03 evo 8 wont boost past 20psi ????
Jul 20, 2006, 10:40 AM
#1
03 evo 8 wont boost past 20psi ????
stock turbo with no boost signal still wont boost past 20psi. Turbo looks fine, no shaft play. actuator is connected and has correct preload. Actuator tested, starts to open at 16psi, full open at 20psi.
No boost leaks. Checked pressure by removing filter and using 3" plug for boost checks. New MR BOV, diaphram holds vac and boost. No leak on signal line.
No exhaust leaks of any sort. car boosts quickly feels strong for 20psi, just wont go higher.
Any ideas? The owner purchased the car this way. He was told the stock plastic BOV was leaking. I always say 90% of failures are from people working on it. I dont have a history on the car. Only mods are 3 in turbo back, and custom intake. I do see that the turbine housing is painted silver. The only thing I can think might be wrong is one of the wastegate pucks fell off. Since one is still on, the wastegate preload wouldn't look any different. Very far fetched. I have seen the pucks fall off on DSM but cant image it happening to a car so new.
Next test would be to wire the actuator shut to see if it wont boost higher. Hate to drop the turbo only to find the the pucks are still there. Any ideas would be helpful.
No boost leaks. Checked pressure by removing filter and using 3" plug for boost checks. New MR BOV, diaphram holds vac and boost. No leak on signal line.
No exhaust leaks of any sort. car boosts quickly feels strong for 20psi, just wont go higher.
Any ideas? The owner purchased the car this way. He was told the stock plastic BOV was leaking. I always say 90% of failures are from people working on it. I dont have a history on the car. Only mods are 3 in turbo back, and custom intake. I do see that the turbine housing is painted silver. The only thing I can think might be wrong is one of the wastegate pucks fell off. Since one is still on, the wastegate preload wouldn't look any different. Very far fetched. I have seen the pucks fall off on DSM but cant image it happening to a car so new.
Next test would be to wire the actuator shut to see if it wont boost higher. Hate to drop the turbo only to find the the pucks are still there. Any ideas would be helpful.
Jul 20, 2006, 11:20 AM
#3
FYI - 20 is stock psi
?????
Yes search the plastic DVs can leak.
Custom intake? Explain? What has changed?
Silver turbo housing? Um mine looks silver too - mine must be painted then (sarcasm)...
You need a MBC/EBC if you want more boost - but without a tune you will hit boost cut if you go too high. But hey raise that up to 28psi w/93oct - enjoy your 30secs before meltdown.
Im trying to say (with sarcasm) - search.
?????
Yes search the plastic DVs can leak.
Custom intake? Explain? What has changed?
Silver turbo housing? Um mine looks silver too - mine must be painted then (sarcasm)...
You need a MBC/EBC if you want more boost - but without a tune you will hit boost cut if you go too high. But hey raise that up to 28psi w/93oct - enjoy your 30secs before meltdown.
Im trying to say (with sarcasm) - search.
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Jul 20, 2006, 11:55 AM
#8
HAHA, I was just going to grab this:
https://www.evolutionm.net/forums/sh...ht=boost+taper
But you beat me to the punch
https://www.evolutionm.net/forums/sh...ht=boost+taper
But you beat me to the punch
Jul 20, 2006, 12:51 PM
#9
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No one that posted above me replying to the original poster seems to have any idea what they are talking about. Without a boost signal to the WGA, the turbo should spike to over 30 psi. The fact that it doesn't indicates that there is a problem.
SmikeEvo: If your turbine housing is silver, then it really must be painted. Everyone else's has rusted. Also, you can raise boost without a MBC or EBC by removing the boost signal to the WGA, but it is not safe to do so as the waste gate will not (or should not) open and you will not have any control over your boost.
SmikeEvo: If your turbine housing is silver, then it really must be painted. Everyone else's has rusted. Also, you can raise boost without a MBC or EBC by removing the boost signal to the WGA, but it is not safe to do so as the waste gate will not (or should not) open and you will not have any control over your boost.
Jul 20, 2006, 12:57 PM
#10
Originally Posted by PVD04
No one that posted above me replying to the original poster seems to have any idea what they are talking about. Without a boost signal to the WGA, the turbo should spike to over 30 psi. The fact that it doesn't indicates that there is a problem.
SmikeEvo: If your turbine housing is silver, then it really must be painted. Everyone else's has rusted. Also, you can raise boost without a MBC or EBC by removing the boost signal to the WGA, but it is not safe to do so as the waste gate will not (or should not) open and you will not have any control over your boost.
SmikeEvo: If your turbine housing is silver, then it really must be painted. Everyone else's has rusted. Also, you can raise boost without a MBC or EBC by removing the boost signal to the WGA, but it is not safe to do so as the waste gate will not (or should not) open and you will not have any control over your boost.
Jul 20, 2006, 03:24 PM
#12
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[QUOTE=94AWDcoupe]stock turbo with no boost signal still
QUOTE]
Sorry but I did not understand what you meant by "boost signal" until you clarified in the later post. If you would have said there was no vacuum line connected to the actuator then I would have understood.
Sorry about that.
QUOTE]
Sorry but I did not understand what you meant by "boost signal" until you clarified in the later post. If you would have said there was no vacuum line connected to the actuator then I would have understood.
Sorry about that.
Jul 20, 2006, 05:46 PM
#13
Originally Posted by WOT
are you sure about your boost gauge? have you tried a different boost gauge?
does the car feel weak? does it knock @ peak boost?
does the car feel weak? does it knock @ peak boost?
Jul 20, 2006, 05:50 PM
#14
According to the brochure, a stock
--> 03-04 Evo has boost set at 19.00 Psi @3500 rpms tapering down to 16.24 Psi @6500 rpms
-->05 Evo has boost set at 20.31 Psi @ 3500 rpms tapering down to 17.40 @ 6500 rpms
To conclude, your boost is accurate as long as nothing was modified such as a Manual Boost Controller.
(Don't question my stats because I'm willing to bet more than your net worth that it is correct
)
--> 03-04 Evo has boost set at 19.00 Psi @3500 rpms tapering down to 16.24 Psi @6500 rpms
-->05 Evo has boost set at 20.31 Psi @ 3500 rpms tapering down to 17.40 @ 6500 rpms
To conclude, your boost is accurate as long as nothing was modified such as a Manual Boost Controller.
(Don't question my stats because I'm willing to bet more than your net worth that it is correct
)
Last edited by AJsGenerX; Jul 20, 2006 at 05:59 PM. Reason: Giving the 05' Model Brochure stats
Jul 20, 2006, 06:02 PM
#15
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Originally Posted by Lancerlover
According to the brochure, a stock
--> 03-04 Evo has boost set at 19.00 Psi @3500 rpms tapering down to 16.24 Psi @6500 rpms
-->05 Evo has boost set at 20.31 Psi @ 3500 rpms tapering down to 17.40 @ 6500 rpms
To conclude, your boost is accurate as long as nothing was modified such as a Manual Boost Controller.
(Don't question my stats because I'm willing to bet more than your net worth that it is correct )
--> 03-04 Evo has boost set at 19.00 Psi @3500 rpms tapering down to 16.24 Psi @6500 rpms
-->05 Evo has boost set at 20.31 Psi @ 3500 rpms tapering down to 17.40 @ 6500 rpms
To conclude, your boost is accurate as long as nothing was modified such as a Manual Boost Controller.
(Don't question my stats because I'm willing to bet more than your net worth that it is correct
)Last edited by mike 99gsx; Jul 20, 2006 at 06:22 PM.
