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Discussion Starter · #1 ·
Ok guys everyone that has been trying to help out thanks so much we have found that the problem with this has been happening to alot of people.....(after searching on ever evo forum known to man)

The Situation: boost creep cause from a free flowing system.

I have an entire exhaust system....Megan Racing mani, o2, downpipe, testpipe and straight pipe(no muffler)..ALSO AMS fmic , ams licp. ALL running on stock turbo.NO fuel mods except SAFC 1

Boost Controller: Turbosmart Eboost- 19psi set

Basically my system just like alot of you is free flowing trying to save alot of time i have called every performance shop in the world to try to get some help on this.. Here is what i got....

Extreme- said nothing except they need money to tell me anything. But they did say i should just turn the boost down. :tease:
Buschur Racing- guys were awesome to speak with....they say basically either port the wastegate or swap to an external wastegate, or get more backpressure with muffler or cat.
Megan Racing- they have not run into any problems with this yet but am glad i have brought it to there attention. Basically i have not enough backpressure , they recommend running a muffler , porting wastegate or going external wastegate.

Basically ive come to the conclusion that basically sucks, it looks like :

A: Fuel pump to quit from hitting fuel cut at around 5-7 k rpms
B: Muffler- at least to stay in specs as much as possible with the emissions.And hopefully create some extra backpressure.
C:After ive done this hopefully iwont need to but the last steps if this doesnt work port the wastegate area and if that doesnt work, custom external wastegate.

****Keep in mind this was also because it is winter(Dec./Maryland...20 to 40 degs)and that i have found from everyone that has helped me......the freezing cold air is also causeing some boost creep problems and is part of the problem.

Please post any info or help u may have for this topic for me and others.
SPECIAL Thanks to the following people on the forums:
WARRTALON
TURBOLARRY
thanks so much for the help guys and please input if u can on anything else we can find to help this out, there have been many a posts about this boost creep problem caused by this. I will keep informed on this forum of my progress.


Jey Morris :thumb:
Morris Racing
Turbosmart
www.team-trinity.com
Lancershop
 

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Actually, I would say to turn the boost UP. You should be running 21psi, not 19. 19 is LOWER than stock for the 05, and you can run as high as 22psi in this weather on 93oct. You don't need a fuel pump until you crank up the boost on race gas or meth, but it's a good mod to have with an S-AFC, because it then allows you to pull out more fuel, which will delay fuel cut in cold weather. FYI, I used an S-AFC as my only tuning mod for about a year and never hit fuel cut except for when I was in 6th gear with the boost turned up a little too high and tried to roll into full boost from low RPM. Too much load with the boost set to high, but never in the action gears or when racing. I even ran 24-25psi on race gas with the S-AFC on a full exhaust and never hit fuel cut. Since you have the mani/O2/FMIC, this probably exacerbates the problem. Those mods are all a waste at 19psi, but they are good mods down the road. I think you really should just get a basic mail-in flash for $199 from Dynoflash and then worry about fine-tuning your S-AFC on top of the flash after you get a wideband and complete your logging device. Seriously, a flash would set you up beautifully, because it eliminates fuel cut. I don't know if the boost creep would continue, but it would definitely provide you a much better tune in addition to eliminating fuel cut.

Oh, just to be clear, by boost creep, you mean that the boost is RISING as your RPMs increase, right? How high is it rising by 7500rpm in 3rd?
 

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Discussion Starter · #3 ·
yeah man it is rising .....on a hard pull say 4th gear gunnning it it will hold 19 psi til about 4500 or 5000 rpm then bam 20,21,22, it will go up tonight when it was about 25 30 deg outside i hit 25 to 26 psi by redline.

R u sure about turning the boost up? especially with a boost creep this high? Even tho i have the Eboost i have the overboost protection on at around 22.5 psi so it reverts after that.

R u sure it would be safe to do this?

Thanks C. man

Jey
 

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How is the boost going up if your EBC stops it at 22.5? I'm not saying it's safe to turn your boost up with a major boost creep problem, but I am saying that you should have it said at 21psi for daily driving on 93oct. Have you tried just installing a regular MBC to see if the same problem continues? I've heard of boost creep, but I've never heard of it rising 6-7psi like that...wow.
 

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IMO, stay away from the idea of adding back pressure.
The only way I know how to combat boost creep is porting. It's a lot of work, but it's really the only thing that works. Break out the die grinder and a Dremel. :|
Creep comes from the exhaust gas taking the path of least resistance;
Through the turbine = boost creep vs. through the wastegate hole = controlled boost.
This is for a DSM turbine housing, but it's the best thing I've seen on porting. One thing to look at if you go this route, is the wastegate flapper opening fully? Do our little spots behind the flapper need grinding too?
http://www.dsmtuners.com/forums/showthread.php?t=186525
This is the one from vfaq for more ideas;
http://www.vfaq.com/mods/porting-turbo.html
Thinking about picking up a spare turbine housing and O2 sensor housing to work on. When it's done swap'em in, you'll have less down time, and then sell what came off your car. If you port those you might make a little money.
 

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What are you using to measure boost?

If you weld the wastegate shut on a stock turbo it will not carry over 21 psi to redline, so I can't see boost rising as your RPM's go up. Get a good mechanical boost gauge installed, and a MBC... then report back to us :)

Keith
 

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Discussion Starter · #7 ·
Before i try that keith, did u see my list of current mods? now even with all of those i still shouldnt see boost creep?

Thanks so much guys for all ur help.

Jey
Team Trinity
 

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MOMOJeyEvlEvo said:
Before i try that keith, did u see my list of current mods? now even with all of those i still shouldnt see boost creep?

Thanks so much guys for all ur help.

Jey
Team Trinity
Up until this year I was Buschur Racing stage IV with HKS 272 cams, and AEM EMS for engine management. In addition I had switched to a tubular exhaust manifold and O2 housing along with a EVO 6.5 TME turbo, plus a Magnus motorsports sheet metal intake manifold. Never had any boost creep issues.

The stock turbo (or stock based turbo's like the 20G varient) are not able to supply enough air at high RPM to give boost above around 20 psi even on a stock motor... and the more modified the motor the less boost the turbo will be able to supply at high RPM.

To put it simply, the turbo is not big enough to keep up with the engine, so boost creep is impossible.

This is why I suspect your boost measurement rather than your actual boost level.

Keith
 

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Discussion Starter · #9 ·
keith, i have already disconnected the ebc and ran the car off just the wastegate, i know it is not the boost controller, i really am so confused as how i can boost creep and no one else does with these mods, ps the motor is stock as far as all internals nothing but the intake fmic, licp, and full exhaust, AFC and others.....

Do u have a muffler or cat on ur car?
I will hook up the stock boost controller tomorrow and see what happens. And btw when i ran the car off the waste gate it did the same creep just ran to hold at 12 psi then crept up with that........

Thanks man for your help, keep it coming lol.......next idea?
Jey
 

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Well, I finally got a hold of a 10.5 housing and I remembered this thread. When looking at how much the wastegate opens, I noticed it was a little blocked and the flapperdoor wasn't swinging as far as I liked. Before grinding it opened about this much;
 

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(I should have taken a before and after photo :eek: , but in the above I held it open trying to show that the flapper partially blocked some of the wastegate flow before grinding)
... but grind a little relief spot in the turbine housing edge...
 

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... the flapper is now completely at a 90* angle to the wastegate port and doesn't hang in the flow. Try something like this to see if it helps with your boost creep.
 

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There's also quite a bit of material that can be removed from the wastegate holes themselves. It's what I hit in yellow and the chamber is way bigger on the otherside right before it meets with the flapper door.
 

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