Boost Creep (oldman read this)

[~laser_craver~]

Ok so i have massive amount of boost creep. And after seeing what oldman walked many people threw i took the turbo off my car and grabbed the dremel. Well as many people have stated its very addicting. And me using a dremel made it take forever but i think i might have it doe or close to it now. Oldman grade me please.

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Thanks

Ryan

 

[oldman]

You're such a dork, at least send me a pm next time.

Turbine inlet : C+. I would like to see the step on the flange completely gone and the whole thing blended in from the flange area, enlarge the inlet some more but make sure the EVO3 manifold collector as well as the gasket matches the work on the turbine inlet. The most crucial area, on top of the wastegate entrance, looks to be about 80% finished, there are some more room to go. Your inlet should look exactly like the picture in this tech article.

Wastegate outlet : B-. Flapper definitely opens enough but I would like to see the actual waste hole enlarged, make sure you leave enough room on all sides of the flapper to ensure proper sealing. The outlet area can also use some more porting near the center divider like described in this vfaq.

Not too bad so far especially with a dremel.

 

[~laser_craver~]

Ok thanks ill go to the garage and work on that right away. Expect more pictures tonight .

 

[~laser_craver~]

Ok Ive been working on it some more and hope its done because Im so full of metal shavings I could pull an entire turbo out my arse at the moment. But I want you to realize oldman that I am not trying to gain any spoolup or power by doing this I am strictly doing this to elminate my boost creep. I really want to be able to pull all of 3rd 4th and 5th gear instead of just half.....

This time around I mainly focused on removing material around the waste gate hole. The hump in the inlet and the excess material near the flapper. After that I turned my attention slightly to smooth out the transition between the flange and the turbo inlet itself.

That being said heres the update lemme know how this is.

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[daren_p]

It looks like you have but its hard to tell from the pic. On the wg outlet, looking at you second pic (origional post) did you remove the protruding lip that extends from the left side to the top? This is the area where the exhaust gas will flow directly into through the wg and from the factory basically hits a 90 deg wall. When I did mine I made this area a nice smooth curve instead of a flat wall. I can post some pics of my porting if your interested. I did mine & a buddies the exact same way and we can both hold 14 psi with zero boost creep, I have a 3" HF cat but he is 3" straight through.

Edit: Looks like you posted some more pics before I finished my post. Looks like the are that I was talking about is completely removed (your third pic in the last post) The wg hole still looks abit small to me, do you have the 34mm flapper? Also you don't need to worry about the wg flapper opening all the way as the wg actuator on the evoIII (that is an evoIII, correct?) will only move the flapper about 3/4's of the way open, when its fully extended.

Does the flapper cover right to the raised area on the turbine housing? If so I would port out the top/bottom of the wg hole to look more like it does in the left/center part of the 3rd pic.

 

[dustyb]

imo i'd make the wastegate exit a bit bigger, how much did you port it out?

 

[~laser_craver~]

No, its a B16g and yes i ported out the w/g exit. I removed quite a bit of material actually but there is room for more to be removed.

 

[LA97GST]

Yes a bigger WG exit would be great, but you must know when to stop. It is easier to pull turbo off and port exit more than overport and have a leak which is not repairable.

 

[~laser_craver~]

I went out to the garage and used my last sanding drum to enlarge the w/g exit hole. It is now to the point where if i grinded anymore off the flapper wouldnt seal. And to answer the other question no i dont have a 34mm flapper its just the plane jane run of the mill B16g other then the fact that i spent the last 2 days porting the hell out of it. But do you all think that now i will have eliminated my boost creep? Because that is my only concern if i wanted it to spool faster or w/e i woulda had the company i bought it from do it to begin with. I just dont want boost creep anymore and i dont see spending the money on external.

 

[Quasimondo]

If you're still creeping, the next step is more porting and replacing that flapper with a 34mm piece.

 

[oldman]

I would have taken out more on top of the wastegate entrance at the inlet but if you ran out of tools, let's bolt it on and see. How bad were you creeping and how much pressure are you planing to run?

 

[~laser_craver~]

Before i took the turbo off i had the boost turned all the way down to the lowest i could. Which if memory serves me correctly is 8 psi due to the actuator not being able to go any lower. But the boost gauge (phantom series autometer) said 10-11. It would hold that in 1st all te way to redline aswell as 2nd all the way to redline. But in third at about 5200-5500 it would begin to creep. It creeped to 17-18 psi in third and hit fuelcut. And hit fuelcut at the same amount of boost in 4th and 5th. But in 4th and 5th it hit sooner in the rpm range. Currently i have a stock down pipe stock catback, a magnaflow muffler and a 3 inch testpipe.

 

[oldman]

But in third at about 5200-5500 it would begin to creep. It creeped to 17-18 psi in third and hit fuelcut.

And at what rpm does it hit fuel cut?

Basically you got two issues here, boost leaks and boost creep, boost leaks because you shouldn't be hitting fuel cut at 18psi. Good news is, the porting you have done should be able to cure your moderate level boost creep.

 

[~laser_craver~]

There are absolutely no boost LEAKS. Tested it before i took the turbo off. I would hit fuelcut in 3rd around 6200-6500. So in roughly 1000 rpms it climbed about 6-7 psi. I am on stock fuel delivery with a maft blow thru setup. My base injector size is set at 470cc injectors, because when set at 450's hit fuelcut just after hitting full boost and i was told that the maft sometimes has to be set a little off to actually be right on.

 

[tstkl]

very interesting.... I'm having the same problems...

When my car was completely stock I would hit fuel cut at 18 psi as well. I don't remember the rpm or gear, but that was the same psi. Maybe your just underestimating the 14b oldman. Actually, my o2 is reading .93 on those wot pulls where I hit fuel cut, so leaning it out was a must.

what are your other maft settings?

currently I am at +25% idle, -5% mid, -10% wot, but the last time I drove it I had it set to +30% idle, 0% mid, 0% wot, and hit fuel cut at 10psi in 3rd gear at 3875 rpm's

Its good to know someone else needs to lean there car out as much as I do, I know every car is different, but most of us should be seeing similar numbers on the maft since it goes by 5%, which is a lot imo.

 

[oldman]

My base injector size is set at 470cc injectors, because when set at 450's hit fuelcut just after hitting full boost and i was told that the maft sometimes has to be set a little off to actually be right on

maft in a blow through setup are known to read higherair flow than actual air flow, this is probably the reason why you're hitting fuel cut early. Do you have a logger or wideband O2? You probably have to adjust it more but not without a logger. BTW, fuel cut is not triggered by running out of fuel, it's triggered by air count.

 

[~laser_craver~]

I just used the last bit of grinding stones and sanding drums to get rid of a little bit more material above the entrance of wastegate area and now im out of stuff so. But your pretty sure that what i ahve done will elminate my boost creep? As far as my maf setting i am at base 4 aux 2 idle mid and wot are all 0 i am running it right before the tb elbow and im using a 3 inch mas. Before i had it set at aux 2 base 2 and i would start boosting and either at or just before full boost (11) it would hit fuel cut. So i talked to pina motorsports and Ryan walked me threw trouble shooting it and we ended up with it running perdy dam good at base 4 but then i tried dropping it to 3rd on the highway and discovered my boost creep. I plan on setting the boost around 15 after i fix the creep.

 

[tstkl]

maft in a blow through setup are known to read higherair flow than actual air flow, this is probably the reason why you're hitting fuel cut early. Do you have a logger or wideband O2? You probably have to adjust it more but not without a logger. BTW, fuel cut is not triggered by running out of fuel, it's triggered by air count.

Why couldn't you have said that the other night when we were talking about my fuel cut problems?

I still have my maft set for 450cc injectors since I have to compinsate in both directions so much. A new cast manifold without a crack will reveal what I'm actually reading at idle.

Not sure if your talking to me, but yes I have a logger

 

[~laser_craver~]

I have no logger or wideband.

Set your maf at base 4 and see if that get rid of your fuelcut it sounds exactly like mine was acting. And thats what i found to work. Either try a higher rated injector size or lower. Trial and error it till it works. If you hitting fuel cut at 10psi then your maf is not setup correctly. That is if you have no boost leaks etc. Hope i helped.

 

[TimG]

When I had an insane amount of creep from an EVO 16G on a 95 TSi AWD, I did all the turbo porting possible and it still creeped to 30+psi. I wanted to make sure the wastegate actuator was opening 100% of the way to ensure no creep.

I tried to add compressed air to the wastegate actuator and I noticed it was only opening up a small amount. Not even close enough for the flapper to hit the other side of the wall like you have pictured there (90 degrees). It opens more like 35-40 degrees, which is apparently normal for all Mitsu turbos.

So what did I port? The O2 housing. I ported the hole for the wastegate right where all the gated air enters the downpipe, 2 inches or so before O2 housing outlet. Presto, she holds at 17psi in every gear without fear.

My friend had even more trouble with his though. He ended up cutting the FLAPPER arm, shortening it by I believe 3/16th or so and welding it back on. It gave the flapper a few more degrees of opening and cured his creep as well.

 

[oldman]

Why couldn't you have said that the other night when we were talking about my fuel cut problems?

I still have my maft set for 450cc injectors since I have to compinsate in both directions so much. A new cast manifold without a crack will reveal what I'm actually reading at idle.

Not sure if your talking to me, but yes I have a logger

Because I just learn that helping another guy this week who was hitting fuel cut at 10psi @3500rpm so I asked him to tell me what the mafs reading was at the point of fuel cut and it was 1599Hz+ , My GT12 hit 1625Hz at 17psi and 6200 rpm.

 

[~laser_craver~]

I just looked at my flapper and put the o2 on etc. My flapper is ever so close to touching the o2 when fully opened but it does not touch. So i beleive my boost creep will be cured.

 

[oldman]

I just looked at my flapper and put the o2 on etc. My flapper is ever so close to touching the o2 when fully opened but it does not touch. So i beleive my boost creep will be cured.

Don't Jinx yourself, put it on and see.

 

[~laser_craver~]

Im waiting on some new turbo bolts and o2 housing bolts i had 2 break.... Plus i wanna replace the o2 housing and downpipe gaskets, i already have a new turbo gasket.

 

[tstkl]

hope I dont start getting boost creep as well...

I remember someone posting a 30 dollar kit that was supposed to make your flapper open twice as much or something, I'll try and find it for you guys. (I know you guys solved your problems, but for people searching for asnwers, heres another choice)

HAHAHA (that took so much longer than it should have, I even posted in the thread and I still couldn't find it fast, sad)

http://dsmtuners.com/forums/showthread.php?t=214269&highlight=boost+creep

http://www.dpconcepts.com/BoostCreepKit.html

I haven't used this, and I don't know if it works, but sounds like you can just drill a hole so that the arm of the flapper is shorter and it should open more.