Hey all.. i just installed a hard upper pipe with a 1g bov.. cleaned outside and inside the intercooler... and reinstalled everything. All of the clamps on everything were loose, i tightened all of those... runnin a big 16g turbo...

before i did anything i know i had some major boost leakage... before when i would adjust the boost controller(obx manual) nothing... i mean nothing would happen.. it all stayed the same... 14lbs... it would only go to about 9lbs and then slowly climb to 14 at about 5500 revs... it was like the turbo was screamin just to hit it...

now, i can't keep it under 15 lbs.. i have made the plug so loose on the manual boost controller i can and did pull it out, it made a difference, but still was hitten 16lbs at about 80-90% throttle at 5000+ revs.. (i have stock fuel system.. ) so i immediatly let off.. I don't know why even with the boost controller ALL the way down with the plug pulled, it is still boostin like crazy!!

ANY HELP, INPUT, SUGGESTIONS ARE ALL APPRECIATED..THANKS IN ADVANCE

Are you sure you have that mbc hooked up right? Do you even have a boost guage?

Yeah i was wondering that , yu may need to check the system out and make sure its hooked up correctlly.

Yes... lol.. Please guys, i know that you deal with some newbies on here but c'mon
how would i be telling you what the psi's are goin to???

I believe it is all hooked up right... When i bought the car it had a greddy profec ebc on there, and i just put this one right in its place...

Now, i am new to turbo diagnostics coming from a supercharded world, so please feel free to give me a verbal diagram to follow that i can check first thing in the morning.. Thanks guys :thumbsup:

Have yu checked yur wastegate's operation and the boosts ABV? id check those things , seems yur turbo is overspooling possibly.

You might have the boost controller backwards.

okay.. i checked the boost controller that was not on backwards....
I disconnected it and ran just a line from the intake before the intercooler directly to the wastegate and went for a drive... hit 15lbs like nothin... does that mean my wastegate is bad or did i do something wrong? could it be a vacuum leak still?
Could it be a bad bov? is there a way to test?

On my system , i have intake vacuum line , a vacuum check valve and then the vacuum line goes Tee's to a vacuum solenoid and Vent solenoid and goes to the wastegate, im not sure if yur system is setup like this one but , possibly check the BOV operation and possibly operation of the wastegate, that its fully retracting and extending , depending the size of of the charge air piping , if will keep a higher charge side pressure if the inlet nozzle is factory size.

stock fuel system causing boost creep. did you enlarge your wastegate vent and flapper?

Yeah thats a good suggestion. Hmm it was the farthest thing frum my mind

No. What the heck ... i have never heard of this.. please explain...why.. how..

this is a very good write up

http://www.dsmtuners.com/forums/articles-t...ep-porting.html

basically, the wastegate flapper and the arm that controls the flapper inside of your turbine housing don't swing open far enough. To make matters worse the hole that the flapper opens or closes isn't large enough to let the proper amount of exhaust gasses to escape. When exhaust cant escape it flows into the turbine wheel and creates more boost.

In this case, when you go lean because you have a stock fuel system, the lean condition creates more heat. turbos love heat because it helps them spool and boost. More heat = more boost.

More heat + more boost + wastegate that can't allow enough exhaust gas to escape = boost creep and possible engine damage

Lean doesn't always mean a bad thing. someone that runs a 10:1 AFR will run richer than someone who runs a 11:1 AFR. both are safe, but the 11:1 AFR will burn hotter than the 10:1 and can cause the boost creep

16g's and actually all td05H turbos had this issue when trying to control low boost numbers at leaner than stock conditions. Thats why people always yell, WATCH OUT FOR BOOST CREEP when someone says they are turning up their boost on a stock car :thumbsup:

OR... you are adjusting the boost controller the wrong way. what kind is it?

no.. not bein adjusted the wrong way... its an obx... i have the plug completely out.. so basically a scan to watch my o2 temps would tell us alot then... so by porting the 02 housing this should take care of it?

Could it not also just be a wastegate issue? could it be that the wastegate is not opening far enough?

I will call my buddy and see if we can scan it tonight.. i will also take a hanger and tie the flap open and go for a cruze... see if that helps.. i guess that would solve the answer right there... if i go for a drive with the flap held all the way open and still get boost creep then i know i need to port the turbo correct?

by the way... thats an awsome right up.. thanks pwee

porting the o2 housing will only let exhaust flow more easily and is a good upgrade, but it's the wastegate hole in the turbine housing on the turbo that needs to be ported. and the edge where the flapper arm touches the housing needs to be taken back a little.

don't tie the flapper open, it won't boost at all and you might damage your actuator

if the plug in the boost controller is completely out it is letting air bleed off, what did it do when you had the plug screwed the whole way in? most of them work by screwing them tight lessens boost and loosening them increases boost.

already did the flapper deal.. still boosted past 15 lbs.. i let off then.. i believe that it needs to be ported and that to be my issue...
when the plug was all the way in it jumped to 18 lbs at about 3500 revs... and 50% throttle.. when i pull the plug all the way out it lessens it.. i can almost have the throttle all the way down at about 15 lbs till she gets to about 5g then she starts climbin again..
I am goin to my buddy's tonight to hook up his evoscan and check if and when i am gettin knock... i am not goin to be able to port it anytime soon i am afraid..
for the fun of it i will try tightening it again.. just to see what happens, but i am certain that it ran way more boost way faster when the plug was tight...

It seriously sounds liek a wastegate issue , at closed throttle the wastegate is spossed to bypass the exhaust air flow not to spool the turbo , also during the wastegate position is spossed to vary due to throttle position and manifold vacuum or lack there of . If the wastegate is not fully opening or bypassing enough air in partial to almost no throttle issues it will keep the turbo spooling even when it is not needed , making it maintain a higher boost pressure than desired.

Hey Kit, I was thinking the same thing till i tied the flapper open... which totally bypassed the wastegates funcion... what i noticed was no boost at all untill about 5g on the rpms then it shot to 10lbs then continued climbing till i let off at 16lbs...
Once it started spoolin i let off the throttle as to not overboost so i would say it was hitting 15+ with only 80 or so % of the gas goin... def. the porting issue i am thinking.. makes perfect sense and all my test have pointed to it being so...

Good to hear yu were able to make sum progress by the advice weve given , hope it gets sorted out. Reducing the turbine side flow should get yu where yu want to be and then have it at an adjustable stage where yu want to be , rather than wut it is now.