Crazy boost creep with external gate

[Loewen21]

Hey guys just installed my evo 16g today and now im getting insane boost creep. I know its not the boost controller because i checked by running the line to the wastegate just from the j-pipe without the boost controller and got the same effect. Im running a tial 38mm right now mounted on the 02 housing. It will hold boost fine until 4500 rpms, at which point it will begin to creep or spike uncontrollably. Could this be because of my 3" 02 housing and downpipe? Or is the wastegate path too restricted?

 

[Pube Stache]

What spring is in the wastegate?

 

[autronicDSM]

Did you port the wastegate hole after removing the flapper? You should, you can only flow so much gas as the smallest hole in the path.

 

[bushy]

you have to port the wastegate opening on the turbine housing. putting an external gate does you no good on the o2 housing with a restrictive wastegate outlet on the turbo.l

 

[tonster]

Make sure the wastegate is opening all the way. Look to see if the vacuum line running to the wastegate does not have any tears in it. Also make sure you have the vacuum fitting on there is tight.

 

[Loewen21]

I know for sure it's opening all the way as its just as loud if not louder than before (atmospheric dump ). I'm pretty sure its just the restrictive outlet coupled with my 3" 02 housing so that too much of the gas is flowing through that path and not out the wastegate. If that makes sense.