When i'm boosting just under WOT there is a sound coming out of the engine bay.It's almost like a hissing sound.
Could it be a boost leak?

 

could it be your turbo spooling?

 

Probably. Do a boost leak test.

 

I know what a turbo sounds like.

It's something else,i'm going to get a boost leak test done.

 

Sounds like a boost leak to me. I would definitely do a boost leak test.

 

Sounds a lot like a boost leak

 

Yip,3 boost leaks.One on the T-piece tube on the intake manifold going to the boost gauge pipe.One on the lower intercooler pipe silicone piece and the biggest one on the turbo outlet pipe.The previous owner drilled a hole in it and tapped it with a nipple and never closed it.

So now i have to get it logged again and do another power run on the dyno.