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Old 09-16-2002, 11:07 PM   #1
tntmstr
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Question BOOST CREEP ?!?! Vets. please help

A question for the gods on the board!! Just installed a VF-34
Running 15-16psi (trying to anyway)
Mods (relevant to situation)
Blitz SBC-id
MRT FMIC
PDE DP
Scooby sport UP
HKS Carbon-Ti CB
Blitz BOV
APEXi AFC
stock fuel

Problem is: Boost comes on like it should. As the RPM's climb, 5K+, so does the boost, Say top of 3rd hitting like 17ish PSI.
Top of fourth 18ish PSI. It holds up to around 5000rpm then proceeds to climb of the mark. So solution one was to turn down the setting on the SBC-id! The lower I went, the lower the boost was like it should be. BUT once I got in the 5-6000 rpm range there it went up to 17-18 PSI again. SO I thought turn the SBC-id off and then It can't run more than 8-9 psi right? Wrong, Held 8-9 psi, guess what, 5-6000 rpm climbed it's way up to 17-18psi again. OK, grabbed a Turbo XS MBC. Set it up, made some runs, Boost came on great, to like 15psi. Then like clock work. 5-6000 RPM there she goes back up to 17-18 psi. I played with it for a while and turned in the screw, SAME DARN THING!!! When the problem was first noticed I replaced the vaccum hoses to eleviate the question of a bad hose. Relocated the SBC-id solinoids, shortened the hose length, Checked and rechecked for other vaccume leak possibilities. NOW mind you I changed nothing else prior or durring the VF-34 installation. The SBC-id with the stock turbo worked beautifully. I called the boys at Vivid, they are calling to see if maybe there is a possibility of the waste gate actuator being bad. I am at a loss. I have a Autometer boost gauge as well as the Blitz EBC gauge and they are both right on. The car pulls like crazy, so I know It's actually raising the boost. ( that was their first question) I searched and found nothing that directly related to this kind of problem. So I was hoping one of you might have ran across this before.
PLEASE AND THANK YOU!!
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Old 09-16-2002, 11:36 PM   #2
suprasingle
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well im not a vet, at a wrx anyway,had one a month,but have the same problem,and i have come to the conclusion its the dp,i have a vf22 and a single dump dp.im searching for a twindump dm,

randy
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Old 09-16-2002, 11:44 PM   #3
tntmstr
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ok so why are we the only ones having this problem? I know there are quite a few out there running similar set ups like us with no issues at all. I don't really see what the twin dump will do. Unless there is a problem with the exhaust pressure not allowing the WG to open properly? What gives?
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Old 09-17-2002, 12:23 PM   #4
tntmstr
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come on guys!!! Anyone????????????
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Old 09-17-2002, 01:53 PM   #5
DeliciouSpeed
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Get a Twin dump downpipe. It really helps boost control a lot. I run the BPM unit.

Ken
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Old 09-18-2002, 02:52 AM   #6
tntmstr
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MRT said maybe the WG Actuator rod is bend a little. They recommended bending it a little toward the fire wall. It possibly is not opening all the way. If not the WG itself is defective. I will try this Wed. afternoon and post my findings.
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Old 09-21-2002, 09:00 PM   #7
tntmstr
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ok one more thing. MRT said run a vaccum line from the turbo outlet side directly to the WG. This produced the same affect, boost creep upto 17-18 psi Anyone ever have this problem?? MRT wants me to send back the turbo and have it checked out. I want to explore every option before I send it back for it's 3 week total voyage. There has to be a better answer than, I need a DP with a dump tube!
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Old 09-21-2002, 09:59 PM   #8
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Im not 100% sure but I adam (darthchicken) is experiencing this same type of behavior with his VF30...but his engine is an older style EJ20 with wrx heads running about 9:1 CR...

You might wanna send him a pm, but running 18psi on a VF34 isnt a bad thing UNLESS your on the stock fuel system!
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Old 09-22-2002, 12:12 PM   #9
tntmstr
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mlambert,
I know I can run 18psi+ on the VF 34, I am still waiting for my injestors till I turn it up. But I still "should" be able to turn down the boost to 9 or above. Have you tried turning yours down to say 13 and made some 3-4gear pulls to see if it holds? Maybe they just won't run any less and that's what I'm trying to figure out. My potential problem is once winter comes I am afraid I won't beable to turn it down enough for our 20-40 below winter days and nights here in North Dakota. It just doesn't seem right that I can't turn it down and make it hold even running the vaccum line directly from the trubo to the WG, it still creeps it's way upto 18+psi. If possible could you try turning yours down and see what happens? What DP and UP are you running? and what boost controller?
thanks,
shane
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Old 09-22-2002, 08:09 PM   #10
NotoriousWRX
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This sounds very odd. I would be very interested in the final outcome.
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Old 09-22-2002, 08:41 PM   #11
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Quote:
Originally posted by tntmstr
mlambert,
I know I can run 18psi+ on the VF 34, I am still waiting for my injestors till I turn it up. But I still "should" be able to turn down the boost to 9 or above. Have you tried turning yours down to say 13 and made some 3-4gear pulls to see if it holds? Maybe they just won't run any less and that's what I'm trying to figure out. My potential problem is once winter comes I am afraid I won't beable to turn it down enough for our 20-40 below winter days and nights here in North Dakota. It just doesn't seem right that I can't turn it down and make it hold even running the vaccum line directly from the trubo to the WG, it still creeps it's way upto 18+psi. If possible could you try turning yours down and see what happens? What DP and UP are you running? and what boost controller?
thanks,
shane
well its not my car, like i said, but hes running a perrin uppipe and a bpm downpipe and hes using an avc-r until his utec comes.
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Old 09-24-2002, 02:28 AM   #12
tntmstr
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ONE LAST SHOT, anyone have this problem or have an idea before I send the Turbo back to MRT? I hate to have them say there was nothing wrong with it and pay the $70+ in shipping,there and back! PLEASE SOMEONE!!!!!!!!!
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Old 09-24-2002, 06:59 AM   #13
JenisonWRX
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Does your controller say that it has the wastegate fully open?

That would be where I would start. If infact it says that the wastegate is open all the way and your still creeping ... then you have a problem.

and I don't doubt for one second that your NOT outflowing that wastegate.

esp with those mods you listed

I can get boost creep in the stock turbo ... that is if I don't want to hit 15psi
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Old 10-02-2002, 10:58 AM   #14
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I am having the same problem with the SBC iD, VF30 and a TWIN dump downpipe... the Vishnu Signature Series exhaust to be exact.

I turned off the controller which should allow air to pass straight through the solenoids to the actuator, same thing as if you would directly connect the turbo outlet to the actuator AND I too am seeing the same thing... 8psi down low (like it should be) and then as the rpms get over say 5k, the boost goes where it wants!!

I am gonna try connecting the actuator DIRECTLY to the turbo outlet and see what happens. If I get only 8psi or so to redline I know its the solenoids on the SBC (perhaps clogged with oil?) If there is no change then I would have to guess it would be the actuator.

Would the factory TD04L-13G actuator work on the VF30? Perhaps I should just swap them out...

Any input woud be highly appreciated!

Thanks,
def
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Old 11-30-2002, 01:27 PM   #15
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I did a search and came up with this post. I have the same problem with boost creep with similar mods. Seems like i can't turn down the boost. Please help!!! Any suggestions would be greatly appreciated.
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Old 11-30-2002, 04:22 PM   #16
MadWagon
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What about engine tuning? I noticed you are not doing anything for real engine management besides the AFC. The ECU is programmed for the stock turbo characteristics. Doesnt it advance quite a bit up top as it expects the boost to drop off? Who has decent aftermarket EM and still gets boost creep? Do dyno tuned guys still get boost creep?
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