hey guys i have a 93 r1 with original engine and turbos, but i've got a problem. It is running 0-1 psi up until apx. 4000 rpms. and then only 4-5 psi from there up. (the second turbo). Also when you get up to 2500 rpms. it makes a whooshing sound that sounds like it's coming from up underneth the dash on the passenger side and the noise lasts all the way to redline. Any ideas? I'm thinking vaccum line but i wanted to see if anyone else had this problem.

 

Yeah, vacuum lines, maybe intercooler or turbo hoses, etc.

 

check the rubber coupler between the Y pipe and the upper intercooler pipe, it might have a split in it.

 

Sounds like a loose IC hose...same thing happened on my buddy's supra after we installed his boost controller we forgot to tighten down the IC lines, it makes a big difference