boost creep is killing me

[Ganja Man]

ok guys i have been trying to get rid of this boost creep forever now. heres my mods:

evo 3 16g ported with flapper
ported 1g exhaust mani
3 inch rnr o2 elim exhaust
hallman es mbc
intake
uicp
gm maf
maft
magnecore wires
datalogging software

after all this im still creeping very bad. holds 10 psi through 1st then at the end of second creeps to about 15. then when im in 3rd it will creep to 20+!!!!! ive heard that a external wastegate would help out but can i get that done to my current o2 housing since the downpipe and o2 housing are a whole? or any other suggestions? thanks

 

[David15151]

my 16g on a 2.5" exhaust creeped on a standard flapper.

 

[MrPikolo]

standard flapper on the 18g no cat and the evo3 o2 is suppose to mate perfectly with the 18g according to multiple stores ive spoken with...

ryan

What size exhaust you plan on running? I belive it's going to creep like a bastard.

GRNDSM pretty much already said the good ways to get rid of creep.

1. restrict your exhaust(add a cat or downgrade the piping. Not recommended for performance)

2. Upgrade to an extrenal wastgate.

I have a big 16g with standard flapper(mildly ported), custom made 2 1/2 O2 housing with an atmostpheric dump, and possibly one of the best 3" exhaust posssible with no cat. I have horrible boost creep in the upper rpms.

 

[flinguist]

Look for the posts by Tarantula on this thread. http://www.dsmtuners.com/forums/showthread.php?t=108843&page=2&pp=25
He eliminated boost creep with an EVO III 16G by doing a lot of port work.

 

[illusioneclipse]

I currently have an Evo III 16G turbo and it creeps like a bi***. I set the boost to 15lbs and in every gear it creeps to 20 lbs. Thats during the summer. Now it is fall/winter and the cold is making it creep to 25 lbs. I have recently taken everything apart (exhaust mani, turbo, O2 housing) and will be porting it all. I am still deciding though to get an external wastegate or go w/ my chances of porting everything and also upgrading the flapper.

 

[flinguist]

I currently have an Evo III 16G turbo and it creeps like a bi***. I set the boost to 15lbs and in every gear it creeps to 20 lbs. Thats during the summer. Now it is fall/winter and the cold is making it creep to 25 lbs. I have recently taken everything apart (exhaust mani, turbo, O2 housing) and will be porting it all. I am still deciding though to get an external wastegate or go w/ my chances of porting everything and also upgrading the flapper.

An external waste gate may not work either. You need to port the inlet side of the wastegate extensively, as well as the oulet side to eliminate creep. Some other things that will work are: 1) putting a restriction in the exhaust, like a cat. or resonator 2) doing a "PTE style" port job on the turbo exhaust housing, ie. remove the wall between the waste gate and turbine outlet.
I did the PTE style port job, and it worked, but it's supposed to hurt turbo efficiency.

 

[David15151]

um.. how do you say an external wastegate may not work? Assuming you install it correctly how would it not work?

 

[LandoAWD]

um.. how do you say an external wastegate may not work? Assuming you install it correctly how would it not work?

Some people just talk to be heard.

 

[flinguist]

I guess if it's big enough it should work, but it must be put on the manifold. See the last post on this thread http://www.dsmtuners.com/forums/showthread.php?t=141308&highlight=external+waste+gate

 

[ShapeGSX]

I only know of 3 ways to help boost creep.

1. porting the wastegate passage

2. larger flapper

Larger flappers just get in the way of the exhaust. With a larger flapper, the exhaust has a larger obstruction to have to flow around.

 

[Ganja Man]

ok guys heres what i think im going to do. im going to get the bullseye turbine housing and get an external wastegate on the exhaust manifold. my friend said i should also get the turbo clipped but will this actually help eliminate boost creep? thanks

 

[David15151]

Larger flappers just get in the way of the exhaust. With a larger flapper, the exhaust has a larger obstruction to have to flow around.

Larger flappers allow for a larger wastegate passage to the flapper. The larger flapper gives you more room to allow and keep a seal over the passage. That is how it tried to get rid of creep


You are getting a bullseye turbo? or just the housing? If you want a wastegate on the manifold are you going to send it somewhere to be mounted? Clipping has nothing to do with boost creep its increases spool time for an increase in top end.

 

[beat90tsi]

my evo3 creeps like a whore as well
I have 02 elim, and put a cat in to help creep, but it still gets to about 20-22 by redline.
My cat isn't even 3", so it's definitely a cork in the system. I have knock pretty well under control at upper rpms with 255/650s and MAFT, but it's not perfect. I'm hoping with 1g dsmlink I'll be able to get rid of some of my extra timing and support 22+psi all the time, despite the creep, but I suppose it would be nice to have the option of setting the boost lower. Right now the only way for me to run less boost is to disconnect the WG from the flapper, and I still get a little boost at redline, maybe 5-6psi.

I guess evo3 creep is a major problem. I'll probably try porting the wg passage someday when I don't need my car and I can have it apart for a few days.

From what I've read on here, it seems like the larger flappers are a waste of time...is that correct?

 

[Ganja Man]

im just going to get the housing for the turbo and yes i would have the manifold sent off to get the wastegate mounted or i might just try and find one that all ready to go but whats a good company to send it to for the wastegate if i decide to do that? thanks

 

[flinguist]

This is the type of external waste gate setup that may not work, because you're using the turbo exhaust housing, waste gate flow is still limited by the size/configuration of the waste gate hole.

 

[flinguist]

I did a lot of searching and the only place that has a price quote for installing a wastegate on the manifold is Buschur Racing ($75 on a 2G mani.). http://www.buschurracing.com/cgi-bin/ez-catalog/cat_display.cgi?2X376545X50
I'm sure other reputable vendors would do it too ( Slowboy, RRE, RNR etc.), but you'll have to contact them for a quote.

 

[~laser_craver~]

it all depends on the amount of boost you wanna run a 38mm should be fine for allot the people here, isnt it good till like 24 psi?

ryan

 

[MrPikolo]

Larger flappers just get in the way of the exhaust. With a larger flapper, the exhaust has a larger obstruction to have to flow around.

If the turbo is properly setup for the flapper, it should help. It will allow you to run a larger wastegate hole to let out more exhaust gasses. And if the turbo is ported correctly to allow the larger flapper to get out of the way of the exhaust flow, it will be much better than a stock setup.

 

[jab-619]

Does anybody make a longer rod for the wastegate? Or one that has more travel? So that the flapper opens more. Just a Thougt.

 

[SlowboyCSE]

I'm now offering this if you want to get rid of boost creep.

This and a 34mm flapper will really give you rock solid boost control on a 16G style turbo.

If you have the tools, you can do this yourself. We do it on the bridgeport mill, then smooth everything in by hand.

Some folks call it "siameseing", others call it "merging". We use this in extreme cases of boost creep.

It works with O2 eliminators and O2 dump tubes, but it sounds bad because it's the same as having an exhaust leak up by the motor.

It will be on the website soon.

 

[SlowboyCSE]

Does anybody make a longer rod for the wastegate? Or one that has more travel? So that the flapper opens more. Just a Thougt.

I've tried this till i was blue in the face. Got no results. Always came back with the same results that a larger hole in the side of the housing helped greatly and in rare cases we merge the O2 Housing divider and if you want to run extremely low boost, we can remove the divider in the Turbine Housing as well. PTE does this on all of there internally gated cast mitsu turbine housings.

 

[jab-619]

WOW THAT WILL WORK ^^^^^
How much $$$

 

[ShapeGSX]

I'm now offering this if you want to get rid of boost creep.

This and a 34mm flapper will really give you rock solid boost control on a 16G style turbo.

If you have the tools, you can do this yourself. We do it on the bridgeport mill, then smooth everything in by hand.

Some folks call it "siameseing", others call it "merging". We use this in extreme cases of boost creep.

I dont see how a 34mm flapper can help at all with an Evo III 16G. You can't port the wastegate hole out that large. And now the exhaust has a huge flapper to have to get around.

And cutting back the metal between the wastegate and turbine exit may help with boost creep, but I'm not willing to sacrifice my turbocharger's efficiency. You are supposed to keep the wastegate and turbine paths seperate for as long as possible. Blowing the higher pressure wastegate gasses into the path of the turbine exhaust kills the flow of the turbine.

I'll live with the creep.

 

[ShapeGSX]

If the turbo is properly setup for the flapper, it should help. It will allow you to run a larger wastegate hole to let out more exhaust gasses. And if the turbo is ported correctly to allow the larger flapper to get out of the way of the exhaust flow, it will be much better than a stock setup.

Not on an Evo III 16G. There isn't enough metal around the wastegate hole to port it out too much without making it too thin for my comfort. And if that metal around the wastegate port cracks, you are screwed. You won't be able to hold or build boost correctly.

Making the wastegate rod longer won't help at all. The throw is defined by the throw of the actuator, not the length of the rod.

 

[truwarrior]

I'm now offering this if you want to get rid of boost creep.

This and a 34mm flapper will really give you rock solid boost control on a 16G style turbo.

If you have the tools, you can do this yourself. We do it on the bridgeport mill, then smooth everything in by hand.

Some folks call it "siameseing", others call it "merging". We use this in extreme cases of boost creep.

It works with O2 eliminators and O2 dump tubes, but it sounds bad because it's the same as having an exhaust leak up by the motor.

It will be on the website soon.

Got the 02 housing and I creep to atleast 20 psi... No flapper mod though... My boost gauge only goes up to 20psi. Did a 2nd gear pull, towards reline check engine light turned on (knock) and I cut the gas. I'm hopeing I was just running lean making to much power and causing the creep. Installing the fuel pump and injectors real soon.

 

[psychlow]

You have to wonder.

If we have this much trouble with EVO III 16G's on relatively stock (otherwise) 4G63's...

What the hell did Mitsubishi do to control them on EVO III's?!!? 1.5'' exhaust??