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Old 10-11-2009, 11:36 PM   #1
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Default what fixes for boost creep?

After being gone for a year, I'm trying to sort out my car again. My biggest problem at the moment is boost creep. While I was gone, my car was used for the FM 3" exhaust prototyping which was then installed on my car. I expect that the 3" exhaust has caused the boost creep problem. The three solutions that I have seen on the forum are:

1: port the wastegate
2: external wastegate
3: restrict the exhaust flow

I took out my MBC to help with the problem, I now have my full RPM range back (was hitting boost cut on the Hydra at about 6k rpms) but even without the MBC, boost starts creeping pretty bad beyond the base 8psi at about 4k rpm, and is at full 14-15psi by redline.

I will be driving from LA to Columbus, OH starting on the 15th of this month to return home, so shipping parts out and back isn't an option right now, and I've got to go > 2,000 miles reliably on the equipment I've got. I'm looking for any possible solutions that I haven't covered. Could my wastegate or actuator be not functioning correctly? The car has probably been sitting still since about April, could rust be a consideration? Is this something that can be cleaned up?

Or do I just have to deal with it and be easy until I get home to start an engine build and look to switch to an external gate?

Turbo is an FM 2560 + associated wastegate hardware.

If nothing else, I'll give FM a ring on Monday and see what they say
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Old 10-11-2009, 11:42 PM   #2
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You already know almost every solution it looks like.
3rd one really isn't a solution as much as just a band aid though. ewg is probably best. Porting the iwg is next.

OR you could just make your car handle the big boost
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Old 10-11-2009, 11:44 PM   #3
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Parts to handle the big boost are waiting at home....but I've got to drive what i've got across the country first Then starts the fun.
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Old 10-11-2009, 11:54 PM   #4
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Just started a thread on this a week ago after taking my car to the dyno... Porting is the only answer outside of an ewg that you will get from anyone. Blouch is supposed to be the definitive and I will be sending them my hotside within the next week or two.
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Old 10-11-2009, 11:54 PM   #5
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I wouldn't think the downpipe would do that. I would of thought the dp would let more air flow, and less boost back up. But I may be wronge.....Someone correct me if I am. I'm curious.......
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Old 10-11-2009, 11:57 PM   #6
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The only other option is having an external dump for the internal wastegate, similar to what you would do with an external wastegate. Im going to do this to my setup soon in hopes of curing my insane boost creep
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Old 10-12-2009, 12:03 AM   #7
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Quote:
Originally Posted by Toddcod View Post
I wouldn't think the downpipe would do that. I would of thought the dp would let more air flow, and less boost back up. But I may be wronge.....Someone correct me if I am. I'm curious.......
wrong.
more flow overwhelms the wastegate flapper/port causing the turbo to "overspin" so to speak and to boost creep.
Quote:
Originally Posted by Full_Tilt_Boogie View Post
The only other option is having an external dump for the internal wastegate, similar to what you would do with an external wastegate. Im going to do this to my setup soon in hopes of curing my insane boost creep
That is a waste of money and completely stupid IMHO. You'll have to port the iwg port in order for this to work even SORT OF properly, and still end up with the extra cost and weight of an ewg with none of the benefits. Its not the actual flapper that is causing the creep. It's the size of it and the port its closing/opening.
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Old 10-12-2009, 02:28 AM   #8
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Quote:
Originally Posted by 18psi View Post
That is a waste of money and completely stupid IMHO. You'll have to port the iwg port in order for this to work even SORT OF properly, and still end up with the extra cost and weight of an ewg with none of the benefits. Its not the actual flapper that is causing the creep. It's the size of it and the port its closing/opening.
Im not saying to mount an external wasegate on the downpipe flange, i agree that would be stupid. what Im reffering to is making the tube coming from the internal wastegate dump to atmosphere instead of venting into the high pressure environment in the downpipe.
Im running a restrictive naturally aspirated exhaust so it should be an improvement, the gains would probably be minimal with a free flowing exhaust.
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Old 10-12-2009, 02:57 PM   #9
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A WG dump tube can also lead to boost creep.
Stephanie
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Old 10-12-2009, 03:04 PM   #10
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Quote:
Originally Posted by flipt86 View Post
Just started a thread on this a week ago after taking my car to the dyno... Porting is the only answer outside of an ewg that you will get from anyone. Blouch is supposed to be the definitive and I will be sending them my hotside within the next week or two.
Corky started porting our turbos 3 years ago to eliminate the boost creep (since we did not handle the turbos when FM sold BEGI ktis). If you want to get real technical we've ported turbos since the mid 90's. So Blouch could probably back up our story, along with turbochargers.com. And we port them for free.

Corky's porting seems to do the trick. UNLESS..... you are using a electronic boost control solenoid. If you are using a EBC unhook it and run off of straight actuator control.

OP- if you are worried about boost creep, your only temporary solution is to unhook the actuator and run boost-less. No fun, I know, but the safest temporary solution.
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Old 10-12-2009, 04:32 PM   #11
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Quote:
Originally Posted by Stephanie Turner View Post
Corky's porting seems to do the trick. UNLESS..... you are using a electronic boost control solenoid. If you are using a EBC unhook it and run off of straight actuator control.

Stephanie
do yall port the turbo's for the S1 kit?
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Old 10-12-2009, 04:39 PM   #12
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Quote:
Originally Posted by 18psi View Post
wrong.
more flow overwhelms the wastegate flapper/port causing the turbo to "overspin" so to speak and to boost creep.
instead of overwhelms, how about completely bypasses...

The design of the integrated wastegate is flawed. When gases have such an easy time flowing out through the turbine itself, the don't want to actually make their way out the wastegate section. This is due to the shape, size, angle of the wastegate output.
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Old 10-12-2009, 06:27 PM   #13
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Can't you just drive home without flooring it? I've done this before when my ball and spring boost controler came apart and I lost the cap, ball and spring.
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Old 10-12-2009, 07:44 PM   #14
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yup, thats the plan right now

gonna be a boring 2,000 miles
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Old 10-12-2009, 08:05 PM   #15
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Quote:
Originally Posted by Stephanie Turner View Post
Corky's porting seems to do the trick.
I vouch. Worked great on my turbo (internal WG.)
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Old 10-12-2009, 08:35 PM   #16
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I'm interested to know if JRW's 2560 he has on his S1 kit was ported, because on the same day on the same dyno, his car was creeping just as much as mine. If his was ported by Bell, it didn't solve much. I tend to believe it has not been ported, but we won't know until he yanks the hotside.
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Old 10-12-2009, 09:40 PM   #17
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Old 10-13-2009, 10:18 AM   #18
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Hustler, weren't you just posting about boost control issues?
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Old 10-13-2009, 12:17 PM   #19
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Quote:
Originally Posted by flipt86 View Post
I'm interested to know if JRW's 2560 he has on his S1 kit was ported, because on the same day on the same dyno, his car was creeping just as much as mine. If his was ported by Bell, it didn't solve much. I tend to believe it has not been ported, but we won't know until he yanks the hotside.
If it was sold as a complete S1 system, then yes it was ported. You can look at the turbine housing and tell for sure. Are you using an EBC?
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Old 10-14-2009, 11:43 AM   #20
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mine is a full S1 kit. I'll try and call later today a discuss it further. thanks Stephanie...
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