I have a 97 Catalunya uk turbo.

current mods

HKS hiper full system including de cat downpipe.
HKS inductiond kit
Bailey Dumpvalve

so not much . Have been running like this fine for 6 month anyway now i am getting a squeeling noise when the car boosts up around 3500 rpmm and gets worse as gets higher . It sounds like it is comming from directly behind the dash area sometimes and other than that under the bonnet. has anyone here ever had that or a similar problem . Car seems to run fine but just doesnt sound healthy at all and dont wanna push car cause might be doing damage .

car has done 80k miles and allways been service on time by subaru .

any sugestions

 

Sounds like you've maybe got a hose leaking air from somewhere.I would check all the air hoses for security and check meticulously for any splits(could be tiny),i would then check the dumpvalve diaphragm isn't leaking.

Hopefully something simple!

 

sorry to be ignorant but what is the dumpvalve diaphram i didnt fit it it came with the car.

 

Its the opening and closing part of the valve inside the actual housing