RPM trouble

[New s13 owner]

I bought a 1990 s13 4 days ago.
When i hit 4500rpm the engine stops to pull and it makes a winding noise, allmost like a slack generator belt.
The turbo is 1,5 years old, but the car has only been driven 1000km (600miles) the last two years. All the hoses looks ok. The car is equipped with a intercooler and is chip-tuned to about 200hp.

Any sugestions what`s wrong?
Pleace help me out

[TWAN]

Sounds like you have a boost leak. Check all your couplings and vacume lines.

[Warped]

What turbo do you have? and is it still a SOHC engine or was it swapped for the DOHC?

[New s13 owner]

What turbo do you have? and is it still a SOHC engine or was it swapped for the DOHC?

It is a CA18DET engine with a standard turbo.

[New s13 owner]

Sounds like you have a boost leak. Check all your couplings and vacume lines.

That was I belewed at first, but everything looks like it is brand new.

Im considering if its a gasket or someting in the turbo that is stuck, since the car have been standig still for allmost 2 years. (eccept for a trip to the store once a month.)

This is my first turbo equipped car, so Im completely GREEN when it comes to TURBOS.

[Warped]

you may have a bad waste gate. or the blow off valve opening way too soon.