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

 

[ShapeGSX]

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??

Maybe they just ran 20psi?

I don't see what the trouble is, personally. So it creeps a little in the cold weather. Makes for a fun car.

But you shouldn't be installing this turbo on a nearly stock car. Look at a stock Evo III. Is it anything like a stock DSM? Let's see: 550cc/min injectors, FMIC, different compression, different tuning in the ECU, larger exhaust, better O2 housing, a matching exhaust manifold, etc...

A stock DSM doesn't have the same stuff. You gotta expect some trouble. Especially if you want to run lower boost because you don't have the fuel system for 20psi.

 

[truwarrior]

I'm more worried about a headgasket

 

[truwarrior]

Any one ever have a really lean condition cause creep?

 

[SlowboyCSE]

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

It will be on the website shortly. Still playing with the jig that holds it in the mill and then being able to make it 100% reproducable is my quest right now. 2 weeks, it will be on the website!

Cragger

 

[jesepes]

Boost creep?? Do a quick test.

First, make sure your car's exhaust parts aren't going to burn you when you touch them. Then get a pair of pliers and "carefully" pull on the wastegate actuator shaft. Pull it until it is at full extend.

Then, look at how far your flapper arm (that the actuator is attached to) has moved. Remember this.

Now, disconnect the actuator from the flapper arm. Move the flapper arm all the way open with your fingers. Compare how far the actuator will open it to how much further it opens without the actuator connected. (Approximately 45degrees with actuator connected and over 90degrees disconnected.)

Next, be astounded, be amazed, be pissed you didn't think of this: http://www.dsmtuners.com/forums/showthread.php?t=156894 Or at least a close imitation. (I personally had a much more complex setup involving lever arm pivot lengths, but just as effective solution. Then "Pickens" showed me this.)

Finally make one, buy one, etc. and then put your car back together and enjoy less/no creep.

I have a 14b with factory exhaust (exceptions: ported 2g man., and ported turbine housing) and was creeping to 20+ psi in every gear I could hold traction(3rd and up) and with this simple mod and nothing else I returned to factory or close. I was at 10psi with NO creep. Everyone can than "Pickens" for his thread and answer. I hope it works out as well for everyone else as it did for me even though I'm only running a 14b not an e16g.

 

[truwarrior]

It will be on the website shortly. Still playing with the jig that holds it in the mill and then being able to make it 100% reproducable is my quest right now. 2 weeks, it will be on the website!

Cragger

Well it's not working very well for me

I'm gonna try and port that ridge out of the wategate hole some more right before the 02 housing meets the turbo...think that will will do it? Do you port out divider on the wastegate passage and turbine outlet on the evIII too?

 

[ShapeGSX]

A removable solution is a good idea, because you definitely wouldn't want to run something like that when you are racing.

Somebody build it.

 

[RU2SLOW?]

Why do I hear all of these people complaining that the 34 mm flapper flies open above 20 psi and gives them problems? Is it because the flapper is too small still, or can this too be fixed with some porting? I want to get the flapper mod, but I don't want to have problems when I turn up the boost.

Also, would the stock flapper actually be better with some porting at high psi- 20 lbs and up?

 

[GRNDSM]

Why do I hear all of these people complaining that the 34 mm flapper flies open above 20 psi and gives them problems? Is it because the flapper is too small still, or can this too be fixed with some porting? I want to get the flapper mod, but I don't want to have problems when I turn up the boost.

You need more force to keep a larger flapper from “blowing open”, but since most people still use an original wastegate actuator, they do not have anything extra. So they tend to blow open. Also, at higher boost levels you tend to rely on WG being closed. So that is when it is noticeable. The way that you get low boost level is by controlled opening of the WG hole.

Also, would the stock flapper actually be better with some porting at high psi- 20 lbs and up?

A stock flapper would be better PERIOD….

See: http://www.dsmtuners.com/forums/showthread.php?t=163103

 

[RU2SLOW?]

You need more force to keep a larger flapper from “blowing open”, but since most people still use an original wastegate actuator, they do not have anything extra. So they tend to blow open. Also, at higher boost levels you tend to rely on WG being closed. So that is when it is noticeable. The way that you get low boost level is by controlled opening of the WG hole.



A stock flapper would be better PERIOD….

See: http://www.dsmtuners.com/forums/showthread.php?t=163103

Thanks for this reply- this is VERY helpful in trying to understand this subject. So what you are saying is a 38mm flapper shouldn't been considered as a solution for higher boost applications because it will take even more force to hold this one down than the 34 mm- without the proper actuator to do so? That would mean that if I wanted to run 22 psi on the stock flapper I would most likely have a better chance of not seeing boost creep at higher levels than with the 34mm?

 

[~laser_craver~]

ok i have decided to stay with my big 16g and have it ported out and run an external wastegate on the o2 with a atmo.dump... and 2.5 turboback exhaust from rnr... i think this will eliminate my boost creep... do you guys think it will

ryan

 

[fr33b1rth]

another good solution to boost creep is to get an external dump.....

BUT MOST DON'T LIKE THIS!!!

An external dump help reduce boost creep by letting the wastegate gasses exit more efficiently, and stock o2 housings just dump the gasses into the exhaust and let it miz around creating turbulance. Take an external dump, take it to a exhaust shop and have them run a pipe from the external dump down to about the cat, and have them cut a hole into your exhaust and weld the dump tube in there. This way the gasses will still flow freely, and they still go into the exhaust!

Am i the first one on this board to suggest this?

 

[Empyrials]

On my BIG 16G i have mad Boost creep probs...

1st gear i have it set to about 12.. it'll creep to about 13-14
2nd gear it'll stay about about 14 it'll creep to about 15-17
and 3rd it'll creep to about 17-20
4th i shift hella early... too much boost..


I have an O2 Dump and no Cat, however i have stock exhaust, but the O2 dump should do something

any ideas??¿¿¿

 

[GRNDSM]

On my BIG 16G i have mad Boost creep probs...

1st gear i have it set to about 12.. it'll creep to about 13-14
2nd gear it'll stay about about 14 it'll creep to about 15-17
and 3rd it'll creep to about 17-20
4th i shift hella early... too much boost..


I have an O2 Dump and no Cat, however i have stock exhaust, but the O2 dump should do something

any ideas??¿¿¿

Is your 16G exhaust housing ported?
Why are you running such low boost? (the higher the boost, the less boost creep you will see)

Leon

 

[RossY]

Is your 16G exhaust housing ported?
(the higher the boost, the less boost creep you will see)
Leon

of course, if you creep to 20lbs then you'll only see 2lbs of creep if you set your mbc to 18lbs. at 10lbs you'll see 10lbs of creep. I think im going to do some port work to my turbo and o2 housing as well as the pickens thingy.

My 1g valve was leaking at 20lbs but since i installed a greddy bov, i see what the turbo has really been pushing. 26lbs of boost in every friggin gear. by about 4500rmps, boost almost instantly creeps to 26psi from 10psi in 2nd gear and up no matter what. The pull is amazing but i would like to keep my engine a little while longer.

After reading this whole post i feel like my engine/turbo is performing well since i get insane creep though

 

[oldman]

of course, if you creep to 20lbs then you'll only see 2lbs of creep if you set your mbc to 18lbs. at 10lbs you'll see 10lbs of creep. I think im going to do some port work to my turbo and o2 housing as well as the pickens thingy.

My 1g valve was leaking at 20lbs but since i installed a greddy bov, i see what the turbo has really been pushing. 26lbs of boost in every friggin gear. by about 4500rmps, boost almost instantly creeps to 26psi from 10psi in 2nd gear and up no matter what. The pull is amazing but i would like to keep my engine a little while longer.

After reading this whole post i feel like my engine/turbo is performing well since i get insane creep though

Not what he meant. If you set the mbc at 14psi and it creeps to 20psi, It is very possible that if you set the boost at 18psi, you'll see no creep at all. Your problem doesn't sound like creep at all. I would check for faulty actuator and hoses around the mbc/wastgate area before you start taking the turbo apart.

 

[beat90tsi]

I'm creeping past 25psi in this colder weather in 3rd and above. With a cat in, I could keep it to 20, but without the cat, it's going hog-wild. I even ported my WG passage and opening when I had the turbo off. I think I need to try that flapper arm mod.

 

[oldman]

I'm creeping past 25psi in this colder weather in 3rd and above. With a cat in, I could keep it to 20, but without the cat, it's going hog-wild. I even ported my WG passage and opening when I had the turbo off. I think I need to try that flapper arm mod.

I have not read this thread in a while but I'm sure this was mentioned before: You need to ease the entrance path to the wastgate passage by knocking off the material on top of your wastgate at the turbine inlet. Without doing this, even a o2 dump couldn't help you.

 

[RossY]

Not what he meant. If you set the mbc at 14psi and it creeps to 20psi, It is very possible that if you set the boost at 18psi, you'll see no creep at all. Your problem doesn't sound like creep at all. I would check for faulty actuator and hoses around the mbc/wastgate area before you start taking the turbo apart.

The actuator works fine and the hoses are connected correctly. At 10 psi the wastegate opens and holds up till about 4300rpms. After that it just creeps up to 25-26psi. As a side note, it is about 28degrees out right now.

 

[beat90tsi]

I took a good bit of material from the entrance, but I guess not enough.

 

[1grrvalley]

no good

 

[oldman]

The actuator works fine and the hoses are connected correctly. At 10 psi the wastegate opens and holds up till about 4300rpms. After that it just creeps up to 25-26psi. As a side note, it is about 28degrees out right now.

Well, get that die grinder ready then.

 

[oldman]

I took a good bit of material from the entrance, but I guess not enough.

When I look straight down the inlet I can see more then 50% of the wastgate hole. 12 psi to redline, used to creep to 24psi by 5k. Take off more material while keeping the overall cone shape as smoth as possible and you should be fine, make sure you also port the wastgate oulet and o2 housing per vfaq as well.

 

[droptopgst]

I had the boost creep problem with my TD05 18g until I ported, clipped, and got the 34mm w/g. Now no creep what so ever and I have boosted up to 25psi