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Old 02-08-2012, 09:58 PM   #1
JohnJW
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Default Boost spike than surge.

So I don't normally post as I usually search or find a way to figure stuff out myself, but I need help on this one.

I've owned my car (2002 WRX Wagon 5mt) for about a 6 weeks now and have worked on it more than I drive it.

Car currently has a Cobb AP, Cobb SF intake, after maf hose, Perrin inlet, Samco charge air hoses, tgv's deleted along with cats deleted.

So my problem is that the boost spikes at first and continues to surge back and forth. Sometimes it happens and sometimes its fine. I've logged boost spikes up to 19.6psi regularly. Today though, I've had enough. Pulling a mild hill I had it in 5th gear and had it at about half throttle. I would consistantly surge from about .5bar to above 1.1 bar. I could make it do it anytime. This will happen in lower gears but happens much quicker. Sometimes it pegs 1.1 bar and stays there till boost taper near redline.

So what I've done to correct this issue is replacement of every pcv hose, vacuum line, boost control solenoid, and vacuum t. I've smoked the intake tract numerous times with no leaks showing. All new oem parts.

When it does happen, I swear I can almost hear the bypass valve venting, or something similar.

It also seams better when I reflash the ecu, but gets worse the longer I go on a fresh tune. My DAM stays around 15-16 and everything else looks good.

I would be so happy if someone can give me a reasonable direction. My next step is to tape my phone to my hood and record my wastegate actuator. lol
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Old 02-08-2012, 11:51 PM   #2
wrxdrvr
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I would put in a 1/8 or slightly less ID in-line connector in the vacuum line between the T from the turbo to the BC solenoid to restrict airflow out of the wastegate...
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Old 02-09-2012, 01:08 AM   #3
JohnJW
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So another thing to add is that the car has done it since I've owned it and along with the mods I have done. From stock to the way it is now. I would like to think that there is a way to fix this with oem part replacement.

I don't agree with modding a control system to fix it. Normal WRX's don't do this, and they don't have a 1/8 inch or smaller wastegate signal line.
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Old 02-09-2012, 01:38 AM   #4
wrxdrvr
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The OEM vac lines from the T to BC solenoid do have that in-line restrictor, I'm guessing it's not there now...
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Old 02-09-2012, 10:22 AM   #5
JohnJW
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No, its there, I purchased a new T with the pill included from Subaru. Also the lines to the bcs have connectors in them to go to a larger hose. The ports on the bcs are larger then the ports on the wastegate actuator and turbo charge side.

Also I've tried the LWG versions of the maps with no success.
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Old 02-09-2012, 11:19 AM   #6
Omega_2nr
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Are you sure your WGate is working properly? Opening/closing properly.....or is there some sort of adjustment on it?
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Old 02-09-2012, 11:25 AM   #7
wrxdrvr
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Quote:
Originally Posted by Omega_2nr View Post
Are you sure your WGate is working properly? Opening/closing properly.....or is there some sort of adjustment on it?
That's the next thing to check, I would give it a turn to slightly loosen the preload...
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Old 02-09-2012, 12:31 PM   #8
moonrider_99
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I would start by removing any tension from your WG and see if you still get a surge.
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Old 02-09-2012, 08:36 PM   #9
JohnJW
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Thanks for the replies so far.

So I might try adjusting the rod. Is this a normal service procedure for older WRX's? I don't understand how the rod would lengthen over time and preload the wastegate? I'm sure the car was not like this to begin with when new.

I just don't want to have a bandaid fix, when the real problem is.......?
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Old 02-09-2012, 09:41 PM   #10
wrxdrvr
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It's not you car from day 1 is it? You don't know what has been done to it. That's why I went with making sure the Vac. lines were the proper lines at first, If they are, then proper adjustment of the preload on the wastegate is next. If adjusting it doesn't fix the problem then you need to put it back to where it was...
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Old 05-22-2012, 08:03 AM   #11
Stirav2
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Be careful with this man, I had/have the same problem. 1-3 gears no problem. 4th sometimes and not so bad, but 5th was pretty bad and only happened within a certain rpm range. One day some dude was tailgating me so I lost him after a curve punching it and lost my 5th gear completely during the surge did you ever get to fix this problem?
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