask me to do was to go single. I believe the problem doesn't lie with the turbos itself. I have checked the vacuum hoses and couldn't find anything.

Any advice?

Thanks a lot!