Over Boosting? Need some help guys
 

Started out with a manual boost controller that came on the car, pretty sure its a ebay brand and a Bleeder style. Threw that in the trash and started over.

Got a Halman boost controller. Taped the compressor housing on my 16g, ran that to the bottom port then the side port on the boost controller to the wastegate.

The problem that i am seeing with both boost controllers is that the boost will keep going up all the way to 30 pounds ( Max psi my gauge reads ). Its dependent on throttle, so if i hold it at half throttle or so it will hold 15 pounds then if i go to the floor it will just boost to 30 or what ever. It wont hold a certain boost, it will fluctuate with the throttle.


With that said i was curious of the wastegate spring, The previous owner did a bunch of stuff wrong and so i thought i would start there. Hooked a vacuum line to the waste gate port. Hooked a regulator on a air hose and slowly gave the waste gate some air to see when the arm would move. Started moving around that 10-12 pounds of air.


So then with my Halman boost controller, i left the side port that goes down to the waste gate port connected, took off the line that went to my compressor housing but left it attached to the boost controller side, put my air compressor onto that line to act as the boost source. I then spun the controller all the way out so i should go off the waste gate spring (10-12 pounds). I gave it air to see when the arm would move and i could not get the arm on the waste gate to move. After thinking for a while i noticed that on the side port of the boost controller there is a little hole on the port, like a vent to relieve pressure. Problem was that with it venting so much air i could not get the arm to open the flapper. So i went and got a standard barb fitting that went into the boost controller that didnt have a vent.

I threw this all together and no change, i drove the car and had the same results i cant hold a certain boost it goes every where. I would really appreciate some input. What makes me think is why i had problems with the halman boost controller i shouldnt need to be swapping the fittings on it? I must be over thinking it.

Thanks for reading

Re: Over Boosting? Need some help guys
 

The little vent is there to bleed off boost pressure when you close the throttle so the wastegate can shut, the barb needs that little hole in it for proper operation. Sounds to me like you might have a serious case of boost creep. Is the wastegate passage ported? Does it have the larger 34mm flapper or the standard (29ish)? What o2 housing is on the car? Did you use all brand new vacuum lines on the boost controller?

Re: Over Boosting? Need some help guys
 

Run the car with no boost controller. Just a line from boost source to wastegate. If it still goes too high, then try a different boost source, like intake manifold. If it still goes too high then you have a bad boost creep problem or the wastegate is broke.

Re: Over Boosting? Need some help guys
 

Ill start with looping the vacuum line from the compressor housing to the waste gate that was my next step. Previous owner had the boost source from the intake manifold but during my research i read it was better to draw the source from the compressor housing? If i find out that looping my lines controls the boost what does this mean? that i have a bad boost controller? or my wastegate spring is bad. When i put air to the wastage its self, it activated the arm around the 10-12 pounds.

Ill put that fitting back on, i figured it was there for a reason just thought i would give it a shot with a different fitting. Wastage passage is not ported, and it has a 29ish? flapper. I have not got into any of that stuff yet so I'm going to assume its all stock. And stock o2 on it for sure. It has all new vacuum lines and no boost leaks.

Re: Over Boosting? Need some help guys
 

I'm starting to think your MBC might be bad. If you're local, DB sells a cheap, effective, generic MBC that quite a few of us have run over the year. I've also had great luck with the basic Joe P.

Re: Over Boosting? Need some help guys
 

looping the lines from the compressor housing to the waste gate fitting didnt do anything. Boost still goes with how much throttle i give it. Dont really know what would be causing this? It cant be my new hallman boost controller its a simple ball and spring.

Re: Over Boosting? Need some help guys
 

Wastegate stuck? Or your tapped boost source isn't providing what it should...

Re: Over Boosting? Need some help guys
 

If it's looped from wastegate to comp housing it can't be the mbc. I'd check Watergate preload if it's adjustable, or see if it's stuck shut.

Re: Over Boosting? Need some help guys
 

To rule out boost creep, you could unhook the wastegate flapper so it's open all the time, and see what your max boost at redline is.

Re: Over Boosting? Need some help guys
 

When i tested the waste gate to see what size spring was in there. I hooked up my air compressor to the waste gate port, ever so slightly watched the gauge on the compressor as i slowly turned it up and at about 10-12 pounds the arm moved, then slowly retracted. I will be unhooking the waste gate arm to see if there is a possibility the flapper is stuck shut. But if i find out that it is not stuck shut and is moving correctly my next step would be go to the intake manifold for the boost source. Is that a good start? This is starting to really confuse me

Re: Over Boosting? Need some help guys
 

Yes, perhaps your tapped compressor housing job is no good. Try a different boost source.

Re: Over Boosting? Need some help guys
 

alright ill go to the intake manifold for the boost source and ill plug the compressor housing hole. Ill let you guys know how it goes!!

Re: Over Boosting? Need some help guys
 

There is more boost at the turbo than at the intake manifold, so going turbo can help lower the boost. But intake manifold is more consistent for changing conditions and better for holding higher boost. Sometimes a boost source right on the turbo does not work though. But its a 16G on a DSM aka guaranteed boost creep. Usually it just creeps to like 21psi though.

Re: Over Boosting? Need some help guys
 

well I wanted to hold 15 maybe 20 pounds. So if I could get it to hold around there I would be happy. Might just start saving for a external waste gate set up, just drive it like it is because I can not figure out why this is happen. My friends DSM with his 16g and he only boost like 12 and it holds perfect

Re: Over Boosting? Need some help guys
 

Did you try this yet? If it still creeping that means your not able to vent off enough exhaust fumes through the wastegate exit to keep the compressor from still building boost.

This would eliminate both the mbc as the source and the wastegate.

Re: Over Boosting? Need some help guys
 

You cannot figure out why? Have u tried the 2 tests that were mentioned?

Re: Over Boosting? Need some help guys
 

If I unhook the wastegate arm to the flapper it wud just be closed ? It wudnt stay open. I took the arm off to see if it was stuck. And it moves free but is this what I should do just take the arm off so it's open when I boost ?

Re: Over Boosting? Need some help guys
 

Yes. You unhook the WG flapper and force the flapper so its just open, that way you forced it to bypass as much air as it can all the time. So your boost should be as low as it physically can be. Then you see if its still over boosting. If it is, then you know the issue is the wastegate just physically cant do any better and is your limiting factor. if the over boosting goes away, then you know the wg itself is not the issue and for some reason its just not getting told to open because you just proved that if its open it was nt overboosting, which is then why you try another boost source because perhaps there is some unforseen issue with the spot you are using now.

Re: Over Boosting? Need some help guys
 

Thank you guys a lot I'll let you guys know what happens !

Re: Over Boosting? Need some help guys
 

so i removed the arm and took it for a drive, at about 4-5k i was seeing about 20 pounds of boost and at about 6/6.5 almost 30 pounds of boost. So if i am thinking right this means i found the problem, and that is that my waste gate is bad? So start shopping for a big 16g Waste gate actuator?

Re: Over Boosting? Need some help guys
 

30psi is a ton of boost creep, wow.
Did you try hooking the actuator directly to the intake manifold vacuum source?

Re: Over Boosting? Need some help guys
 

Edit: I missed this post:

Do this:

Re: Over Boosting? Need some help guys
 

Boost source will be going to the intake next. with that flapper open like i had it. Shouldnt i have not been able to boost at all?

Re: Over Boosting? Need some help guys
 

It should have been as low as you can physically go if you were sure the arm was removed and flapper stuck actuated to have the wastegate channel open. That is why halon was saying if you still were getting creep with the wastegate fully open changing the actuator will not help cure your problem. You will need to enlarge the wastegate so you can vent off more air.

The steps people want you to take are as follows:

1. Open wastegate fully check air flow by disconnecting rod/actuating flapper. Once you confirm you can flow enough air to avoid the boost raising above your target point then go to step 2. If you cannot flow enough air you know this is your problem.

2. Hook actuator back up to compressor source without mbc installed. The boost should build to the point in which the spring holding the wastegate flapper is overcome by the boost pressure. The wastegate will then open and start diverting exhaust gases away from the turbo. If this works correctly and only creeps to a stable amount like the 20-21 psi shane said then you know this is going to be your boost level unless you set the mbc higher. You can then go to step 4. If your still getting a problem after this you can check the following: actuator arm stuck/not working bad actuator or go on to step 3.

3. Hook actuator up to inlet source. If this fixes your problem then it was something with the source. Go on to step 4.

4. Install mbc. Set boost level. If you set it below the 20-21 psi (or whatever psi the wastegate actuator/flapper is allowing to flow) its likely going to creep back up to that anyway. If you set it above it should build to the desired level and hold. If your just spooling building boost as before then you know its your mbc.

Re: Over Boosting? Need some help guys
 

If I am reading this right and the arm was removed to allow the flapper to open all the way right away, then you have bad boost creep. The fix would be a larger flapper and porting or an external wastegate. Another option is to choke the exhaust or intake system so that the turbo has a hard time making boost, which obviously isn't the best option for power.

Being able to hold 12psi fine with a 16G on a DSM is actually weird and not how they normally act. And what his car is doing does not matter and is not going to fix what yours is doing.

Re: Over Boosting? Need some help guys
 

How a 16g could build 30psi with an open wategate flap blows my mind, unless either 1) your flap is welded shut and you don't know, or 2) you are running no exhaust and are giving it more air than any 16g in history. Most barely get over 30 with a basically forced shut flapper.

Re: Over Boosting? Need some help guys
 

Bad boost gauge?

Re: Over Boosting? Need some help guys
 

Yes you are right i removed the arm, and gave her throttle and at about 6k had about 25 pounds of boost. Im debating on going with a larger flapper, but would like to go with a external wastage set up. But don't really have the money for that. For a proper external waste gate would you go off the manifold or the o2 housing? And i would need to weld that flapper hole shut.

Re: Over Boosting? Need some help guys
 

Manifold at the collector or O2 housing.
I have an O2 housing built for ext. WG if you ready to buy.

Re: Over Boosting? Need some help guys
 

I think i would want to go with a ext. WG at the collector of the manifold not the o2 housing? Ive read that you would need to do porting every time you change your turbo if i went with a ext. WG off the o2 housing. And that people recommend going with a ext. WG off the manifold.

Re: Over Boosting? Need some help guys
 

^Where the fuck are you reading this shit you come up with?

Well it worked for me just fine, I put in 28psi springs and it was rock solid.

Re: Over Boosting? Need some help guys
 

^Where the fuck are you reading this shit you come up with?

Well it worked for me just fine, I put in 28psi springs and it was rock solid.

Re: Over Boosting? Need some help guys
 

Read it some where on tuners a while back


Im going to look at how that thing is hooked up. The previous owner installed it.

Doesn't make any sense to me either like at all. The flapper is not welded shut from what i know i can move it with ease. I do have a 3inch turbo back exhaust but it still doesn't make any sense to me. Im going to take it apart this weekend and look into getting some parts.

Re: Over Boosting? Need some help guys
 

If you go off the o2 housing, don't expect it to perfectly fix the boost creep, unless you make the hole in the turbo bigger and port it.

Re: Over Boosting? Need some help guys
 

whats a good manifold that's mitsu flanged and has a provision for a Ext. WG? All the ones I see on classifieds and on extreme psi are t3 flanged.

Re: Over Boosting? Need some help guys
 

There is none.

Re: Over Boosting? Need some help guys
 

Wouldnt the solution with the test he did be to port the hole behind the flapper until its close to the size of the flapper? probably a ebay or amazon 16g ive read you have to do this to eliminate the boost creep on them.

Re: Over Boosting? Need some help guys
 

If it's a Chinese 16g just get rid of the Damn thing, they are known garbage

Re: Over Boosting? Need some help guys
 

not an ebay piece of shit

http://www.dsmtuners.com/threads/evo...%C2%94.163103/

I could...... but i think imma take a different approach.


Attachment 15134


Imma run a 10cm t3 turbine hosing on my 16g. Then get a nice t3 manifold, with a provision for a external wastegate. Then get a flange for the o2 housing and weld an elbow on it and maybe do a v-band down pipe i have always wanted.

Re: Over Boosting? Need some help guys
 

you are way over thinking this for something so simple