I'm noticing a def lag in psi when spooling up, maybe 8psi but haven't tested it yet for a leak, that this weekends project. But have noticed while spooling on the stock 04 plastic BOV, when it blows off we all know you get the "pshh" sound, but during spool I'm hearing a "ssshhhhhhhhh" sound from the BOV like its dumping while trying to build boost, is this common? Crappy Evo 8 BOVs?

 

Take the BOV off and test it on a bench with a pump or do a boost leak test. Either method will let you know if you're BOV/DV is leaking. It's generally a good idea to get the Evo 9/ JDM BOV sooner than later, it'll save you headaches down the road.

 

Thanx man

 

the stock evo 8 diverter is pretty bad.

 

check the BOV that is the main problem.

 

boost leak test

 

and probably common sense but check all intercooler pipes and couplers and make sure ur intercooler itself isnt leaking

 

I had that same type of sound and just tested mine, turns out one of the clamps was cutting into the Upper IC pipe hose and had a real bad leak. Another thing I noticed when I had 25psi going into the car with my synapse DV hooked up to the UICP I could put my hand over the side on the DV that goes into the intake and after like 30 seconds it would blow off and let all the air out does that mean it has a small leak?

 

Maybe throttle body seals? I had a major leak there in the past. Goodluck with the fix

 

boost leak test, ditch the plastic 8 diverter asap. dont be surprised if its throttle body seals. and take a few minutes to look under the car that intercooler couplers make sure theyre tight. doesnt take much to blow off if they arent tight and positioned right