So I'm having some pretty bad boost creep...I have a 6 psi but till boost to 15 or even 18..its s d16z6 turbo...before with the ebay wastegate it ever boost creep but with the 39mm presison wastegate it started...do you think because I have a 38mm manifold and the gate is a 39mm it's making it over boost?

 

6 psi spring? Creeps to 15 or 18psi? What's your setup?

 

So yes I have a 6 psi spring in it, and it boost up to 15psi even 20psi at times...if I give it WOT it will boost to 15 or 16 and even off there...but I cant do a 3rd gear pull because it will over boost to 20...I have noticed the springs are super stiff...its a presison 39mm gate, the 6psi spring seems stiffer then my 9 pound spring that was in the ebay gate

 

What is your full setup? Turbo/manifold, etc? Boost by gear? Electronic or manual boost control? More info needed. Sounds like you just need a heavier gate spring.

 

Set up
D16z6 vitra build (speedfatory rods)

.48/50 turbo with log style manifold
manual boost controller
S300
the presison 39mm wastegate came with a bunch of springs...I am tuned up too 18 psi so I put just the springs to make 15 psi with the boost controller turned all the way down..which was super hard to put the springs in..it boosted well over 20 psi...so then I put just the 6 psi spring with out the boost controller and it over boosted to 20 psi! I'm like what the F...so then I reinstalled the boost controller and it will even out at 15 psi if going from 2nd to 3rd WOT, but if I start from 3rd and do a pull it will chill at 15 for a few secs then I'll creep up to 20 psi and back to 15...and the wastegate sounds like its fluttering, the ebay gate didnt do this at all..just wanted to upgrade...the springs all seem super still...even the 6 psi spring feels stiffer then the ebay 9 psi spring...the reason why I upgraded gates is because I was loosing boost at high RPM it will not hold boost...I'll from like 10 psi by 7000 rpm...now its holding but its OVER boosting lol..but from 2nd to 3rd I'll hold at 15...I am afraid to turn the controller up or I'll hit higher the 20 just to retain the psi I want it to be...I taking it apart to see if the diagram was pinched but its not

 

What boost controller you using?

 

Looking it over so far, sounds like you've gotta figure out what springs are which. Overboosting- the gate isn't opening when it should; i.e. spring rate, bad vac location, etc.. Not going to AT LEAST expected range- opening too soon; spring rate, diaphragm, etc.. Bad boost controller could be a culprit here, or the springs need to be verified properly. How about the vacuum source? Where does the vac line run from; compressor housing or intake mani?

 

Bypass the boost controller and see if the problem is still there,nothing you have should be causing this issue

 

Also, where are you vacuum lines routed for your boost gauge and wastegate?

 

Pinched diaphragm???

 

OP did you get this sorted out? I’m curious as to what you found. I had a new in the box tial 38mm with a 13psi spring. I was constantly spiking 18-20 psi at first. I removed my boost controller, and things settled down but was still spiking hard at higher RPM. I too am running a log manifold. After a couple miles it’s like my spiking issues are gone. Not sure if my wastegate just needed to “break in” if that’s a thing or not, but it was rough at first, but now it’s staying pretty constant 14.5 about all the way out.