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-   -   7lbs of boost WOT, where to start looking? (

adammc92 10-01-2012 02:57 PM

7lbs of boost WOT, where to start looking?
so i picked up a higher milage spec-b. i added a spt intake and just last week a prosport boost gauge really only for moitoring the motor. once i poped it on it was only hitting 6-7lbs of boost. my first thought was maybe they tuned it down for the legacy's. also that was why the car felt so slow. after homework the spec-b's should be around 13-14lbs. so im loosing a good bit somewhere.

I was gonna start looking for vacuum leaks but playing on youtube it seems like most people will hear a clear loss of boost and the needle will show it. On mine it struggles to 6-7 and stays there and no real noticable noise ither. it wont hit full boost untill about 3-4k

I was gonna have a compression check on the motor to see if im getting blow by but wanted your guys ideas on what to start at.

dingbang 10-01-2012 03:18 PM

Previous mods done? 7psi consistently sounds like WG only pressure....boost control solenoid working? If prev owner did a back to stock before selling and switched from a 3port ebcs to the stocker...restrictor pill put back in place?

.... 10-01-2012 03:50 PM

check every vacuum line and make sure they are tight, dont forget the one under the intercooler, its hard to see kinda. Make sure the tabs on your intercooler are all intact, BPV is connected properly, Check the bolts from turbo to intercooler, If none of this fixes your problem, idk what to tell you. But thats usually the first place I'd look.

EJ25subie05 10-01-2012 04:31 PM

^2 that post covers everything you need to look for. do a boost leak test. cost me under $10 to make one. you will be able to find the leak much easier this way, most common are the intercooler end caps blowing off (happened to me and was running off WG pressure only), and the vacuum lines under the IC. good luck

adammc92 10-01-2012 05:13 PM

great helpfull replys fellas, I came from vortex and nothing but hate from that site.

From the best i could tell there were no mods, though the bolts on the factory bpv looked they had be removed witch makes think the PO had an aftermarket one. but the PO did more audio upgrades and no perfomance.

I plan doing a home vac test this weekend when i can get home. Im stationed in VA and home (pa) is where all my tools and shop acceses is.

I read that the boost solienod acts up, something i was gonna look in to also. i just wanted to get a better direction before i start digging. Ive read that the end tanks do leak that was one of the areas i was gonna look for when i leak test it.

I know how to turn a wrench and knew a ggood bit about these cars but i need do some more homework. esp on this issue. Thanks for your help, any one else please chime in, ill be sure to update if/when i find my issue.

EJ25subie05 10-01-2012 06:17 PM

where in Va are you located?

adammc92 10-01-2012 06:53 PM

Hampton/Newport news. I'm hoping to find a mature subaru group around here. I was in the VW scene pretty good till my GLI got flooded but most the "kids" in that culture are more trouble than what's it's worth.

cryo 10-01-2012 07:00 PM

See if you can find someone local to you that can pull a learning view. That will initially tell you a few things. it will let you know if the ecu has reduced boost to wg pressure because of knock and lowered iam or if you have a gross post turbo leak causing the lack of boost. Otger than that just check everywhere for leaks but it sounds like wg pressure to me as well.


iNVAR 10-01-2012 07:03 PM

1) Get a tactrix or vagcom cable and laptop/netbook to conncet to
2) Connect it and immediately pull a Learning View (search) and post it here
3) stop romping on it until you figure out what's wrong

It is LIKELY that the reason you are running wastegate only pressure is because your ECU has pulled timing for one reason or another by reducing IAM (Ignition Advance Multiplier, which pulls timing everywhere).

EJ25subie05 10-01-2012 07:50 PM


Originally Posted by adammc92 (Post 4095548)
Hampton/Newport news. I'm hoping to find a mature subaru group around here. I was in the VW scene pretty good till my GLI got flooded but most the "kids" in that culture are more trouble than what's it's worth.

i thought maybe you were local and you could use my tools and what not. but your just too far, should be some nice local guys over that a ways.

.... 10-01-2012 08:16 PM

Does it struggle to build boost in lower gears but as you get moving and upshift build more boost?

adammc92 10-02-2012 03:57 AM

I'm not driving like I stole it since I've seen the present boost. I know when something like that isn't right to take it easy. Well first gear is short where when I'd be shifting at about a grand from redline it would slowly just hit 6-7. 2-3 same thing slow creep to 6-7 but will peak and stay there more than first. I'll see what I can dig up for a vag cable. We used them a lot in the VW's ill see if I can source one

ripemeat 10-02-2012 06:26 AM

get rid of that horrific intake.

adammc92 10-02-2012 09:32 AM


Originally Posted by ripemeat (Post 4096075)
get rid of that horrific intake.

I got a great deal through a dealership on it. Unless your recomending a different one i have an extended warrenty on it and chose the spt v/s others on the concept that if something happens to the motor id have less of a chance by a dealership saying oh its cuz you bought XX intake.

I havent had a chance yet to test anything but i looked during lunch and the cold side of the intercooler where it kicks off to the TB, looks really oily and the boot doesnt look like its snuged up too well. So untill i can get the time to test the system im gonna snug that up and see if it helps.

FJuan 10-02-2012 09:37 AM

Put back the stock air box, reset the ecu, and see if it goes into limp mode again. If the car is not tuned for the aftermarket intake, it could cause some issue.

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