boost control problem

[gsx4357]

i know this has been posted many times before and i read all the threads and tried almost all the suggestions...my problem is i have uncontrolled boost...goes straight to 20 psi+...i have a hallman MBC that routes straight into the cockpit of the car...it used to stop at 16 psi and now its not working properly...i got a 16g turbo with a internal wastegate and its relatively new...i mean less than 10 thousand miles...at first when i got the MBC it wouldn't raise boost...and i saw somewhere (which i regret) that if you cut the spring it could help...it did for a bit then started messing up...now i tried replacing the spring around 4 or 5 times and still nothing progressed...i don't know if the spring is too weak or what...i recently rerouted the MBC to the j-pipe because it used to be T'ed to a vacuum line from the head and honestly seemed to do better then...its still boosting straight to 20 or plus boost...should i try a different boost controller or should i try a stronger spring or what? the spring i put in it now is long but kind of weak IMO... please give me some suggestions...it really extremely irritating not being able to drive like i want without it hitting fuel cut all the time...any help is greatly appreciated

also forgot to mention i have a megan racing o2 housing if that makes any difference

 

[DROPthatCLUTCH]

I'm having the same problem... Happened after the FMIC install when I T'd into the BOV line, so tomorrow I'm tapping the j-pipe.
If that doesn't work, I'll be in the same position you are right now so I'm keeping my eye on this thread for sure.

I was thinking it might just be a boost spike, but I'm not positive on whether the boost drops back down to where it's set, I'm off the gas as soon as it touches 20psi.

Maybe the long routing of vac. line going into the cockpit can cause somewhat of a "lag" causing the WG actuator to respond late causing the spike. Maybe just run your controller under the hood with minimal amount of line and see if anything changes?

 

[gusu]

J-pipe and waste gate are where most people do the two lines to their boost controller.

This might also be boost creep from your intake and exhaust. Did you have your turbo ported?

 

[turboglenn]

might need to port the wastegate hole, my 16g spiked like mad untill i did, especially after freeing up the restrictions it was facing with all the little free upgrades

 

[gofer]

Read this for further info ---> http://www.dsmtuners.com/forums/newbie-forum/19752-turbo-boost-creep-creeping-t25-14b-16g-merged.html

You can verify its boost creep by sliding off the wga arm attached to the flapper on the hotside of the turbo and then go WOT. In theory you shouldn't be able to build ANY boost, if it does build boost what your seeing is your setups inability to effectively recirculate your exhaust gases around the turbine wheel to prevent it from spooling out of your control i.e. boost creep.

Fixes...

- Port the turbine housing ---> Turbo Housing Port How-To, http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/390564-how-port-turbo-exhaust-housing-video.html?highlight=port, http://www.dsmtuners.com/forums/articles-intake-exhaust/386665-how-port-polish-turbo-exhaust-housing.html?highlight=port.
- Install the stock downpipe/exhaust/catalytic converter
- Get bigger injectors and a way to tune that way you can run 20psi+ of boost​

 

[gsx4357]

i think this turbo is already ported and thats why i didnt do it when i got the turbo...i just cant remember...but lets say it is ported...what then?

 

[gofer]

i think this turbo is already ported and thats why i didnt do it when i got the turbo...i just cant remember...but lets say it is ported...what then?

I gave you a list of fixes, if the hotside is ported then go down the list.

Fixes...

- Port the turbine housing ---> Turbo Housing Port How-To, http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/390564-how-port-turbo-exhaust-housing-video.html?highlight=port, http://www.dsmtuners.com/forums/articles-intake-exhaust/386665-how-port-polish-turbo-exhaust-housing.html?highlight=port.
- Install the stock downpipe/exhaust/catalytic converter
- Get bigger injectors and a way to tune that way you can run 20psi+ of boost​

 

[gsx4357]

ok so i believe i fixed the problem...the problem was simple...the spring in the MBC was to strong and i needed a weaker spring...went to ace hardware and bought a few springs of a weaker tension and the first one got better but still boosted like around 18 psi...i waiting now for the car to cool down so i can put one just a little bit weaker and it should do the trick. ill let you guys know how it goes.

ok i fixed the problem...got a weaker spring and now its working fine...thnx for all the input and help...it was much appreciated