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Old 06-15-2013, 11:16 AM   #1
Gs WRX
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Default 17.5 psi WG spring too much?

Yesterday I got pro tuned on my 07WRX after I had installed all the bits and pieces myself (15 hours labor of love). Got 313 ft-lbs at 3960 RPM (331 HP at red line) (17.5 psi boost at 3700 RPM) (91 CA gas) using zero WG duty cycle all the way up to about 5000 rpm where we added 20% DC to keep it from tapering off (tuners goal was for a high boost of 18 psi).

Blouch, 8cm, TD05H-18GXTR, billet with Garrett ball bearing
PW TMIC
Walbro FP 255
ID 1000 cc
Cobb catted DP
Greddy Spectrum Elite CBE

Is it dangerous to have such a high spring setting? What would be a typical spring set for a tuners goal of 18 psi?

He tried lowering the arm adjustment to around 15psi but it was causing a partially open WG and poor spool up. I don't know why Blouch provided a 18 psi WGA for a turbo that was specifically set up for the Subi.

Is it true that you need to "tighten" a lower spring actuator to achieve the desired set vs "loosening" a stiff spring? I am thinking maybe the correct WGA would have a stiff spring to keep a nice seat on the WG valve while having a larger actuator area (in^2) so that a lower psi would overcome the stiff spring.

To be fare, I was given the option to tune it or keep driving on my limp map until we contact Blouch to see what our options are.

So far the new power is simply incredible but I really have barely driven it around nor have I taken any partial throttle data logs to see what kind of boost I get under partial throttle.

Please let me know if this is bad as I don't want to damage my daily driver.
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Old 06-15-2013, 01:07 PM   #2
pmugabi
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If the tuner is happy with the map and there's no knock, there's no need to be worried. Keep the spring as is.
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Old 06-15-2013, 03:56 PM   #3
Gs WRX
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It seems like this setup pretty much makes the electric WG controller obsolete. This is too rudimentary so it just can't be correct. Any other advise?
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Old 06-15-2013, 07:34 PM   #4
cowboy_Rob
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No harm to the high spring pressure it just means that's the lowest you can go. Is it possible the waste gate actuator got dented and is compressing the spring a bit? Or the spring may not be seated in the actuator correctly. Or a leak on the vacuum hose going to the wastegate. Either way as long as it stays at 18 psi where you want it I would run it. Just pay attention to the boost gauge and maybe have your tuner set the over boost limit at 20 so if something does change it can't over post enough to damage anything
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Old 06-15-2013, 08:55 PM   #5
HinshawWRX
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If you're worried then call the tuner. If the tuner is worth a damn, you have nothing to worry about.
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Old 06-16-2013, 09:03 AM   #6
cowboy_Rob
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Quote:
Originally Posted by HinshawWRX View Post
If you're worried then call the tuner. If the tuner is worth a damn, you have nothing to worry about.
I don't get you people. It's his damn car and he wants a second opinion either help him or clam up. I'm sure he already knows he could ask his tuner but really your in the tech section of a huge car community half the responses shouldn't be "go ask your tuner"
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Old 06-16-2013, 09:27 AM   #7
Groundup
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There's far too many variables that we can't tell over the Internet to give advice that someone can count on to work. That's why we suggest asking the tuner. They know way more about that car than we do from listening to the owner.
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Old 06-16-2013, 09:28 AM   #8
STiScooby213
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And tuners are human after all, mistakes can be made. That is all.
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Old 06-16-2013, 09:55 AM   #9
cowboy_Rob
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Quote:
Originally Posted by Groundup View Post
There's far too many variables that we can't tell over the Internet to give advice that someone can count on to work. That's why we suggest asking the tuner. They know way more about that car than we do from listening to the owner.
In some cases sure but this is a really basic problem and really basic to test.
Plus he clearly already talked to his tuner about it since they decided to just tune it at 18. Maybe it's just me since I am my own tuner and work at a shop and know what's going on but nothing pisses me off more then when I'm looking for specifics about something and have to read through pages and pages of stupid responses from people that either didn't read the info posted or just repeat to ask your tuner over and over.

If its a new turbo id call blouch and see if you can get a replacement wastegate actuator sent or ask them what spec actuator it should come with. Otherwise check for leaks in the wastegate hoses or any external damage to the actuator but I wouldn't be worried to drive it. Just keep an eye on the boost level in case it changes
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Old 06-16-2013, 11:00 AM   #10
the suicidal eggroll
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Nothing wrong with running a strong wastegate spring and low (or zero) WGDC. It just means you'll have to control partial throttle boost with the throttle plate instead of the BCS. On a large turbo this isn't a problem, but it can be a little "jumpy" on something like a TD04. I think you'd be fine with an 18g. Either way, it's just a partial throttle driveability issue, once you're at WOT it doesn't matter anyway.
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