HX40 boost creep with BEP housing

[enasnitsi]

Just got my car up and running and I'm having a bad problem with creep. I just installed a new punishment o2 housing and a tial 38mm MVS wastegate, external dump. I have a 20psi spring in it and it will boost over 35psi by 6500. I tried porting the exhaust housing but it didn't affect it at all. I have the wastegate vacuum port directly to the compressor cover. Not sure what else I can check. Already checked boost leaks and exhaust leaks. Wastegate does open.

 

[JusMX141]

http://www.dsmtuners.com/forums/turbo-system-tech/388622-anyone-else-had-hx40-creep-issues.html

 

[Boostdriven]

It's possible that your 20 psi spring is coil binding not allowing the valve to open all the way to bypass enough exhaust flow to maintain steady boost. Bep bolt on housing is fairly small so it need a good bypass port to maintain lower boost levels. Take your wastegate off and put pressure to it with shop air and see how far it actually opens and at what psi. What you can do is try to use a smaller spring and then use a manual boost controller to up the boost.

 

[enasnitsi]

I can try a smaller spring or I'll just use a boost controller and set it to 30 and see if it holds. Was hoping to get a base tune at 20psi. Not sure how that link helps.