Low Boost Problem

Hello Guys,
after installing a turbo on my stock k20a2 I can't hold the boost low enough.
For the first I had installed a 0,6bar spring in my wg but the boost went up to 1bar/15psi in the boostcut at 7100rpm...
Now I've the smallest 0,2bar/3psi spring in it and the boost goes still up to 11psi at 8100rpm.

My dumptube is welded into the downpipe could this be the problem that I can't go lower?

I've seen other turbobuilds with bigger turbos and 8 9psi.

Sorry for my bad english, but I'm from Germany.

Are you sure your vacuum lines to the wastegate are correct and not backwards? Had a buddy do that and it would spike boost super quick lol

Also no vacuum leaks etc.

How could it be backwoards?
I've a "Y" connector at the end of my intake manifold with one line which goes to bov an the other to the wg (44MVR). The one at the wg is installed at side, other sideports are closed and the upper for boostsolenoid are open.

check and see if the solenoid is hooked up this way.

http://www.d-series.org/forums/attac...ateinstall.jpg

I've no solenoid, boost is only regulated by wg spring.

so no solenoid and no controller. that explains everything

what turbo manifold do u have?

AFI sidewinder and GTX 3076

might be experiencing boost creep

Quote:

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Originally Posted by monjarassi

so no solenoid and no controller. that explains everything

what turbo manifold do u have?

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That doesn't explain anything. If he has a boost/vac source hooked up to the bottom gate that's all that is needed for the wastegate to function properly at spring pressure. Just make sure the top port on the wastegate can vent to the atmosphere.

Quote:

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Originally Posted by stigrl06

might be experiencing boost creep

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Yea I think this a typical case of boost creep. What size is the wastegate? Picture of the manifold and wastegate neck?

the OP never specified what all he had or has done to the gate so it explains everything.

Quote:

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Originally Posted by monjarassi

the OP never specified what all he had or has done to the gate so it explains everything.

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Explains why he has boost creep problems? Or just explains how it's setup? Based on what he's said he either has a leak in the line going to the bottom port of the wastegate, a leak in the diaphragm of the wastegate, or a poorly designed manifold that is simply creeping.

Wastegate is a 44mm MVR.
Now I've welded my dumptube that it's open because I thought there could be too much backpressure between downpipe and wastegate but still boost creep. After that I made a port in the compressor housing for my wg with a shorter line but still boost creep.

Here's a pic of my manifold. I know the position of the wg neck is not the best...
[IMG]http://imagizer.imageshack.us/v2/280...746/aab765.jpg[/IMG]

That's why you're boost creeping. Manifold design is the most common cause for boost creep.

i have same manifold no creep im on 8 psi also gt3071
https://scontent-a-dfw.xx.fbcdn.net/...67720057_n.jpg

Hmm, which wastegate and spring do you have installed.

Quote:

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Originally Posted by Brezno

How could it be backwoards?
I've a "Y" connector at the end of my intake manifold with one line which goes to bov an the other to the wg (44MVR). The one at the wg is installed at side, other sideports are closed and the upper for boostsolenoid are open.

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As a start, you should never Tee your wastegate and BOV. They should have their own vacuum sources.

Quote:

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Originally Posted by monjarassi

check and see if the solenoid is hooked up this way.

http://www.d-series.org/forums/attac...ateinstall.jpg

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Follow this diagram when you have a boost controller

Quote:

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Originally Posted by Brezno

Wastegate is a 44mm MVR.
Now I've welded my dumptube that it's open because I thought there could be too much backpressure between downpipe and wastegate but still boost creep. After that I made a port in the compressor housing for my wg with a shorter line but still boost creep.

Here's a pic of my manifold. I know the position of the wg neck is not the best...
[IMG]http://imagizer.imageshack.us/v2/280...746/aab765.jpg[/IMG]

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Definitely a creep-able manifold. Seems that this isn't the issue though. Just because it looks like it can creep doesn't mean that's why. Ensure that the vac line isn't kinked and is big enough and strong enough. There are many cases where poor vacuum lines end up collapsing, typically when things are hot. Also, as a rule of thumb, make sure to zip-tie your vacuum line connections. Slip-fit barb fittings alone don't cut it.

Quote:

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Originally Posted by Brezno

Hmm, which wastegate and spring do you have installed.

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7 psi spring, i have turbosmart 45mm

Another thing to note, just because one setup doesn't creep for someone, doesn't mean it won't creep for someone else.

I've tested without any wg spring today. The result 12psi boostcut at 7800 rpm in 5th.
After checking the mapsensor I've seen some oxidized pins.

http://img.tapatalk.com/d/14/07/24/ura9ygat.jpg

Changed the pins but still creeping...
After installing a second 44mm wg the problem was solved. Now i hold the boost until limiter.
http://img.tapatalk.com/d/14/10/18/8unubu7a.jpghttp://img.tapatalk.com/d/14/10/18/hejemeja.jpghttp://img.tapatalk.com/d/14/10/18/e8aqudup.jpghttp://img.tapatalk.com/d/14/10/18/upa4esa9.jpg

Nice! Did you do the fabrication yourself? [MENTION=888]Brezno[/MENTION]

Yes i did it myself.

Quote:

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Originally Posted by aLmk

Explains why he has boost creep problems? Or just explains how it's setup? Based on what he's said he either has a leak in the line going to the bottom port of the wastegate, a leak in the diaphragm of the wastegate, or a poorly designed manifold that is simply creeping.

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:yeahthat:

Quote:

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Originally Posted by Brezno

Changed the pins but still creeping...
After installing a second 44mm wg the problem was solved. Now i hold the boost until limiter.
http://img.tapatalk.com/d/14/10/18/8unubu7a.jpghttp://img.tapatalk.com/d/14/10/18/hejemeja.jpghttp://img.tapatalk.com/d/14/10/18/e8aqudup.jpghttp://img.tapatalk.com/d/14/10/18/upa4esa9.jpg

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:thumb:

Holy shit that's brave!

Quote:

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Originally Posted by Brezno

Yes i did it myself.

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How is she holding up?