Boost is uncontrollable....help

[whiteflash]

So i just put on a ported 14b turbine housing and an o2 dump and now it's boosting around 20psi in third and a little past 16psi in second. fourth and fifth gear are 14psi solid where it should be. i didn't touch my mbc before i did the swap, but i'm gonna try and turn it down to see if that helps. Any suggestions?

 

[smx55]

Having the same problem, ported out the turbo same boost controller same settings.....the only thing new is the motor everything is the same. On the old motor I was able to hold 13 PSI with no problem, with this motor the boost creeps up to 15 PSI and starts to slowly climes from there. I'm lost myself.....did a boost leak test and change the MBC today same problem

 

[JayRolla]

Are you guys running 3" exhausts. Sounds like a boost creep issue due to the poor engineering of the mitsu exhaust housings. You need to research boost creep and have the turbo ported correcty around the wastegate flapper.

 

[smx55]

Are you guys running 3" exhausts. Sounds like a boost creep issue due to the poor engineering of the mitsu exhaust housings. You need to research boost creep and have the turbo ported correcty around the wastegate flapper.

Yes, I'm running a 3" exhaust & down pipe. The turbo was ported along with the wastegate flapper....unless it was not done correcty. I wasnt having this problem with the old motor.

 

[kenamond]

Yes, I'm running a 3" exhaust & down pipe. The turbo was ported along with the wastegate flapper....unless it was not done correcty. I wasnt having this problem with the old motor.

To check for creep, disconnect the WGA arm from the lever on the turbine housing and make sure the lever turns freely. Also, check that the WGA is functioning properly (I'm not sure what the actuation pressure is for the 14b WGA, but someone on here will know). You can test this during a boost leak test which will also test the vacuum lines for cracks/leaks. Finally, if all of that checks out okay, do a test pull to see what your boost does while the arm is still disconnected from the WG lever. There would be nothing holding the flapper closed, so the turbo shouldn't boost. It shouldn't boost past ~5psi. If it does, you have creep.

 

[smx55]

To check for creep, disconnect the WGA arm from the lever on the turbine housing and make sure the lever turns freely. Also, check that the WGA is functioning properly (I'm not sure what the actuation pressure is for the 14b WGA, but someone on here will know). You can test this during a boost leak test which will also test the vacuum lines for cracks/leaks. Finally, if all of that checks out okay, do a test pull to see what your boost does while the arm is still disconnected from the WG lever. There would be nothing holding the flapper closed, so the turbo shouldn't boost. It shouldn't boost past ~5psi. If it does, you have creep.

My turbo is not a 14B its a 16G, I'm trying to get the WGA off the flapper door buts its not on a c- clip. Cant tell what it is without taking off the turbo.....it fall to low to see even from under the car. I did a boost leak test. The only leak that was found was the nut on top the Blowoff valve, oh and it will hold about 13-14 PSI ....along as I dont go WOT or it will go up

 

[kenamond]

My turbo is not a 14B its a 16G, I'm trying to get the WGA off the flapper door buts its not on a c- clip. Cant tell what it is without taking off the turbo.....it fall to low to see even from under the car. I did a boost leak test. The only leak that was found was the nut on top the Blowoff valve, oh and it will hold about 13-14 PSI ....along as I dont go WOT or it will go up

But the OP has a 14b.

Maybe someone around here with a 16g can tell you if/how the arm can be disconnected.

 

[whiteflash]

it doesn' t make sense because it holds 14psi in 4th and 5th but not third and second, so wouldn't that mean the wastegate is operating correctly? And wouldn't the o2 dump almost eliminate creep? and it was only creeping alittle before i did the dump and ported turbine housing. So i'm going to try a boost leak test and see if that helps even though i'm almost positive thats not the solution.

*Full three inch exhaust, no cat.

 

[kenamond]

it doesn' t make sense because it holds 14psi in 4th and 5th but not third and second, so wouldn't that mean the wastegate is operating correctly? And wouldn't the o2 dump almost eliminate creep? and it was only creeping alittle before i did the dump and ported turbine housing. So i'm going to try a boost leak test and see if that helps even though i'm almost positive thats not the solution.

*Full three inch exhaust, no cat.

Where are you getting your boost source for the MBC?

 

[turbolover10]

And wouldn't the o2 dump almost eliminate creep? and it was only creeping alittle before i did the dump and ported turbine housing. So i'm going to try a boost leak test and see if that helps even though i'm almost positive thats not the solution.*Full three inch exhaust, no cat.

No, an external wastegate would help.

Its creep, did you pull the arm off like suggested?

I ported my e3 and with the 3" exhaust I was happy to keep it @18psi, with a decent port job.

 

[I8URV8AWD98]

hold up? You ported the wastegate flaper?? Did you install the new bigger flapper??

 

[turbolover10]

My turbo is not a 14B its a 16G, I'm trying to get the WGA off the flapper door buts its not on a c- clip. Cant tell what it is without taking off the turbo.....it fall to low to see even from under the car. I did a boost leak test. The only leak that was found was the nut on top the Blowoff valve, oh and it will hold about 13-14 PSI ....along as I dont go WOT or it will go up

Its easy, my original clip broke so I just had a paper clip in there
Just pull the clip out and off the arm comes.
I'm not sure what type of 16g you have but I would imagine their all similar... Heres a quick pic.

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Here's a pic of my wastegate passage, "that allows 18psi minimum..
Could have taken more out but my last one cracked and I have supporting mods.

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[turbolover10]

I was doing some searching and you guys that are having creep issues might find this interesting if you haven't read it already.
http://www.dsmtuners.com/forums/turbo-system-tech/267309-evo3-16g-boost-creep-solved.html

 

[whiteflash]

Where are you getting your boost source for the MBC?

j pipe.

but i was doing some pulls in fourth and it creeps in 4th too. so i take back my previous statement.

 

[turbolover10]

Yea I ment to add that you probably weren't high enough in the rpms to tell...
Did you pull the wg arm??

 

[whiteflash]

I was doing some searching and you guys that are having creep issues might find this interesting if you haven't read it already.
http://www.dsmtuners.com/forums/turbo-system-tech/267309-evo3-16g-boost-creep-solved.html

I would do that but he's charging 50 dollars....

 

[whiteflash]

Yea I ment to add that you probably weren't high enough in the rpms to tell...
Did you pull the wg arm??

ya, lever moves freely

 

[turbolover10]

Better than buying a new o2 housing, external and getting your flapper welded.

How much did you take out of the w/g passage when you ported, more than my pic?? Could you port it anymore without causing cracks in the future? If you have a pic of the port work put it up...

ya, lever moves freely

Did you drive it with it disconnected?

 

[whiteflash]

Better than buying a new o2 housing, external and getting your flapper welded.

How much did you take out of the w/g passage when you ported, more than my pic?? Could you port it anymore without causing cracks in the future? If you have a pic of the port work put it up...



Did you drive it with it disconnected?

My port job isn't quite as good as yours. I'm about to go drive it without the arm on. be back in 15min

 

[I8URV8AWD98]

like is said.. DID you port it to big? Why port it without installing the bigger flaper..

 

[turbolover10]

He's porting the wastegate passage, I don't recall him saying anything about porting the flapper but I could be wrong...

 

[whiteflash]

like is said.. DID you port it to big? Why port it without installing the bigger flaper..

definitely didn't port it too big.

 

[whiteflash]

He's porting the wastegate passage, I don't recall him saying anything about porting the flapper but I could be wrong...

I didn't port the flapper. but i just got back from test driving with the arm disconnected and it only boosted like 2 psi and sounded like a tractor.

 

[whiteflash]

i was just thinking, my unported 14b turbine housing and stock 02 housing creeping far less than my ported turbine housing with o2 dump......doesn't make sense to me

 

[kenamond]

i was just thinking, my unported 14b turbine housing and stock 02 housing creeping far less than my ported turbine housing with o2 dump......doesn't make sense to me

Are you sure that you're not seeing boost spikes in the lower gears? You could try brake-boosting in 2nd to see what the boost stabilizes at, but don't let it sit at 20psi.

Not sure why you'd have more creep after porting unless you did it in such a way that the flow to the WG is worse than before. Below is a picture of my FP B28 port job, but I still have the stock exhaust (anyone wanna give me $500 for a 3" Megan turboback exhaust?).

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I'd still check the WGA to see where the actuation pressure is and that it is functioning properly. If you pressurize the WGA to ~12psi, the arm should be fully extended, and you can check how much the lever/flapper is being rotated as a result. Maybe the flapper is opening even less now than before for some reason (clocked the housing a bit off? Arm is hitting the heat shield?).

Do you have any preturbo exhaust leaks?

I'm running out of ideas.