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boost creep is killing my motor

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Old 04-04-09, 04:34 PM
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Thumbs down boost creep is killing my motor

Well today i saw a vacume at 900rpms of 12psi, i am thinking my motor is on its way out. I have been battling boost creep like crazy, i have even put on my stock midpipe and am still getting boost creep in the secoundary to 14psi. I thought my pettit ecu would componsate up to that psi but i guess not. The only thing i can think of is my secoundary waste gate acctuator is not working properly.

So do you think my motor is skrewed?
Old 04-04-09, 05:11 PM
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not screwed, but you should run a compression test and diagnose the turbos using the FAQ section. I don't "think" the petit ecu is "supposed" to prevent boost creep if that's what your getting. I would search more on the petit ecu and find what it's upper limit is for maintaining proper fuel ratio with boost, I think it's somewhere around 12, but I could be wrong.

At the very least, you could always take the dive to pull the turbos and port the wastegate, many threads on that.

What is your boost pattern anyway? Try a different boost gauge too. I did and noticed a difference up to +- 2 psi in varying conditions.
Old 04-04-09, 05:20 PM
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No ECU can control creep on these cars.

What's a 'stock midpipe'?
Old 04-04-09, 05:32 PM
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I wasnt saying my ecu was controlling creep i was saying that my waste gate wont control the secoundary it keeps spiking. I have ported my waste gate also, you only port the first turbos waste gate i didnt think that controlled the secoundary as well??

The boost patern is 10 7 12 13 14psi, i have checked all my lines and connections. As for the boost gauge it has been right on the money before perfect 10 8 10.

By stock mid pipe i mean the center section with the cat in it.

I did all my reserch and everything right urg this is pissing me off
Old 04-04-09, 05:39 PM
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Are you running the stock pills for a boost controller setup? I would look at getting an electronic unit like the HKS or Profec B.
Old 04-04-09, 05:43 PM
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I am not running the stock pills i thought yu were suposto get rid of them. Why an electronic boost controler?
Old 04-04-09, 05:46 PM
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I heard those units are capable of holding boost better.

Here is a link to a boost setup I thought looked good, running on stock ecu I think holding 10 lbs steady:

https://www.rx7club.com/showthread.p...+boost+control
Old 04-04-09, 05:53 PM
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I am running damions setup, It must be my waste gate actuator. I am running my boost controler wide open so that should give me 7psi but it isnt even coming close.
Old 04-04-09, 06:04 PM
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seems your getting close. I'm not sure what else to suggest... just don't use a heavy foot till you get someone to help you look at it.
Old 04-04-09, 06:22 PM
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It has to be the secoundary waste gate not opening i am going to take off the inspection door and take a look and try to move it manualy. My car also started making a wierd sound at idle like a little not poping but little poof sounds i dont know how elst to discribe it.
Old 04-04-09, 06:58 PM
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My secoundary waste gate actuator was completely sezed up what the fu that would be the source of my problems great that may have also cost me a motor in turn

Last edited by GoodfellaFD3S; 04-06-09 at 09:12 AM.
Old 04-04-09, 07:19 PM
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Correction my waste gate was not siezed but had oil in it i am going to do some searches and see what i come up with. My turbos shaft play is very minimal and i dont see oil coming from anywhere wierd.
Old 04-04-09, 08:17 PM
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Originally Posted by yourmom23
My secoundary waste gate actuator was completely sezed up what the fu that would be the source of my problems great that may have also cost me a motor in turn
I`m not sure what you mean by secondary wastegate. There is really only one wastegate proper in this car. There is a precontrol actuator and flapper that controls transition (and primary boost to some degree) but if it seized shut you would get a low transition (because of lack of secondary prespool) but you would not get uncontrolled secondary boost.

Last edited by GoodfellaFD3S; 04-06-09 at 09:12 AM.
Old 04-04-09, 09:05 PM
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I am confused then because there are two actuators and two boost controlers hooked to both so my understanding is you can tune in your boost levels one controler for the first turbo and one for the secound?
Old 04-04-09, 09:17 PM
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No. you need to do some searches. There is one wastegate actuator/flapper. The precontrol flapper is not really a proper wastegate, and after transition it is supposed to always be fully open. The precontrol does not controlling your peak boost level after transition.
Old 04-04-09, 09:59 PM
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Hmm I am wondering, i think my alternater is going out, cuz all my lights come on when i hit above 5k. I am wondering maybe this could be causeing voltage drops making some of my wierd issues. My boost pattern seems to be quite random sometims. Thanks for the search key words, ive been looking and looking and couldnt find any good info about the actuation of the secoundary.
Old 04-04-09, 10:12 PM
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I think i might pull my turbos again and port the waste gate bigger, and put a larger flap on should be worth it my new alt doesnt get here till next week anyway
Old 04-05-09, 06:41 PM
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can you put a larger flap on the stock twins? i think that would be rather hard. I would just enlarge it as much as you could with the original flap.
Old 04-05-09, 06:53 PM
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Originally Posted by RotorRyan
can you put a larger flap on the stock twins? i think that would be rather hard. I would just enlarge it as much as you could with the original flap.
Yes, you can put in a larger door. A lot of non-seq people use the pre-control door as it's a little larger than the wastegate.
Old 04-05-09, 07:58 PM
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Originally Posted by Mahjik
Yes, you can put in a larger door. A lot of non-seq people use the pre-control door as it's a little larger than the wastegate.
Wow thats cool thats a big door, mybe i can buy one off someone in the classifieds for cheap, i was just going to make one. Seems like it might have clearence issues guess not though.

Last edited by GoodfellaFD3S; 04-06-09 at 09:14 AM.
Old 04-05-09, 11:35 PM
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Originally Posted by Mahjik
Yes, you can put in a larger door. A lot of non-seq people use the pre-control door as it's a little larger than the wastegate.
interesting, i was looking for a way to enlarge it more, never thought of the pre-control flapper. Thx for the help!
Old 04-06-09, 12:24 AM
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Give me a call tomorrow and let me know what you need, I have about 10 sets of used turbos laying around and I will practically give you the parts you need.
Old 04-06-09, 12:31 AM
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you shouldnt be creeping with the stock midpipe (cat) or even a high flow cat. I would def check your vaccum hoses and such before looking into porting wastegates. I have a 3inch midpipe with a 2.75 restrictor plate and get no creep.
Old 04-06-09, 01:16 AM
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Try removing the vacuum line that connects to the side of the waste gate actuator(the one coming from the turbo control solenoid) and installing a vacuum cap on it. That should help keep the boost down after transition
Old 04-06-09, 11:21 AM
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Originally Posted by yourmom23
Well today i saw a vacume at 900rpms of 12psi, i am thinking my motor is on its way out. I have been battling boost creep like crazy, i have even put on my stock midpipe and am still getting boost creep in the secoundary to 14psi. I thought my pettit ecu would componsate up to that psi but i guess not. The only thing i can think of is my secoundary waste gate acctuator is not working properly.

So do you think my motor is skrewed?
I agree with DJSeven. If you re-read Damian's thread he ends up capping the extra nipple on each actuator. You will need to reset your controller adjustments (start wide open).

Make sure you don't use a parts-store vacuum cap, it will split and cause bigger problems - get a good one or use a short section of hose and plug the hose.

David


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