Downpipe and Midpipe together
12-30-01, 12:45 PM
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Downpipe and Midpipe together
Will I be fine with downpipe and midpipe together? I heard of boost creep if have both. Is that true? Please help
1FAST7
1FAST7
12-30-01, 01:15 PM
#4
OG
Honestly every car is slightly diff, but chances are you will experience it...what some have done is port the wastegate...basically enlarging it's size.. This will generally work if you turbo's are stock...but if you port the turbo's too..especially both of them...then you chances decrease of holding down the boost..but then again when you port the turbo's you wanna run more boost anyways...
12-31-01, 07:22 AM
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No, pills don't affect creep. Porting the wastegate, getting an external wastegate ($$$), or adding exhaust restriction (cat or metal plates in-line) are the only real ways of preventing boost creep. I ported my wastegate. Pain in the ***, but definitely worth it.
~Tom
~Tom
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12-31-01, 09:26 AM
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It generally occurs on colder days when everything is more efficient. I have a little theory running around that those without boost creep with standard wastegate and full exhaust have less efficient turbos or turbo control system. Just a theory, but think about it. Also, you won't notice it too much if you're just in the primary turbo. Typically takes the flow of both primary and secondary to outflow the wastegate.
~Tom
~Tom
12-31-01, 09:46 AM
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the obvious solution is to set your boost controller a little conservative, to allow for some creep.....is preventing boost creep really worth 40 hours of labor to port the freakin wastegate? heck no! a little creep isn't going to hurt anything if you adjust for it....it even helps in drag races 
I never get more than about 1 psi creep anyway
I never get more than about 1 psi creep anyway
12-31-01, 09:54 AM
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It generally occurs on colder days when everything is more efficient. I have a little theory running around that those without boost creep with standard wastegate and full exhaust have less efficient turbos or turbo control system. Just a theory, but think about it. Also, you won't notice it too much if you're just in the primary turbo. Typically takes the flow of both primary and secondary to outflow the wastegate
"less efficient turbos"? this is counter intuitive and contradicts your opening statement ....think about it....I would think that the turbos are MORE efficient if you are getting creep, becasue they are developing MORE pressure than the wastegate can release...I don't think the stock control system/ECU has much to do with it
I guess this is a primary advantage of the Power FC, you can alter the wastegate duty cycle and thereby increase/decrease boost....refer to the R.R. site for how the stock ECU controls boost by "blindly" cycles the wastegate contol solenoid open and closed at a "mapped" rate to control boost
"less efficient turbos"? this is counter intuitive and contradicts your opening statement ....think about it....I would think that the turbos are MORE efficient if you are getting creep, becasue they are developing MORE pressure than the wastegate can release...I don't think the stock control system/ECU has much to do with it
I guess this is a primary advantage of the Power FC, you can alter the wastegate duty cycle and thereby increase/decrease boost....refer to the R.R. site for how the stock ECU controls boost by "blindly" cycles the wastegate contol solenoid open and closed at a "mapped" rate to control boost
Last edited by yzf-r1; 12-31-01 at 09:57 AM.
12-31-01, 11:17 AM
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Originally posted by yzf-r1
"less efficient turbos"? this is counter intuitive and contradicts your opening statement ....think about it....I would think that the turbos are MORE efficient if you are getting creep, becasue they are developing MORE pressure than the wastegate can release
"less efficient turbos"? this is counter intuitive and contradicts your opening statement ....think about it....I would think that the turbos are MORE efficient if you are getting creep, becasue they are developing MORE pressure than the wastegate can release
Originally posted by ME!
I have a little theory running around that those without boost creep with standard wastegate and full exhaust have less efficient turbos or turbo control system.
I have a little theory running around that those without boost creep with standard wastegate and full exhaust have less efficient turbos or turbo control system.
Restated: No Creep? Less Efficient Turbos.
Thanks.
~Tom
12-31-01, 11:29 AM
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how much does it cost to port the wastegate? and will porting the wastegate end boost creep totally from having dp, md,cb all together?
1FAST7
1FAST7
Last edited by 1FAST7; 12-31-01 at 11:36 AM.
12-31-01, 01:14 PM
#16
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The following statement may not apply to everybody, but I suspect it has alot of truth to it.
If your stock wastegate is 100% open and you are running DP, MP and CB, it doesnt matter what type of boost controller you have you will get boost creep. I suspect people who are not experiencing creep with straight exhaust and stock wastegates are running a more restrictive intake or catback, or it is really really hot where they are, or as previously stated the turboes are not as efficient.
Your options are to port the wastegates to allow them to flow more air that bypasses the turbine, or add restriction to your exhaust flow, either a more restrictive catback exhaust, a hi-flow cat, or restrictor plates.
But I might just be smoking crack and have no idea about what I am talking about.
Mike
If your stock wastegate is 100% open and you are running DP, MP and CB, it doesnt matter what type of boost controller you have you will get boost creep. I suspect people who are not experiencing creep with straight exhaust and stock wastegates are running a more restrictive intake or catback, or it is really really hot where they are, or as previously stated the turboes are not as efficient.
Your options are to port the wastegates to allow them to flow more air that bypasses the turbine, or add restriction to your exhaust flow, either a more restrictive catback exhaust, a hi-flow cat, or restrictor plates.
But I might just be smoking crack and have no idea about what I am talking about.
Mike
12-31-01, 01:33 PM
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Power FC
Wont a Power FC or S-AFC read the spike in boost, and counter it with fuel enrichment? Maybe that is why the guy with the PFC doesnt get any boost creep. Just an idea. I am not 100% sure on the capabilities of the power FC, but I would hope that such an expensive computer wouldbe able to adjust fuel amounts as boost rises.
12-31-01, 01:47 PM
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The more restrictive intake/exhaust will help to control it better. An open intake, mp, and Apexi GT catback I would assume to experience alot of boost creep.
Porting the wastegate is a good idea but if you make to walls to thin, it could crack.
Porting the wastegate is a good idea but if you make to walls to thin, it could crack.
12-31-01, 01:53 PM
#20
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Having a PFC to add fuel with the increasing boost is not addressing the problem. the situation Red95T-Rex describes does not eliminate creep. You might be decreasing the risks associated with poor boost control, but it is a less than ideal situation. You have to assume that if you are getting creep that your wastegates are already 100% open and cannot flow anymore air.
Mike
Mike
12-31-01, 02:06 PM
#24
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I am sure there is a professional who can port your wastegates. There are probably "professionals" who will also do other things for you if you want.
Boost creep is bad because it usually leads to detonation. ==> new motor.
Popoff valves can work as a safety backup, but are not a solution to creep. You will get a manifold pressure that flutters around the point the popoff valve is set at. Some pop off valves are not on or off at the exact boost you set, and some may leak boost. (but that is what I have heard and not experienced).
Boost creep is bad because it usually leads to detonation. ==> new motor.
Popoff valves can work as a safety backup, but are not a solution to creep. You will get a manifold pressure that flutters around the point the popoff valve is set at. Some pop off valves are not on or off at the exact boost you set, and some may leak boost. (but that is what I have heard and not experienced).