Boost creep with stock turbo....
Jun 13, 2006, 09:34 AM
#16
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I have a 10.5 so I am upgraded. Single flapper too. I still have to install this stuff but am waiting for my extra mani and hotside to be ported/coated by BR and I need a boost guage and tune as well. I am seriously debating selling my coated O2 and not bothering with it.
Jun 13, 2006, 11:15 AM
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Thought I'd post this for good archival information. Borrowed from Garrett:
Boost creep is a condition of rising boost levels past what the predetermined level has been set at. Boost creep is caused by a fully opened Wastegates not being able to flow enough exhaust to bypass the housing via the Wastegates itself. For example, if your boost is set to 12psi, and you go into full boost, you will see a quick rise to 12 or 13psi, but as the rpm's increase, the boost levels also increase beyond what the boost controller or stock settings were. Boost creep is typically more pronounced at higher rpm's since there is more exhaust flow present for the Wastegates to bypass.
Effective methods of avoiding or eliminating boost creep include porting the internal Wastegates opening to allow more airflow out of the turbine, or to use an external Wastegates.
Effective methods of avoiding or eliminating boost creep include porting the internal Wastegates opening to allow more airflow out of the turbine, or to use an external Wastegates.
Jun 13, 2006, 11:23 AM
#20
Originally Posted by Soon2BEVO
I think the real culprit is the design of the Ebay 02 housing. The first thing I said when I looked at it was "how the hell is this NOT going to boost creep". Im referring to the hole where the wastegate exhaust flows into the turbine exhaust path .....it is the size of a nickel!
This pic shows the size of the hole.... that is TINY!
The part where the wastegate on the turbo is exits very large then has to go down to fit in that little hole. Not to mention there is no flow charactertistics what so ever inside it. There are creases even under the little hole. I guess thats why its $50-90 though!
For the record, I only recieved boost creep in 4th gear on EXTREMELY cold days if I did a 4th gear pull. Instead of doing traditional spike of 24.. then hit 22 and hold then bleed to 19 it would do this : spike 24... go to 22... back up to 23-24 then bleed down to 20-21 by redline. Nothing too bad and who knows, maybe it made my car faster!
I dont tihnk its the wastegate design purely because in essence both designs do the same thing, but who knows!
This pic shows the size of the hole.... that is TINY!
The part where the wastegate on the turbo is exits very large then has to go down to fit in that little hole. Not to mention there is no flow charactertistics what so ever inside it. There are creases even under the little hole. I guess thats why its $50-90 though!
For the record, I only recieved boost creep in 4th gear on EXTREMELY cold days if I did a 4th gear pull. Instead of doing traditional spike of 24.. then hit 22 and hold then bleed to 19 it would do this : spike 24... go to 22... back up to 23-24 then bleed down to 20-21 by redline. Nothing too bad and who knows, maybe it made my car faster!
I dont tihnk its the wastegate design purely because in essence both designs do the same thing, but who knows!
The WG dump hole is larger than a silver dollar. They do not boost creep. We use it to about 540whp, 127.62mph traps on a 2005 Evo.
I have tons of hi res photos, including the one your "borrowed" from me. I believe that this unit will outperform the WORKS unit and be real close to the Invidia.
Jun 13, 2006, 11:51 AM
#21
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Originally Posted by TTP Engineering
Its either your boost controllers, the size of vacuum tubing being used for the controllers or preload on the WGA.
The WG dump hole is larger than a silver dollar. They do not boost creep. We use it to about 540whp, 127.62mph traps on a 2005 Evo.
I have tons of hi res photos, including the one your "borrowed" from me. I believe that this unit will outperform the WORKS unit and be real close to the Invidia.
The WG dump hole is larger than a silver dollar. They do not boost creep. We use it to about 540whp, 127.62mph traps on a 2005 Evo.
I have tons of hi res photos, including the one your "borrowed" from me. I believe that this unit will outperform the WORKS unit and be real close to the Invidia.
Of course there is no boost creep with 540whp. Thats at very high boost. Its a weird phenomenon because SOME guys have it, SOME dont. I have a Hallman MBC, another guy I Know having the problem had a Forge. Like I said before as well, my car ONLY creeped 1-2psi in extremely cold weather. Its not a problem really, just somethign I noticed.
In the last 3-4 months the car hasnt creeped ONCE.
Jun 13, 2006, 11:54 AM
#22
I run 20-21psi on the street however. No creep.
I would be more prone to believe a 2003-2004 9.8cm2 might have an issue, not a 2005+. Regardless, anytime I read a thread about boost creep, near the end you always find out that there was some other cause.
I would be more prone to believe a 2003-2004 9.8cm2 might have an issue, not a 2005+. Regardless, anytime I read a thread about boost creep, near the end you always find out that there was some other cause.
Jun 13, 2006, 02:38 PM
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Originally Posted by TTP Engineering
Its either your boost controllers, the size of vacuum tubing being used for the controllers or preload on the WGA.
The WG dump hole is larger than a silver dollar. They do not boost creep. We use it to about 540whp, 127.62mph traps on a 2005 Evo.
I have tons of hi res photos, including the one your "borrowed" from me. I believe that this unit will outperform the WORKS unit and be real close to the Invidia.
The WG dump hole is larger than a silver dollar. They do not boost creep. We use it to about 540whp, 127.62mph traps on a 2005 Evo.
I have tons of hi res photos, including the one your "borrowed" from me. I believe that this unit will outperform the WORKS unit and be real close to the Invidia.
Jun 13, 2006, 03:05 PM
#26
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Originally Posted by TTP Engineering
Regardless, anytime I read a thread about boost creep, near the end you always find out that there was some other cause.
Jun 13, 2006, 03:09 PM
#27
Originally Posted by Soon2BEVO
The 02 went on my car alone. The car never creeped before it, only after... so all of a sudden my WGA isnt preloaded correctly or my MBC is faulty? I dont think so. Its definitely the 02. Like I said, it ONLY HAPPENED in FREEZING (below 20* F) conditions, no other times. I really dont care as the 02 added great power and no ill-effects.
Many things happen. One of which is your WGA is frozen and the diaphram is hardened increasing the load on the actuator.
Jun 13, 2006, 03:13 PM
#29
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Originally Posted by TTP Engineering
You are the 0.0034% of the Evo world that has even driven in sub 20*F weather.
Many things happen. One of which is your WGA is frozen and the diaphram is hardened increasing the load on the actuator.
Many things happen. One of which is your WGA is frozen and the diaphram is hardened increasing the load on the actuator.
Ok but I drove the car without the car all last winter without it and it never creeped...
Jun 13, 2006, 04:23 PM
#30
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I found a few one ebay but I dont know which piece is the correct one. ssautochrome didnt have any listed. Is this the right one?
http://cgi.ebay.com/ebaymotors/Turbo...spagenameZWDVW
http://cgi.ebay.com/ebaymotors/Turbo...spagenameZWDVW