Dave Sims

There is big whooshing sound lifting off from WOT only under hard boost

Have checked and tightened every hose,replaced the BOV, listened for air leaks checked that the wastegate pipe does not get host when the exhaust does

Any ideas please

Danno

Is the control line to your BOV connected to the intake-manifold after the throttle-plate?

Dave Sims

Danno, thanks for the reply

Traced it back and yes

Also removed pipe from top of valve and at idle it sucks my finger

Ski

I think your BOV is gone. AFter my upgrades I blew mine on the first run,,went to shift and WHOOOSH, almost fluttering sound. Put in new 930 one, problem gone.

Dave Sims

Thanks for the reply. I had a 3 year old stock BOV. I replaced it with a Bailey one - no change. Testing the old one it seemed OK

Dave Sims

Thanks to all that helped. All the testing pointed to an intake leak. And after spending 6 hours it was the intercooler-turbo hose (at the turbo end)
The hose clamp was so loose bubbles did not form when I pressurised the system

I now know every hose and clamp!

Danno

Ah yes, that hose is a bugger, eh? I had a 30mm slit on the back side of that hose on the bottom once. Could see it and all my hose-clamps were tight too. It would only open up when boost built-up to a certain level, then WHHOOoshh, I would lose my boost and the car would start bucking. It was only when I physically removed that hose that I found the cut.