I currently have a FMIC, upgraded turbo and a HKS SSQ BOV on my 89 T2. The valve is currently right by the inlet of the throttle body.

Ever since i put my 3" to 4" custom cold intake on my turbo ( i have no AFM because i have a Wolf 3D engine management system) with the filter in the brake duct inlet, i have an extra BOV sound. What do i mean? It sounds like a BOV is going off near my intake AND where my HKS valve is at.

The question is, is this the sound of chatter and air hitting the compressor backward and thus the need for a second BOV right after the compressor outlet?

or

Is this just an echo through the piping from my BOV?

If the descrition ive given isnt good enough, just let me know. So what does everyone think is going on??????

Graham

 

Yeh thats a bit of backspin, it isnt causing too much damage as your blow off valve is removing alot of the excess air but if your compressor wheel is very very sensitive then you should have 2 blow off valves.