# Overboost



## stormtrooper15 (Nov 13, 2017)

Hey guys/gals, I recently installed a ported intake manifold on my '15 ltz rs and it pops up with the P0234 turbo overboost. I'm new to turbos but I feel pretty comfortable in their operations. So, I've got an elite trifecta tune, injen cai, forge motorsports recirculating bypass valve and their wastegate. It currently has the "stock" spring, whether it's yellow or green I can't recall the color. After installing a ported intake manifold and the pcv fix kit V2.1 I now have the overboost code and the large lack of power. There is also some turbo flutter going on. I contacted trifecta and after explaining the issue to them, also adding in that I preloaded the wastegate upon installation about 2yrs ago, they said to undo the preload. Did that and it ran worse. Also, I have made trifecta aware of any add ons tune related since day one and have never had any issues. I've been wrenching about 30yrs and am certain in my abilities. I've owned a mk4 VW fwiw lol. I contacted the person who ported the manifold, a chevy employee who does these on the side, asking if the problem has occurred to other purchasers. No response, not a good sign obviously. I'm about ready to put my stock manifold back on and call it a day. I should also mention that I've gone over my work several times looking for any visible signs of problems. I haven't found any, especially paying attention to the wastegate vacuum lines. I find it difficult/impossible to believe that the wastegate suddenly pooped out after 2yrs and only 5k miles. Yes, I don't drive it much. So, any suggestions/insight/epiphanies/advice is appreciated. I'm waiting to hear back from trifecta as I did a data log after the problem occurred. Thanks in advance. 


TLDR:

Trifecta elite tune 
Forge motorsports wastegate with their stock spring
Forge motorsports atmospheric bypass valve 
V2.1 pcv fix kit
** ported manifold causing overboost**

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## Thebigzeus (Dec 2, 2018)

The atmospheric bypass valve is sticking if you’re getting turbo flutter. Take it apart and grease it up.


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## stormtrooper15 (Nov 13, 2017)

Thebigzeus said:


> The atmospheric bypass valve is sticking if you’re getting turbo flutter. Take it apart and grease it up.


I appreciate the help. In my understanding of how the pieces/parts of how a turbo'd motor operates, the flutter is due to too much air being introduced. The air has nowhere to go so it goes backwards. The wastegate has under 5k miles and zero previous problems. It's all too coincidental that this happens immediately after installing the ported manifold. Trifecta, and info I've found online, suggests it's more than likely the wastegate itself or its actuator arm being bent. Both which I highly doubt as the zero problems I stated previously. Initially trifecta sent the updated tune, to include the manifold, they did so without a data log. I've done a log and sent it off to them. This was friday afternoon so I don't expect any response for awhile. I'm trying to narrow it down further myself as I'm not the type to sit back and wait for someone else to fix things for me. Chances are I expect trifecta to say that the tune is fine and updated appropriately. Thanks again 

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## Thebigzeus (Dec 2, 2018)

"In my understanding of how the pieces/parts of how a turbo'd motor operates, the flutter is due to too much air being introduced. The air has nowhere to go so it goes backwards." 

That would be incorrect, flutter is when the throttle body closes and the air has no where to go because your bypass or blow off valve isn't functioning, so it skips backwards over the turbine and makes a flutter sound.









5 “Facts” About Blow-off Valves (BOV) That Are Wrong • Turbosmart


The blow-off valve (BOV) or Bypass Valve (BPV) is what Turbosmart was built on. It was the first product we ever made. #KeepOnBuilding




www.turbosmart.com





"That fluttering noise that some turbocharged cars make when the throttle is suddenly closed, such as during gear changes, is the result of compressor surge.
It’s a fairly complex phenomenon which we explain in far more detail here. Basically, that flutter is the sound of a turbocharger trying to push air but failing due to a closed throttle, and it dramatically increases load on the bearings of the turbo."

My forge BPV stuck from the factory which made my turbo flutter and had to be cleaned and greased the day I got it. Just an FYI. Should also be done every oil change. I don't however think this is the main cause of your overboost code, but it is possible and something I would fix before moving too far forward.


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## stormtrooper15 (Nov 13, 2017)

Thebigzeus said:


> "In my understanding of how the pieces/parts of how a turbo'd motor operates, the flutter is due to too much air being introduced. The air has nowhere to go so it goes backwards."
> 
> That would be incorrect, flutter is when the throttle body closes and the air has no where to go because your bypass or blow off valve isn't functioning, so it skips backwards over the turbine and makes a flutter sound.
> 
> ...


Any suggestion on what grease to use? This is my first forced induction vehicle and haven't had yo deal with this stuff before. Once again, I appreciate the help.

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## stormtrooper15 (Nov 13, 2017)

The info I was going by









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## Thebigzeus (Dec 2, 2018)

stormtrooper15 said:


> Any suggestion on what grease to use? This is my first forced induction vehicle and haven't had yo deal with this stuff before. Once again, I appreciate the help.
> 
> Sent from my SM-G955U1 using Tapatalk


No worries, I will go out in the garage and grab a pic of that I used. I emailed Forge to ask what was best. And more isn't better, just a thin coat of it.


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## Thebigzeus (Dec 2, 2018)

stormtrooper15 said:


> The info I was going by
> 
> 
> 
> ...


Right, the wastegate on these is internal on the turbo and somewhat known to have issues. Yours may be sticking hence the overboost.


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## stormtrooper15 (Nov 13, 2017)

Thank you very much. Realizing that there's an internal wastegate on the turbo, how does greasing the bypass valve help? Not being a d!ck, I honestly don't know. I assumed that trifecta was referring to the forge motorsports wastegate being the problem and not the internal one in the turbo.

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## Thebigzeus (Dec 2, 2018)

Thebigzeus said:


> No worries, I will go out in the garage and grab a pic of that I used. I emailed Forge to ask what was best. And more isn't better, just a thin coat of it.


It's red, not the red tacky stuff though.


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## Thebigzeus (Dec 2, 2018)

stormtrooper15 said:


> Thank you very much. Realizing that there's an internal wastegate on the turbo, how does greasing the bypass valve help? Not being a d!ck, I honestly don't know.
> 
> Sent from my SM-G955U1 using Tapatalk


Gets rid of the flutter that shouldn't be occuring. Likely won't help with the overboost, but since it is a fault that shouldn't occur, it's where I would personally start.


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## stormtrooper15 (Nov 13, 2017)

That works, thank you 

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## Thebigzeus (Dec 2, 2018)

Keep us updated, I'm sure someone else will chime in too.


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## stormtrooper15 (Nov 13, 2017)

Thebigzeus said:


> Keep us updated, I'm sure someone else will chime in too.


Will do, it's unfortunate that too many posts are left without any update.

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## Noiitekk (Feb 28, 2017)

I was having an overboost problem because I had my adjustable wastegate actuator set to too much preload. I had it at 2.5 turns so I backed it off half a turn and it's been golden.

As others have said, these cars depend on recirculation of boost so by using an atmospheric it kinda doesn't run as it should. I picked the forge recirculating valve for that reason.


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## stormtrooper15 (Nov 13, 2017)

Noiitekk said:


> I was having an overboost problem because I had my adjustable wastegate actuator set to too much preload. I had it at 2.5 turns so I backed it off half a turn and it's been golden.
> 
> As others have said, these cars depend on recirculation of boost so by using an atmospheric it kinda doesn't run as it should. I picked the forge recirculating valve for that reason.


I just noticed that I said atmospheric , I'm an idiot. I have the recirculating bypass valve. Gonna correct my post. Thank you for catching that 

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## stormtrooper15 (Nov 13, 2017)

Mine is set at a half turn at the moment. I haven't driven it since I made the change from setting it back to "normal". Do you also have a ported intake manifold? I'm thinking that it's the cause of my problem.

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## Thebigzeus (Dec 2, 2018)

This is how much mine is preset in. Only way I can keep it closed at high rpms. I also have the atmospheric, it works fine but does create a rich condition when it blows off temporarily.


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## stormtrooper15 (Nov 13, 2017)

Any idea on how many turns it is? For the data log I did it required it to be driven around for awhile. I've already put it through it's paces and don't want to run any additional risk of blowing gaskets and seals. Kinda why I'm posting it and trying to get more information instead of sitting on my hands waiting for trifecta to get back to me. I don't like to sit and wait feeling helpless while someone else fixes things for me. Just not who I am. Do you also have a ported intake manifold? It got brought to my attention that I said I have an atmospheric bypass valve vs what I actually have, the recirculating bypass valve. None of my other mods caused any problems, and trifecta has updated my tune along the way with zero issues. Which is partially my reasoning that it has to be the manifold vs my wastegate. It's all happened literally 5 miles into testing it. 

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## Thebigzeus (Dec 2, 2018)

No, stock manifold here. 2-2.5 turns in sounds about right. Even though they say only 1/2 in. 🤷🏻‍♂️ Maybe it depends on the car.


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## stormtrooper15 (Nov 13, 2017)

Thebigzeus said:


> No, stock manifold here.


Ah, I don't expect to find someone running the same mods as me and who has dealt with this already. I don't think I have much of an option but to wait and hear from trifecta. I really do appreciate your help. 

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## JLL (Sep 12, 2017)

stormtrooper15 said:


> Any idea on how many turns it is?


I'm not sure for your specific wastgate actuator, but for the ZZP Actuator, preload is 3 half turns clockwise beyond the point that the wastgate is fully closed.


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## Blasirl (Mar 31, 2015)

I have both the Forge BPV and wastegate sitting in a box waiting to be installed. I looked again, but could not find some posts that explain why not to touch the stock BPV and I assumed that would apply to the Forge as well. I have not looked at them since buying them so I did not yet read the instructions, assuming there are some. Can either of you post some pictures of the disassembled unit and point out the locations to grease? 

I am also Trifecta tuned. I thought about porting the manifold and may do that to my spare just to try it, but from what I have heard, you take a hit in mileage and the power increase is at the top end. As this is my DD, I am still on the fence about that.


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## stormtrooper15 (Nov 13, 2017)

Blasirl said:


> I have both the Forge BPV and wastegate sitting in a box waiting to be installed. I looked again, but could not find some posts that explain why not to touch the stock BPV and I assumed that would apply to the Forge as well. I have not looked at them since buying them so I did not yet read the instructions, assuming there are some. Can either of you post some pictures of the disassembled unit and point out the locations to grease?
> 
> I am also Trifecta tuned. I thought about porting the manifold and may do that to my spare just to try it, but from what I have heard, you rake a hit in mileage and the power increase is at the top end. As this is my DD, I am still on the fence about that.


I'm not able to show the areas that need greased, I have no idea either. I'd assume it would be fairly obvious once it's apart. The mentioning of preloading I actually ran across on YouTube but can't recall what I was initially looking for. It's been about 2 years ago but it shouldn't be too difficult to find. My wastegate came from BNR as well and there aren't any instructions. As for the ported manifold I also have heard that the mpg takes a little bit of a loss but nothing too crazy. As well as the loss of some power in the lower rpms but a decent increase in the middle to top end that more than makes up for the bottom end. When I hear back from trifecta I will make sure to update this post for future reference. At this point if I had the opportunity to do it over again I wouldn't change the manifold. That is subject to change if it's an adjustment of the tune on their end. Especially since I've had zero issues in the 3 years that I've been tuned. Thanks for the help guys/gals, it's appreciated. 

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## Blasirl (Mar 31, 2015)

stormtrooper15 said:


> I'm not able to show the areas that need greased, I have no idea either. I'd assume it would be fairly obvious once it's apart. The mentioning of preloading I actually ran across on YouTube but can't recall what I was initially looking for. It's been about 2 years ago but it shouldn't be too difficult to find. My wastegate came from BNR as well and there aren't any instructions. As for the ported manifold I also have heard that the mpg takes a little bit of a loss but nothing too crazy. As well as the loss of some power in the lower rpms but a decent increase in the middle to top end that more than makes up for the bottom end. When I hear back from trifecta I will make sure to update this post for future reference. At this point if I had the opportunity to do it over again I wouldn't change the manifold. That is subject to change if it's an adjustment of the tune on their end. Especially since I've had zero issues in the 3 years that I've been tuned. Thanks for the help guys/gals, it's appreciated.
> 
> Sent from my SM-G955U1 using Tapatalk


Everything I have read that appeared reliable says to have the ported manifold added to the tune. So I would think that is primarily your issue. Fix all the other issues first though so Vince doesn't have to deflect...

Please do keep us updated.


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## stormtrooper15 (Nov 13, 2017)

Blasirl said:


> Everything I have read that appeared reliable says to have the ported manifold added to the tune. So I would think that is primarily your issue. Fix all the other issues first though so Vince doesn't have to deflect...
> 
> Please do keep us updated.


I did have the tune updated and made trifecta aware ahead of time. I must have left that important piece of info out of my post. I contacted them before installing the manifold and they updated my file then sent out the tune. After installing the manifold and the updated tune is when this all started. I have done a data log and sent it out to them. They didn't require a data log after updating the tune. It was supposed to be good to go. I've been with trifecta for 3 years and have updated them regularly after installing new pieces/parts that would require an update. I haven't had any problems with trifecta nor have I gone off the rails on them in any shape or form. I've only dealt with Steven or Michael before, all through the messaging portion of their website. I find it difficult to believe that it's the tune, I could be wrong though. Especially since I've reached out to the chevy employee who does the porting as a side project and he's ignored all my messages on FB messenger over the past few days. I've also not jumped down his throat or been disrespectful at all. Even when the manifold was shipped out a few days late. I've simply asked him if he's had anyone else run into this problem after installing one of his manifold and been ignored. I realize that things happen beyond our control, but after being told that if I have any issues to just him know and he'll send out a replacement one. Ignoring the request for assistance after the money has changed hands isn't helping my faith in him or his work. 

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## stormtrooper15 (Nov 13, 2017)

Blasirl said:


> Everything I have read that appeared reliable says to have the ported manifold added to the tune. So I would think that is primarily your issue. Fix all the other issues first though so Vince doesn't have to deflect...
> 
> Please do keep us updated.


I edited my post to show that I have had the tune updated each time it's been required in relation to the tune. Thanks for catching that for me. 

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## Blasirl (Mar 31, 2015)

stormtrooper15 said:


> I did have the tune updated and made trifecta aware ahead of time. I must have left that important piece of info out of my post. I contacted them before installing the manifold and they updated my file then sent out the tune. After installing the manifold and the updated tune is when this all started. I have done a data log and sent it out to them. They didn't require a data log after updating the tune. It was supposed to be good to go. I've been with trifecta for 3 years and have updated them regularly after installing new pieces/parts that would require an update. I haven't had any problems with trifecta nor have I gone off the rails on them in any shape or form. I've only dealt with Steven or Michael before, all through the messaging portion of their website. I find it difficult to believe that it's the tune, I could be wrong though. Especially since I've reached out to the chevy employee who does the porting as a side project and he's ignored all my messages on FB messenger over the past few days. I've also not jumped down his throat or been disrespectful at all. Even when the manifold was shipped out a few days late. I've simply asked him if he's had anyone else run into this problem after installing one of his manifold and been ignored. I realize that things happen beyond our control, but after being told that if I have any issues to just him know and he'll send out a replacement one. Ignoring the request for assistance after the money has changed hands isn't helping my faith in him or his work.
> 
> Sent from my SM-G955U1 using Tapatalk


For your own peace of mind, remove the manifold and look at the ports. The only thing different from stock is the thin plastic half walls are gone. I will try and locate a picture or two later.


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## Thebigzeus (Dec 2, 2018)

Blasirl said:


> For your own peace of mind, remove the manifold and look at the ports. The only thing different from stock is the thin plastic half walls are gone. I will try and locate a picture or two later.


Yeah, it really shouldn’t throw an overboost code or even require a tune update in my opinion.


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## stormtrooper15 (Nov 13, 2017)

Blasirl said:


> For your own peace of mind, remove the manifold and look at the ports. The only thing different from stock is the thin plastic half walls are gone. I will try and locate a picture or two later.


No need to look for pictures, I installed the manifold. It was ported by a Chevy employee.

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## stormtrooper15 (Nov 13, 2017)

Thebigzeus said:


> Yeah, it really shouldn’t throw an overboost code or even require a tune update in my opinion.


The overboost code could very well be from the manifold. The ecm/ecu is reading a higher air flow rate than normal. Approximately 40% of the manifold runners "wall" has been removed. After seeing other posts here/there relating to ported manifolds some are tuned and some aren't. It is possible that it's an improperly updated tune from trifecta, but I'm doubting that simply because of their length of time in the aftermarket tuning world. Still a possibility though. I'm contemplating turning the tune off and running the car around the block to see what happens. Hopefully narrowing it down between the tune or the manifold. My only concern is that I've already done more driving than I prefer, simply because of running a data log for trifecta. I'd like to keep my motor in one piece vs blowing out gaskets and seals due to the overboost condition.

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## Blasirl (Mar 31, 2015)

On the LUJ/LUV engine, indeed an adjustable length threaded rod is used between the WGA and the wastegate, but the factory attempts to prevent tampering by using some sort of locking compound on the threads. This isn't enough to stop a dedicated tinkerer, but we wholly recommend AGAINST modifying the length of this arm for the simple reason that it can cause the turbocharger to overspin which leads to either a failed turbocharger assembly, or a failed engine.

_LUJ/LUV WGA showing tamper-resistent compound on actuator arm adjustment_

Additionally, changing the WGA rod length will have no effect on the boost potential without corresponding tuning changes because the ECU will detect there's more boost than expected and simply respond by either commanding less BCS duty cycle, or closing the throttle.

This is an excerpt from this article:








Consistent Boost Levels on the 1.4T LUJ/LUV Engine


Control your Boost Turbocharged engines rely one of a few different methods of controlling the boost level. Most modern-day gasoline engines rely on a “wastegate”, while diesel engines generally rely on Variable Geometry Turbochargers (VGT). In both cases, boost pressure and airflow is the result...



www.trifectaperformance.com


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## Blasirl (Mar 31, 2015)

I thought this might also help explain whats going on:

This diagnostic trouble code (DTC) is a generic powertrain code. It is considered generic because it applies to all makes and models of vehicles (1996-newer), although specific repair steps may be slightly different depending on the model. Trouble code *P0234* indicates the powertrain control module (PCM) senses a dangerously high boost pressure from the engine's forced induction system. Levels of boost in excess of recommended levels can compromise the structural integrity of the engine. 

Normally, an engine relies on the vacuum produced by the downward movement of the piston to draw the air and fuel charge into the engine. A supercharger or turbocharger is an air compressor used to increase the air and fuel charge entering the engine. This is known as "forced induction" which allows a much smaller fuel-efficient engine to create the power normally available with a much larger engine. The mechanical apparatus used in forced induction is divided into three categories, positive displacement (roots style), centrifugal and turbo. The roots style and centrifugal chargers are belt driven while the turbo relies on pressure from the exhaust to operate. A roots or positive displacement supercharger is positioned on the top of the intake. A centrifugal looks much like a rotary air conditioning compressor and is located on the driver's side front of the engine. 

Turbochargers are located in line with the exhaust system. As boost pressure rises, the stress on the engine increases as well. Your engine has recommended boost pressure limits to preclude the possibility of engine component failure. Code P0234 is set when these limits are breached and should be corrected as soon as possible to prevent engine or transmission damage. Turbo chargers rely on exhaust pressure to spin the turbine blades fast enough to produce air pressure greater than atmospheric. However they have an inherent lag where the exhaust pressure is insufficient to spin the turbo fast enough to create pressure. Depending on the type of unit used, the turbo needs 1700 to 2500 engine rpm before it begins to "spool up." Turbos spin around 250,000 rpm in full boost. Boost pressure increases with engine rpm. 

_*To regulate the boost pressure and prevent overboost, a wastegate valve is installed. Most modern turbos have an internal wastegate and external actuator. There is a rod from the actuator to the wastegate on the turbo. Intake manifold air pressure passes to the top of the wastegate. As boost pressure increases it begins to exert force on the spring in the actuator that holds the wastegate valve closed. The higher the pressure rises, the more it overpowers the spring, resulting in the wastegate opening and directing exhaust gas away from the turbo blades and preventing further increase in boost. Regulation of the pressure applied to the wastegate regulates the boost levels at specific rpm. To accomplish this, the computer uses barometric or MAP sensors, engine and transmission temperature sensors, knock sensors and intake pressure sensors to determine the amount of wastegate opening necessary to deliver the best boost levels. To regulate boost levels, the computer uses either a solenoid, stepper motor or pulse modulator. By regulating the pressure to the wastegate actuator, varying degrees of boost are possible.*_ 
Read more at: P0234 Turbocharger/Supercharger Overboost Condition DTC


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## stormtrooper15 (Nov 13, 2017)

Thanks but I'm completely aware of the functions of each part. I have a forge motorsports wastegate so I wouldn't be messing with the stock actuator arm whatsoever. My trifecta tune is updated for the wastegate, bypass valve, cold air intake and the ported manifold. The overboost didn't occur until after the manifold and updated tune was done. I'm not sure if there's a miscommunication or misunderstanding here. I'm only asking if someone else has ran into the overboost problem after installing a ported manifold. I do appreciate the help though.

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## Blasirl (Mar 31, 2015)

I'm out


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## stormtrooper15 (Nov 13, 2017)

Blasirl said:


> I'm out


Simply because of me responding that the information you've given me I've already covered and posted as such. The link as to why not to adjust the factory wastegate actuator arm has nothing to do with the forge motorsports wastegate I'm running... Go grab your blanket and take a nap. I've not been disrespectful towards you in any way or form. Too many snowflakes in this world anymore.

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## Thebigzeus (Dec 2, 2018)

Well


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## stormtrooper15 (Nov 13, 2017)

Thebigzeus said:


> Well


It escalated quickly [emoji2369]

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## stormtrooper15 (Nov 13, 2017)

Blasirl said:


> I'm out


I need to apologize to you, publicly, since this is a public forum. I didn't delve deep enough into the links you provided. I've been frustrated the past few days with the car's performance and am alot shorter fused than normal. I truly am sorry Blasirl. After going deeper into the second link that you provided it seems that I may have found a possible solution. I plan to start by adjusting the wastegate actuator arm clockwise(in)two full turns. Depending upon how that works out I will either turn it clockwise another full turn(3 in total)or change the spring inside the wastegate. It seems that the overboost almost acts counterintuitively for how I understood the process. I was thinking that it caused too much pressure on the spring when in turn it actually needs more spring pressure. I will still keep the post updated for future reference. 

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## stormtrooper15 (Nov 13, 2017)

Thebigzeus said:


> Well


Due to my frustration and lack of delving deep enough into attached links.

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## Thebigzeus (Dec 2, 2018)

stormtrooper15 said:


> I need to apologize to you, publicly, since this is a public forum. I didn't delve deep enough into the links you provided. I've been frustrated the past few days with the car's performance and am alot shorter fused than normal. I truly am sorry Blasirl. After going deeper into the second link that you provided it seems that I may have found a possible solution. I plan to start by adjusting the wastegate actuator arm clockwise(in)two full turns. Depending upon how that works out I will either turn it clockwise another full turn(3 in total)or change the spring inside the wastegate. It seems that the overboost almost acts counterintuitively for how I understood the process. I was thinking that it caused too much pressure on the spring when in turn it actually needs more spring pressure. I will still keep the post updated for future reference.
> 
> Sent from my SM-G955U1 using Tapatalk


More spring pressure simply holds the gate shut at higher Rpms. That’s it. Mine was blowing open and I kept turning in 1/2 turn every drive until it either overboosted or stopped losing boost at high rpms.

Blasirl is always here to help, he’s good people and tends to give the info needed but require a bit of inference.


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## stormtrooper15 (Nov 13, 2017)

Thebigzeus said:


> More spring pressure simply holds the gate shut at higher Rpms. That’s it. Mine was blowing open and I kept turning in 1/2 turn every drive until it either overboosted or stopped losing boost at high rpms.
> 
> Blasirl is always here to help, he’s good people and tends to give the info needed but require a bit of inference.


I need to go and dig out my wastegate box, I'm thinking it has the yellow spring in it and the green one inside the wastegate. If that is indeed the case then from what I'm reading on trifecta's own it website says to use the yellow spring. I could be wrong, it's clearly been one of those days already. 

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## stormtrooper15 (Nov 13, 2017)

Ok, my bypass valve(recirculating)does have the green spring inside. I will be continuing as planned. The wastegate arm will get turned in an additional 2 full turns, setting it at 2.5 clockwise turns. Depending on how it acts I will probably be putting the yellow spring in the bypass. What color spring is anyone else using?

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## stormtrooper15 (Nov 13, 2017)

Update 

I heard from trifecta a little bit about and they suggested that I try the yellow spring in the bypass valve. Tomorrow I will adjust the wastegate actuator arm first and then change the spring if necessary. 

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## stormtrooper15 (Nov 13, 2017)

New update:

Still waiting to hear from trifecta, typically that means that the tune is fine, going by a few previous problems that have popped up here and there over the past 3 years. I upgraded to the yellow spring, stiffer, and no real noticeable difference. Decided to remove the forge wastegate and put the OEM wastegate back on. Issue resolved [emoji122] upon a quick look over the forge I discovered that the vacuum port was a little loose. How it happened I don't know. I was a bit surprised not to see any thread lock or tape on it. Granted it's very small threads and only 3 of them. It did have an O ring at least. I snugged the port back down and reinstalled the forge. I will be taking it out tomorrow to see how it goes. [emoji1696]

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## Blasirl (Mar 31, 2015)

stormtrooper15 said:


> New update:
> 
> Still waiting to hear from trifecta, typically that means that the tune is fine, going by a few previous problems that have popped up here and there over the past 3 years. I upgraded to the yellow spring, stiffer, and no real noticeable difference. Decided to remove the forge wastegate and put the OEM wastegate back on. Issue resolved [emoji122] upon a quick look over the forge I discovered that the vacuum port was a little loose. How it happened I don't know. I was a bit surprised not to see any thread lock or tape on it. Granted it's very small threads and only 3 of them. It did have an O ring at least. I snugged the port back down and reinstalled the forge. I will be taking it out tomorrow to see how it goes. [emoji1696]
> 
> Sent from my SM-G955U1 using Tapatalk


Use a bit of teflon tape on the threads.


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## stormtrooper15 (Nov 13, 2017)

I've already used a little bit of a silicone based sealant, very minor amount. It just elapsed the 24-72 hour cure time tonight. I'd contacted Forge, primarily to see if it was supposed to be loctited or teflon taped. I heard back from them today and was told to loctite it. I didn't ask if it was supposed to have been done via the factory during the production process. It wasn't as pertinent as it didn't really matter one way or another. I also switched back over to the green(OEM equivalent)spring in the bypass valve. Trifecta has requested a new data log since the previous log showed zero problems. I do believe that after I pick up some loctite tomorrow and use it on the vacuum port threads that the overboost will be officially fixed.[emoji1696]I'm surprised that this problem didn't come to light sooner, whether it wasn't enough of a vacuum leak to make much difference and the ECM corrected/compensated/adjusted the fuel to air ratio. Maybe the increased airflow from the manifold was enough to "trigger" the code. As odd as the timing of the code appearing just after the manifold installation it could very well just be a coincidence, I just don't believe in coincidences but I've definitely been wrong before. As noted when I was an a$$ to Blasirl earlier in the thread. I do appreciate him still checking in and posting suggestions on here. So, after the trip to get loctite, prescriptions, groceries etc. tomorrow I'll report back on the progress. 

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## stormtrooper15 (Nov 13, 2017)

Update 

Car ran great yesterday, I picked up some blue(medium strength)loctite that will stop the vacuum port from loosening up due to vibration and what not. It is removable with tools, so sturdy but not overboard. Will be doing another data log in the near future and preloading the wastegate actuator arm afterwards. It appears that the overboost issue is now resolved. Hopefully this will help someone else down the road. I'm sure that I've probably over explained the steps and results but I try to be thorough for future readers. 

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## Thebigzeus (Dec 2, 2018)

I have the bnr one, I think it’s just a rebranded forge. Could you post a pic of the screw in question?


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## stormtrooper15 (Nov 13, 2017)

Thebigzeus said:


> I have the bnr one, I think it’s just a rebranded forge. Could you post a pic of the screw in question?


It's actually the vacuum port and it's threaded so it screws into the body of the wastegate. I'll get a pic for you, it'll be from online though as I just loctited it earlier today. The BNR is very similar, also a forge as you mentioned.

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## stormtrooper15 (Nov 13, 2017)

It's circled in blue
















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## Thebigzeus (Dec 2, 2018)

Thanks! didn’t realize that threaded in. I’ll check mine soon.


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## stormtrooper15 (Nov 13, 2017)

Thebigzeus said:


> Thanks! didn’t realize that threaded in. I’ll check mine soon.


Welcome. I had no idea either, when I got mine it already had the vacuum hose attached and clamped down on it. 

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## stormtrooper15 (Nov 13, 2017)

After loctiting the vacuum port I did a decent test run and the car ran great. I sent out a new data log and there wasn't any changes needed. Now, a few days later the overboost code resurfaced. Went over all of my connections again, no issues there, vacuum port was still tight. Readjusted the wastegate actuator arm(stock position)and cleared the code. Car did just fine. However... I'm definitely not fond of the low end torque loss. The mid to high range is great but I can't accommodate myself to the low end loss. I've read numerous posts/topics related to the torque loss and gain that coincides with the ported manifold and some people don't notice any changes and some do. I was aware it was going to be a loss at the low end and had 50/50 thoughts on even installing one. I can say that I'm glad I did and won't suggest that anyone swap over to the ported version. Just my opinion and however anyone else views the ported version is totally fine too. I did switch back to the OEM manifold and am glad to not see the check engine light on light it has been since day 1. 



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## Gstout8604 (Aug 16, 2021)

Are you still running the pcv fix in the stock manifold?


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## Blasirl (Mar 31, 2015)

Gstout8604 said:


> Are you still running the pcv fix in the stock manifold?


Welcome Aboard!

Since you did not specify who you are asking, I'll answer...

I am and have not had any issues with it at all. I was an early adopter as well.

Don't forget to introduce yourself and your Cruze here.


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