Boost creep on tial 38mm

[TurboDSMer]

i have a 20g turbo and all supporting mods. I am running a tial 38mm gate on a VPE O2 housing that routes back into the exhaust. I checked for leaks and found none. I can't figure it out. Also i am running strait wastegate no MBC right now. i have the ~15psi spring in. It will hold 15psi from like 3800 rpm to about 5k then go strait to 17psi until 6k the go to almost 20psi and stay there until i shift at 7k. Thoughts

 

[awdrst]

Did you port the exhaust housing where the old internal wastegate was? I had the same problem on my 20g and some porting in that area helped out with mine.

 

[project_tsi]

Did you port the exhaust housing where the old internal wastegate was? I had the same problem on my 20g and some porting in that area helped out with mine.

I'd assume the same. Properly porting your current turbine housing WG passage will greatly reduce the chance for creeping. Without doing so, your 38mm WG is only as good as the 31 or 34mm passage in the turbine housing, thus still leaving inadequate flow of WG gasses, resulting in creep.

Me, I'm lazy and just prefer to run the WG off the manifold unless its setup like a FP turbine housing w/ a 44mm Vband WG.

 

[TurboDSMer]

I ported it out some, i didn't go crazy like you see on the forced performance turbos like the green and red but i ported out the area so that there is a little bit of the area where the internal flapper door would sit. I am going to see if upping the boost helps and just run a strait 20psi and see if thta fixes it.

 

[awdrst]

Thats fine if you want to go that route but i'd say that it's just masking your problem. The big draw to using a external is the fact that it doesn't boost creep. It shouldn't take that much time to port the hell out of the wastegate passage and then you won't have any creep to worry about.