I bought a 2002 wrx a few weeks ago and my boost is higher than it should be. I am a big fan of reliability, so this worries me. I have noticed that there is a T connector in a line that goes to the turbo (waste gate actuator, i think). That's all dandy, but there are only 2 lines connected to the T connector. the line at the bottom of the ' T ' is non existent.
according to the stock boost gage, i have been peaking at about 15psi and tapering down to 14psi at red line in 1st - 3rd gear. 4th is peaking at about 16 and tapering to 15. I have hit fuel cut in 5th gear (17 psi) before i began to pay attention to this type of stuff.
There's not any type of boost controller on there now. the previous owner may have taken it off to sell it, I'm not sure. in your picture, the line that says 'to wastegate solenoid valve' is not there. there is no line connect to that part of the ' T '.
Maybe the ecu has been flashed? Another possibility is that the wastegate has been turned (tightened) a few times to hold the wastegut shut longer. Take a look at the c-clip and if it looks like it's been taken off a few times, then that's probably where your high boost is coming from. If that's the case, just loosen the gate a full turn, and you should be good. Also, another possibility is the 3/16th mod. Pull out the little restrictor on the end of the t-hose thing and find a 3/16" drill bit. Stick the drill bit into the restrictor, and if it fits, then go to autozone and buy a 1/8" restrictor to replace it. You don't want to be running with that restrictor. Last but not least, I hate to be the bearer of bad news, but the oem boost gauge is known to be unaccurate. Most people don't trust it. Your gauge COULD be wrong, but most likely your problem lies in what I have previously mentioned.
What do you know about the car's history? Do you know the previous owner? Has it been modded? Knowing the answers to these kinds of questions will really help you discern just how reliable your car is right now. Hope this helps.
Oh, I just read your last post and if the wastegate to solenoid valve is missing, then that's probably your problem. Weird thing is, I think that you should be running LOW, not HIGH, so I really think there must be an mbc somewhere...
I'm not sure if the ecu has been flashed or not, although I have reset it once. I don't know the previous owner, but everything is very clean, it runs great and i got a pretty good deal on it. It does have a perrin rear sway bar and rear end links. I think that is all...at least i haven't found anything else yet. Anyway, when I get home from work I will check the things that you mentioned. I am aware that the stock boost gage is not accurate, that's why I mentioned that it was the stock boost gage that I was getting my numbers from. Anyway, the car has 57,000 miles on it now so hopefully it will last, I'm starting to get worried though.
Thanks for your help. I'll post back once i have a chance to check things out and look for a mbc.
Well, it's a wierd setup i have here that is best explained by a picture. No mbc, but a few disconnected vacuum hoses. Notice the ' T ' is missing one vacuum hose and the black coupler is missing the second side to it. I can't understand how this would work to increase the boost. Thanks for your help.
From the turbo to the wastegate actuator, the line has a T fitting in it with one end of the T open to the atmosphere. you can see it in the picture that I attached.
Eliminate that "T".. Route a solid unencumbered line from the Barb fitting on the Intake Housing to the Wastegate Actuator. What is happening now is that that open end of that line is allowing pressure to escape and thus preventing the Wastegate actuator from opening the wastegate.. How it works is this.. The pressure from the compressed air pushes on a diaphragm inside the actuator which pushes the rod and opens the wastegate to prevent over-boosting and to bypass the Exhaust turbine when there is no need for boost.. With that line open to the atmosphere there is no pressure build up to operate the Wastegate Properly.. Route a solid line and you should boost stock levels..
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02 WRX.. Tearing up the streets Yet again.. "Hells Yea"..
sweet man. Thanks. But, what about the other disconnected vacuum hose, the black one with the black coupler attached to it? In the picture it's sitting just to the right of the wastegate actuator. it goes to something attached to the Front passanger side shock tower then a tube goes to the intake. You've been a great help!
Edit: Am I just missing a length of hose between the T fitting and the black fitting?
Well I got it fixed. I put a length of hose between the two open fittings. The boost is just like stock now (slower than it was before, haha). Thanks the help everyone, now time to make power the right way. How much did this length of time running at the higher boost levels hurt my engine?
From looking at that pic, there was a mbc (or similar form of boost control) on there at one point. The hose coming from the factory BCS needs to be hooked up to the "T" that's left open.
From looking at that pic, there was a mbc (or similar form of boost control) on there at one point. The hose coming from the factory BCS needs to be hooked up to the "T" that's left open.
Exactly what I did. . It worked perfectly, good call!
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. It worked perfectly, good call!
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