Help Me Eliminate My Boost Spike/Creep

[Cgillies86]

Ok, I just bought this dsm; and it has massive boost creep. I don't know much about hese cars so I need help with eliminating the boost creep. If i floor the car the boost goes to 8 psi. Then at 4k it shoots to 15psi, at 5k the boost reaches 22 psi, and at 6k it skyrockets 30 psi. I pretty much stopped flooring the car because it boosts so high. I am not really sure what is causing the boost spike so any help would be appreaciated.

My Cars Mods:
Full 3 inch Exhaust Downpipe and back, Test Pipe, Hybrid Connection O2 Housing 2.5 inch, 2g Exhaust manifold, 14b Turbo, Dejon Tool 2.5 upper and 2.5 lower intercooler pipes, 3 inch air intake pipe, 7 inch K&N air filter, SBR boost controller, MAFT, GM MAF Blow-Thru, Walbro 255 fp, Aeromotive FPR, 450s, S-AFC II, pocket logger, EGR block-off and All other Emissions

Temperature was 30 degrees F.

Let me know if you have any ideas on how to reduce this boost creep.

 

[Cgillies86]

That sucks. Sorry to hear it, you ported the wastegate hole to didn't you??
I was told by an experienced friend of mine not to port the turbo inlet, JUST the path to the wastegate, as porting the whole thing decreases spool up time, and makes more room to allow the exhaust gases to enter the turbine wheel which is what we don't want. Are you running a stock(but ported) o2 housing? Sounds like your's and mine next best hope is an external gate... I have a cheap tubular manifold from punishmentracing.com that has a dump tube on it, and hope to be able to cut off the dump tube an inch or less from the flange and weld an external gate flange to it....

I have read some good info on messing with the actuator arm, look for pikens (his username on tuners) "easy cure for boost creep" or something to that matter. The guy never offered up and dimensions or anything on how to make the piece, but it simply raises the actuators arm (at the flapper area) a little higher making it possible for the wastegate to open further.

ALSO: I have heard that on some wastegates you can simply screw the wastegate arm, in or out to raise or lower boost; anyone know if this is true with the evoIII 16g?

Yea, I did port my wastegate hole bigger, its actually got 50% more area than stock. I have the hybrid connection Tubular O2 housing which is similar to a ported EVO O2. I am not sure if the EvoIII has an adjustable arm, but i wish the 14b had one. Well, atleast i know if i extend my actuator arm it will definetly fix it. I want to just verify that my boost controller is connected correctly b/c i have never checked. Here is a diagram of how i have my vacuum lines set up. My boost controller has the bleeder hole on the wastegate actuator side, and boost controller is screwed all the way out. Is that correct?

 

[oldman]

Even after all that porting I did, my turbo still boosts to 30 psi. But now with the turbine housing ported, it goes there insanely fast, almost instant. THe good news is, when I remove the wastegate arm from the flapper door, i dont make any boost until 5k and make less than .8 bars at the rev limiter. Before the porting, it would boost 30 psi even with the actuator arm off. I am wondering if I should just make my actuator arm longer. Let me know with any ideas.

Thanks

Damn, it's a good thing you did the arm off test before or else all this would have seem like such a waste of time. This is what I would do next,

1. Do the pressure test to the nipple on the actuator with the arm attached and make sure the actuator is opening the door all the way. If it doesn't, you know what to do. If it does, it can only means that pressure is not is not reaching the actuator. Go to 2.

2. Bypass the mbc and go for a test run. If still the same, go to 3.

3. Perform a REAL boost leak test, particularly the vacuum hoses to the mbc and to the actuator.

Post back.

 

[oldman]

I dont think I have much of a boost leak since about 2-3 weeks ago I installed a FMIC with new piping, and brand new couplers. I do not have my pipes beaded as of yet, but I've checked all the clamps and couplers (tightened all the couplers down more as well.

Just one last thing rowlex, when I did my front mount kit install I had similar problems. I didn't think I had any leaks because they were all tbolt clamps and I had tighten them 3 times. All my pipings were beaded. When I finally hooked up a compressor, I found eight leaks.

 

[Cgillies86]

Damn, it's a good thing you did the arm off test before or else all this would have seem like such a waste of time. This is what I would do next,

1. Do the pressure test to the nipple on the actuator with the arm attached and make sure the actuator is opening the door all the way. If it doesn't, you know what to do. If it does, it can only means that pressure is not is not reaching the actuator. Go to 2.

2. Bypass the mbc and go for a test run. If still the same, go to 3.

3. Perform a REAL boost leak test, particularly the vacuum hoses to the mbc and to the actuator.

Post back.

I was pretty discouraged about my porting not fixign it completly, especially since i cut my fingers pretty bad . But atleast I know the turbo flows even better now. . How exaclty do you do a boost leak test?

 

[rowlex]

I was pretty discouraged about my porting not fixign it completly, especially since i cut my fingers pretty bad . But atleast I know the turbo flows even better now. . How exaclty do you do a boost leak test?

To clear up some things JIC.

When oldman said to bypass the MBC, Hook a vacuum tube straight from the 14b J-pipe nipple (or the Boost source between the BOV and manifold) straight up to the nipple on your wastegate.

to make a boost leak tester check vfaq. But here is a simple run-down. get some radiator hose the size of your 14b inlet, get some PCV or similar material the same size to clamp the radiator hose to, put a cap on this PCV on one end only, make sure it seals. Drill a hole in the cap, place either a fitting to hook your compressor to and seal it, or if you dont have an air compressor, use a (sorry brain fart cant remember what its called) the thing you would hook a bicycle pump up to to pump up a tire. If you use a compressor, make sure it's got a regulator on it and turn the regulator down to 15-20 psi.

 

[rowlex]

Just one last thing rowlex, when I did my front mount kit install I had similar problems. I didn't think I had any leaks because they were all tbolt clamps and I had tighten them 3 times. All my pipings were beaded. When I finally hooked up a compressor, I found eight leaks.

Thats discouraging

I'll do a leak test soon then...

 

[oldman]

I was pretty discouraged about my porting not fixign it completly, especially since i cut my fingers pretty bad . But atleast I know the turbo flows even better now. . How exaclty do you do a boost leak test?

Yea I was a little disappointed as well but like I said before, problems can over lap each other. When you solve one, you reveal others. Just be patient and take it one at a time. Please do #1 & 2 as well. Remember when you mentioned the arm move about 1/2 inch when you applied pressure to it but wasn't sure if it was enough to open the door? Find out, it could be as easy as a bad actuator.

http://www.vfaq.com/mods/ICtester.html

 

[Cgillies86]

I tested out a few things on my car, and I found out my boost controller is bad. When i removed it from the system, my car held the boost at just above .6 bars then slowly crept to 1.2 bars. So, I guess if I get a new boost controller set it at or above 1.2 bars, I should not be creeping anymore. More problems have become apparent, I have some sputtering at 6500. Some times it refuses to rev past 6500 just holds that rpm. But atleast there is some positive.

 

[oldman]

I tested out a few things on my car, and I found out my boost controller is bad. When i removed it from the system, my car held the boost at just above .6 bars then slowly crept to 1.2 bars. So, I guess if I get a new boost controller set it at or above 1.2 bars, I should not be creeping anymore. More problems have become apparent, I have some sputtering at 6500. Some times it refuses to rev past 6500 just holds that rpm. But atleast there is some positive.

That is positive news. After you replace the mbc make sure you follow through with that leak test. If the sputtering continues after you fix all the leaks and able to hold 20psi during the pressure test, I would look toward ignition.

 

[rowlex]

I tested out a few things on my car, and I found out my boost controller is bad. When i removed it from the system, my car held the boost at just above .6 bars then slowly crept to 1.2 bars. So, I guess if I get a new boost controller set it at or above 1.2 bars, I should not be creeping anymore. More problems have become apparent, I have some sputtering at 6500. Some times it refuses to rev past 6500 just holds that rpm. But atleast there is some positive.

Nice! The sputtering is probably a boost leak. mine seems to be
I changed the plugs and wires, and still have a severe problem around 15PSI car just falls on its face. I had an experienced tuner helping me fix my car yesterday and we think its a pretty big boost leak. so def. check that

 

[Cgillies86]

It Works! Its set at 1.2 bars and it holds steady until redline. I hit fuel cut tho sometimes. My clutch slips like crazy now in 3rd gear or higher, but in 1st and 2nd it is alright. It is completly untuned and feels fast as heck. I am going to get my pocket logger back from my friend so I can begin to tune my car.

 

[oldman]

It Works! Its set at 1.2 bars and it holds steady until redline. I hit fuel cut tho sometimes. My clutch slips like crazy now in 3rd gear or higher, but in 1st and 2nd it is alright. It is completly untuned and feels fast as heck. I am going to get my pocket logger back from my friend so I can begin to tune my car.

 

[rowlex]

hey figured id keep all this to one thread.

I havent tested it too much but it seems i can now hold 1.3xx bar to redline with no nasty stuttering or anything. All i need to do is not be so lazy and plug in my laptop to tune it because I get some nasty knock at full boost around 5K rpm.. I also need to figure out how to plug the leak at my J-pipe. RTV? Lol... It's not a very huge leak but it's there.

 

[rowlex]

just a small update on my boost creep solution... this should do it

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inside, the pipe is welded inside the collector and outside. I think I will make two support bars for it.

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[oldman]

Very nice Rolex, looks like a lot of work. Are you re-routing or dumping? The only thing left to worry about is engine bay temperature, I would at least heat wrap the battery and make sure the intake get a good amount of fresh cool air. Good job.

 

[rowlex]

Very nice Rolex, looks like a lot of work. Are you re-routing or dumping? The only thing left to worry about is engine bay temperature, I would at least heat wrap the battery and make sure the intake get a good amount of fresh cool air. Good job.

I think I will have it dumped for short term then when i can afford get it re routed into the downpipe. Engine bay temps are already a problem, My car cannot cool itself, on hot days I overheat. I removed the driver side fan and replaced it with a slim fan on the front but it cant move enough air (still have my a/c core) It might have to go I think I am going to try to get some heat sheild material and seperate this stuff from the radiator. As well as try to pipe some cool air iinto the area.

my filter has a cold air box around it

 

[oldman]

I think I will have it dumped for short term then when i can afford get it re routed into the downpipe. Engine bay temps are already a problem, My car cannot cool itself, on hot days I overheat. I removed the driver side fan and replaced it with a slim fan on the front but it cant move enough air (still have my a/c core) It might have to go I think I am going to try to get some heat sheild material and seperate this stuff from the radiator. As well as try to pipe some cool air iinto the area.

my filter has a cold air box around it

Just like everything else you do, you win some and lose some. Here are some ideas which may help.

1. Water wetter.
2. Removing the AC core. (I'm trying to keep mine as well).
3. Aluminum radiator.
4. Exhaust wrap or ceramic coating.
5. Fab heat shield.

Did it at least completely solve your boost creep? BTW, sorry I spelled your user name wrong.

 

[rowlex]

Just like everything else you do, you win some and lose some. Here are some ideas which may help.

1. Water wetter.
2. Removing the AC core. (I'm trying to keep mine as well).
3. Aluminum radiator.
4. Exhaust wrap or ceramic coating.
5. Fab heat shield.

Did it at least completely solve your boost creep? BTW, sorry I spelled your user name wrong.

no problem, my name is scott I haven't tested it on the car yet as I didn't have time to install it, just test fit. I also want to port the entire inlet of the turbo. It should definently solve the creep. A buddy of mine is controlling a 50 trim with his welded onto just the #1 runner, so with this being off the collector should solve completly.

I am going to try the water wetter and fabing a heat sheild first
I also have a huge front mount so I will be fabbing up something with some tin to block the sides of the area between the radiator and FMIC (as i think air escapes from the sides) my main overheating issue is at speeds from about 7 mph to 35-40. With this setup I MIGHT be able to put my stock a/c fan back on to.

 

[Zexell]

It Works! Its set at 1.2 bars and it holds steady until redline. I hit fuel cut tho sometimes. My clutch slips like crazy now in 3rd gear or higher, but in 1st and 2nd it is alright. It is completly untuned and feels fast as heck. I am going to get my pocket logger back from my friend so I can begin to tune my car.

I would think that hitting fuel cut is a big problem. Im in the same boat as you. I have creep but if I set it so that I dont get creep, i get fuel cut.

Fuel cut causes detonation doesnt it?

 

[rowlex]

I would think that hitting fuel cut is a big problem. Im in the same boat as you. I have creep but if I set it so that I dont get creep, i get fuel cut.

Fuel cut causes detonation doesnt it?

I have never experienced fuel cut(first mod was dsmlink/walbro 255/650cc injectors/afpr), but I thought it was an induced rev limiter?