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Go Back   NASIOC > NASIOC Technical > Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo)

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Old 10-07-2012, 10:18 PM   #1
11snyderjo
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Default not hitting peak boost anymore?

hey guys i have a 2006 wrx swapped with a vf43 turbo protuned at 19 psi . ive never had problems maxing out my mechanical boost gauge until today. i was showing a friend and i noticed it was peaking at about 16-17 psi. idk where that other 2 psi went? is it because its getting colder??? i have a grimmspeed EBC with it and of course the upgraded exhaust and fuel parts. any help would be greatly appreciated! thanks!
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Old 10-08-2012, 01:12 AM   #2
sc00ter
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It could be as simple as a drop in barometric pressure due to weather/altitude, or an actual issue with the setup.

I know in my case I hit my 19psi target without issue around Denver (5200ft elevation) 90% of the time, but some days it won't get much past 17-18psi depending on the weather. When I head up into the mountains the increase in altitude usually has me peaking around 16psi or 17psi.

If you continue to not hit target boost consistently, I'd say to check all your lines and fittings to make sure everything is sealed properly then try cleaning your MAF and resetting the ECU.

It might sound silly, but that's where I would start.
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Old 10-08-2012, 12:04 PM   #3
11snyderjo
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@sc00ter awesome thanks a lot for your input. I'm in Wyoming which has high elevation so perhaps this weather change effecting my boost is normal. I'm glad you could relate to this issue. Our results are very similar. If anything else I will reset my ecu and try again but your response seems very reasonable. Then ill check my boot and ect.
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Old 10-08-2012, 12:32 PM   #4
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It should be noted that you will see less boost when the temp is warmer but you should see more boost when the temp is colder.
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Old 10-08-2012, 01:10 PM   #5
Steve.804
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Several things can cause you not to hit peak boost. Could be something as simple as a leak in your i/c plumbing or one of the vaccum lines leading to or from your EBC solenoid. Once you rule that out you could be looking at something mechanical such as your wastegate door might be opening prematurely (assuming you're still IWG). If you are EWG it would sound like a horrible exhaust leak all of the time. Because the differnce between peak and actual is so small I'd be willing to guess you have a pressure leak somewhere.
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Old 10-08-2012, 03:36 PM   #6
11snyderjo
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so i eliminated the resetting the ecu part. I got in the interstate after doing so and still peaking at 16psi.. it will hold that boost without tapering off. after work ill try your suggestions Steve. I'll check ebc lines and go from there with i/c plumbing. however is there any way to check or know if the wastegate door is now opening prematurely mayby see if wastgate feels stiff by hand still? Note: still have IWG. thank you guys for your input
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Old 10-08-2012, 04:06 PM   #7
Steve.804
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I'd suspect wastegate if you can't find any leaks. Thing is though, the leak could be so small that it could be really hard to find. If I suspected a vaccum line leak I'd just replace the line(s) to rule it out for sure. NAPA sells it by the foot, probably cost you $2-3.00. Also make sure you use some small zip ties to make it as tight of fit as possible.
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Old 10-08-2012, 06:29 PM   #8
kaczmarz
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Check your wastegate compensation table for intake temperature. Cobb and Perrin play so much on the safe side, as far overboosting in cold weather is concerned, that their maps will provide less boost in winter than during summer. You're protuned, however, so probably your map is locked and you're out of luck adjusting this table by yourself (I've got the same problem). To be able to have access to this particular table to make a simple adjustments is one of the main disadvantage of a protune.
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Old 10-09-2012, 12:49 PM   #9
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You could have a boost leak somewhere or your tuner did not adjust the Turbo Dynamics for colder intake temps. If you are certain you have no boost leaks, check your tune.
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Old 10-09-2012, 10:04 PM   #10
11snyderjo
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Default Problem resolved!

Thanks a bunch you guys for all your input. turns out the problem was one of the small vacuum/ boost lines coming off the EBC. the line was pinch below between my intake bracket. so i cut that piece out of the line and my boost is back to where it should be.thanks Steve for directing me towards my ebc lines.
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