FD Wastegate bleeding issue?
 

Hey all, I have had an issue plaguing me for a long time. I am now trying to get to the bottom of it. I have an old school 50mm Hks wastegate with a 28-30psi spring in it with side port reference plumbed just after turbo, the top port is plumbed to a Blitz electronic boost controller referenced from just after the turbo as well. I have replaced the solenoid of the boost controller to eliminate that as an issue and it holds air and functions properly. In the past I have had to add shims to the wastegate to reach my target boost of 20-22psi even with the boost controller running, the strange thing is with the EBC turned all the way up that is my limit, I can turn it down and the boost decreases. I should only have to run a small spring with the EBC and be able to reach my target easily? I run a Borg Warner S366 with a large street port 13b. I have recently pulled the wastegate and bench tested the side port, it starts to crack open at 25ish psi which is correct for the spring in it. I reinstalled the wastegate and ran a test from the turbo inlet. This is where the issue comes, the wastegate now bleeds off air from the dump tube almost immediately roughly 10psi or so, I immediately installed it right after the bench test so absolutely nothing is different. I am very confused...is it opening easily as it is now seeing side port pressure, as well as pressure at the plunger? where as on the bench it only had the side port? I originally thought I had too much exhaust back pressure pushing it open, this cant be the case though as it is opening just from my small compressor at 10psi. Any input would be SUPER grateful as this has been driving me nuts. Thanks!

**Update** Removed reference port from turbo to side port of wastegate so was only seeing pressure at plunger and was still coming out dump pipe at low psi from compressor. Could not see if it was lifting plunger or leaking passed somehow. Purchasing new wastegate to see if that fixes it.... dont know what else it could be....

Re: FD Wastegate bleeding issue?
 

I know this is a year late, but it's normal for external wastegates to leak side port air.

Why are you running a 28-30 psi spring when your target boost is 20-22 psi?

Are you sure it's really a 30-pound spring?

Try running it with just a straight line to the wastegate and see what happens.