Boost spike and lags hard when I shift fast.

[NOOB1GDUDE]

What's up guys more problems with the car now. Here it goes. When I step on the gas pedal it boost fine than when I shift fast the boost lags a lot like super lags. This is all happening from 2k to 4K.The spike problem is like this from 2k rpm to 4K it holds 15psi after 4K it spikes out of control like if the boost controller was turn up all the way. I'm thinking it's the wga because the mbc is turned down all the way down and its boostin 15psi and like I said it will spike super high.

 

[FIBA M - EC17PSE]

Your lagging could be a result of a dirty maf sensor or even a bad maf sensor in general, its common for cars to do this and have the same effect,

The others i can think off are, boost leak or spark plugs are arcing badly causing it to have a flat spot.

Those are my ideas to look at from personal experiance from various cars ive owned.

 

[mitsumike0]

I would take the vacuum line running from the MBC to the boost sourc(J pipe maybe) and connect it directly to the wga. This will tell you if the wga is bad or the MBC is bad. Also check for leaks as previously noted

 

[NOOB1GDUDE]

Check it for leaks. None. New lines. And ran it straight to the wga and got 11psi till about 4K them bam super high boost all the way to 20psi +. Maybe creep? Look at my mods list. The weird thing is it use to run ok. Y now?

 

[AdR]

It sounds like either your wastegate is bad or not fully opening causing blockage upon higher flow. Internal wastegates push upon a diafragm to move the rod and open the wastegate flapper at a certain boost pressure. If the flapper doesn't fully open you start creeping or if the turbo outflows the wastegate hole (which is doubtful on a 14b). Before identifying the wastegate, disconnect the wastegate warm and open the flapper by hand, should be extremely easy to pivot the arm and you should not experience any resistance until it hits metal both ways.

If you have an adjustable rod wastegate it might even be an issue of preload but that would rarely be the case unless you tampered with the unit.

 

[NOOB1GDUDE]

Oh solved the lag thing the line was to long from the mbc to where it splits. But that was before I did the wga straight to the j pipe. The thing is driving me crazy. So far it's like this. With mbc 15psi to 4K than boost gos crazy. J pipe to wga no mbc 11psi to 4K than bam boost like crazy. Will be messing with the wga when I get off of work today. The crazy thing is that it holds boost very well until you get to 4K and then it's like if I was to shoot nos in a video game(nfs). Well keep on guys anything info will help.

 

[NOOB1GDUDE]

Ok people I now know what it is. It's the Wga. I took it out and tested it. the problem that it's having is the wga is not fully extended under max load. If I move the flapper it goes past the point of where it is. This is all tested at 20psi. So my next question is dose the wga even extend to the point where the flapper open all the way or is the wga good and I'm wrong?

 

[FIBA M - EC17PSE]

Ok people I now know what it is. It's the Wga. I took it out and tested it. the problem that it's having is the wga is not fully extended under max load. If I move the flapper it goes past the point of where it is. This is all tested at 20psi. So my next question is dose the wga even extend to the point where the flapper open all the way or is the wga good and I'm wrong?

the flapper never opens all the way up, it moves no way near the full swing, if its opening around 10mm thats enough,

 

[NOOB1GDUDE]

So I tested it again and @ 20psi it opens to about 10mm but that's at 20 psi which my car can't do rite now. @ 10 psi it's about 5mm and anything below that it doesn't even open. So the wga is good? 10mm seem really small to me. It's not even half way to the full extended flapper. The fapper gose about an inch than it fully open.

 

[FIBA M - EC17PSE]

its only releasing the pressure its not a vacuum and you would be surprised how little it opens, @JusMX141 is your man for turbos and can help out more on that info

 

[EvolutionPlus]

14b with a 3" - 2.5" straight pipe, boost creep will be a problem without porting the housings. I used to get boost creep on my 16g with a straight 3" until I ported my housing and I still got at times. That is on a 8cm 32mm FP housing.

 

[NOOB1GDUDE]

I'm gonna port it tomorrow. The o2 housing and turbine housing. But only the the flapper side. Than maybe it'll stop the creep.

 

[FIBA M - EC17PSE]

I'm gonna port it tomorrow. The o2 housing and turbine housing. But only the the flapper side. Than maybe it'll stop the creep.

The flapper side is not what is needed to be ported, the inside of the turbine from the manifold is whats needed, the flapper side wont help at all.

 

[EvolutionPlus]

The flapper side is not what is needed to be ported, the inside of the turbine from the manifold is whats needed, the flapper side wont help at all.

Well of course the Flapper side has an effect on boost control. Think about it, it's job is to release exhaust pressure to control turbo speed if the hole is to small to maintain a constant speed (i.e boost pressure) then you will get boost creep. Yes the Inside of the Turbine is very important but also porting the Flapper hole will help. Hence why I got a FP Housing with the bigger 32mm Flapper.

 

[FIBA M - EC17PSE]

Well of course the Flapper side has an effect on boost control. Think about it, it's job is to release exhaust pressure to control turbo speed if the hole is to small to maintain a constant speed (i.e boost pressure) then you will get boost creep. Yes the Inside of the Turbine is very important but also porting the Flapper hole will help. Hence why I got a FP Housing with the bigger 32mm Flapper.

Dont you mean the 34mm flapper?? the hole is not the biggest issue here. the area it covers does help and making a direct route to exit the turbine is 95% of helping more then the wastegate hole itself, ive done all this work on my own with guidance from justin and i kept the stock evo 3 32mm flapper and as many others have has great success this way then the hole wont be an issue in size,

Make it transistion from shsrp to smooth to the o2 housing will help flow a bit but as i said the inside of the turbine housing is key here

 

[EvolutionPlus]

Dont you mean the 34mm flapper?? the hole is not the biggest issue here. the area it covers does help and making a direct route to exit the turbine is 95% of helping more then the wastegate hole itself, ive done all this work on my own with guidance from justin and i kept the stock evo 3 32mm flapper and as many others have has great success this way then the hole wont be an issue in size,

Make it transistion from shsrp to smooth to the o2 housing will help flow a bit but as i said the inside of the turbine housing is key here

I'm not saying its the whole solution but it is worth looking at as well is all I am saying. Yes the inside flow of the housing is number one. Flow makes power but it also leads to boost creep because of his exhaust setup the flow is too much for the stock exhaust housing to handle.

 

[FIBA M - EC17PSE]

I'm not saying its the whole solution but it is worth looking at as well is all I am saying. Yes the inside flow of the housing is number one. Flow makes power but it also leads to boost creep because of his exhaust setup the flow is too much for the stock exhaust housing to handle.

Its not about flow for power but flow to make the passage alot less restrictive to be removed easier and follow the path of least resistance, if you take a td05 unported and ported housing its alot different, so making the wastegate hole bigger dont help.

Keeping a 2.5" DP and keeping some restriction helps more.

 

[GST with PSI]

Sounds like a classic case of boost creep. Typically, a 5mm-10mm WG opening would be enough to control the turbine. However, on a car with a tiny little turbine housing and huge exhaust system, that no longer holds true.

Bottom line, you need to increase flow through the WG so an adequate amount of exhaust gas bypasses the turbine. There are multiple ways to do this. However, the best and least intrusive way is to use a WG actuator that will completely open the flapper door rather than just crack it 5 or 10 millimeters:

http://www.dsmtuners.com/threads/new-solution-to-16g-boost-creep.428843/

http://www.dsmtuners.com/threads/how-to-get-rid-of-boost-creep-on-14b-16g-mhi-turbos.380373/

Now, you can port the WG hole instead, but the addition of a millimeter or two to the WG hole will probably have little effect when the current WG actuator's travel is severely limited.

Additionally, you could add restriction in the exhaust system itself, but I shouldn't have to explain why this is a bad idea.

Adding a WG actuator that opens the flapper completely is the easiest and most effective solution. If the car still creeps after that, then pull the turbine housing off and port it if necessary.

Wanna test it? Pull the WG actuator off, and wire the flapper door open. I bet you never get to 20psi at any RPM...

 

[FIBA M - EC17PSE]

Sounds like a classic case of boost creep. Typically, a 5mm-10mm WG opening would be enough to control the turbine. However, on a car with a tiny little turbine housing and huge exhaust system, that no longer holds true.

Bottom line, you need to increase flow through the WG so an adequate amount of exhaust gas bypasses the turbine. There are multiple ways to do this. However, the best and least intrusive way is to use a WG actuator that will completely open the flapper door rather than just crack it 5 or 10 millimeters:

http://www.dsmtuners.com/threads/new-solution-to-16g-boost-creep.428843/

http://www.dsmtuners.com/threads/how-to-get-rid-of-boost-creep-on-14b-16g-mhi-turbos.380373/

Now, you can port the WG hole instead, but the addition of a millimeter or two to the WG hole will probably have little effect when the current WG actuator's travel is severely limited.

Additionally, you could add restriction in the exhaust system itself, but I shouldn't have to explain why this is a bad idea.

Adding a WG actuator that opens the flapper completely is the easiest and most effective solution. If the car still creeps after that, then pull the turbine housing off and port it if necessary.

Wanna test it? Pull the WG actuator off, and wire the flapper door open. I bet you never get to 20psi at any RPM...

Since he has a 3" DP and a 2.5" after thats the reason why he is creeping, the 3" DP is a killer for this,
Thats why his car is doing this,

 

[FIBA M - EC17PSE]

Since your car has 3" DP and a 2.5" DP your creating your own issues! why do you need a 3" DP? and more so why go down in size on the exhaust system after the DP???

My advice, redo the DP to 2.5" and your most likely fix a big portion of your issues straight away. having a huge DP is pointless unlesz your needing it for huge power a 2.5" is plenty for most and would do till 600hp ish, only then it may become a restriction

 

[GST with PSI]

My advice, redo the DP to 2.5" and your most likely fix a big portion of your issues straight away. having a huge DP is pointless unlesz your needing it for huge power a 2.5" is plenty for most and would do till 600hp ish, only then it may become a restriction

Why would you redo anything in exhaust system that doesn't relate to the WG itself? Add a WG actuator that increases flow past the turbine. Done. The exhaust/downpipe is not the problem, it's just exacerbating the root cause of the issue, which I stated above: Poor flow through the WG.

As I said, a quick test to ensure a WG actuator fix would work would be to wire the WG open and ensure the car doesn't creep. Not to mention, it takes 5 min to do. I'd rather know I can fix my problem before implementing a solution, rather than rebuild the exhaust system and hope that solves my problem.

There are plenty of people who have fixed creep issues on 14b's who are running turbo back 3" exhaust systems. It's not like this problem has already been solved 4,000 times or anything...

 

[FIBA M - EC17PSE]

Why would you redo anything in exhaust system that doesn't relate to the WG itself? Add a WG actuator that increases flow past the turbine. Done. The exhaust/downpipe is not the problem, it's just exacerbating the root cause of the issue, which I stated above: Poor flow through the WG.

As I said, a quick test to ensure a WG actuator fix would work would be to wire the WG open and ensure the car doesn't creep. Not to mention, it takes 5 min to do. I'd rather know I can fix my problem before implementing a solution, rather than rebuild the exhaust system and hope that solves my problem.

There are plenty of people who have fixed creep issues on 14b's who are running turbo back 3" exhaust systems. It's not like this problem has already been solved 4,000 times or anything...

Its not related to the wastegate in sense but it is related to the problems directly and its been proven it is by using such a huge DP in the first place, of all the folks running a 3" DP alot have complained about creep more then folks running a 2.5" DP, 3" flows too much and there for causes boost creep as its moving too fast, the restriction slows it down and keeps it from creeping as much, ive been through many threads way before i even started building my turbo and exhaust system and this is why im specifying these areas and problem areas to address,

We can all stick to the WG idea all day long but the real reason is the DP and how bad the internal WG exit path is, the hole and flapper and movement is part of a fix for it but why are we trying to fix an issue that we know is going to help towards it but not 100% fix it when the DP and porting is going to 100% fix it as proven from many many threads,

 

[Eddie Tsi]

do the test again and check for leaks on the actuator and the vacuum line to the actuator. Sound like boost is bleeding off.

 

[GST with PSI]

Its not related to the wastegate in sense but it is related to the problems directly and its been proven it is by using such a huge DP in the first place, of all the folks running a 3" DP alot have complained about creep more then folks running a 2.5" DP, 3" flows too much and there for causes boost creep as its moving too fast, the restriction slows it down and keeps it from creeping as much, ive been through many threads way before i even started building my turbo and exhaust system and this is why im specifying these areas and problem areas to address,

We can all stick to the WG idea all day long but the real reason is the DP and how bad the internal WG exit path is, the hole and flapper and movement is part of a fix for it but why are we trying to fix an issue that we know is going to help towards it but not 100% fix it when the DP and porting is going to 100% fix it as proven from many many threads,

I have no idea what you just said. Perhaps proper punctuation would allow you to get your point across more clearly.

There are a million ways to correct boost creep. I'm not arguing your recommendations may not correct the issue. However, the way I'm recommending to correct it is the least intrusive, and the OP can test the outcome of the fix prior to actually performing the fix. Now, that fix may or may not work. However, if it doesn't work, he's not out much time, money, or effort.

Now, he can pull the turbo apart, port the WG or increase the flapper size. He can also add a restriction to the exhaust system by installing a smaller downpipe (which is retarded if you ask me, but whatever). You telling me these things should be the first step? If so, I would strongly disagree.

 

[FIBA M - EC17PSE]

I have no idea what you just said. Perhaps proper punctuation would allow you to get your point across more clearly.

There are a million ways to correct boost creep. I'm not arguing your recommendations may not correct the issue. However, the way I'm recommending to correct it is the least intrusive, and the OP can test the outcome of the fix prior to actually performing the fix. Now, that fix may or may not work. However, if it doesn't work, he's not out much time, money, or effort.

Now, he can pull the turbo apart, port the WG or increase the flapper size. He can also add a restriction to the exhaust system by installing a smaller downpipe (which is retarded if you ask me, but whatever). You telling me these things should be the first step? If so, I would strongly disagree.

The way i have written it is fine, i could have spaced some stuff out more sure.

You way is less intrusive sure i agree on that, im just listing the most accurate way to fix it then to hal fix it and hope it works and then go from there,

Going down is not really that retarded man, going too big is but its from a logical point though! as its just a waste and remember he is 3" DP and 2.5" DP back! (According to his profile) now thats not how it should be so if you think thats perfectly fine and my answer is retarded then well go ahead and think that. I on the other hand know thats wrong