Boost issue/loss twin turbo c5z
#1
Boost issue/loss twin turbo c5z
Hi guys. My tt z06 is down about 5psi on all 6 settings on my eboost2. Car sat for almost a year, have never had boost issues before, but now my sp1 setting is seeing 12.6-12.8 psi instead of 17.6 like normal. Car seems to run and drive around fine but is def down on power. Air filters were dirty, cleaned and made no diff at all. Looked for vac leaks, havnt found anything. Any ideas? Setup is hke 347 with custom twin setup 6265s, pumpgas/meth, tial 50mm bov's, 38 mm wastegates, air to air intercooler. Thanks in advance
#4
#6
Le Mans Master
also check for vac hose leaks and the boost controller sound's like you are running the boost pressure that the waste gate spring is set for and the boost controller "isn't"
#8
Advanced
#10
Melting Slicks
Then test it.
Any leaks on the line to the gates, would increase boost.
How/where are you reading boost ? Just on the EBoost or is this low reading confirmed elsewhere ?
Do both readings match, or are they different ?
Is whatever blow off valve ( if fitted ) working correctly ?
Any leaks on the line to the gates, would increase boost.
How/where are you reading boost ? Just on the EBoost or is this low reading confirmed elsewhere ?
Do both readings match, or are they different ?
Is whatever blow off valve ( if fitted ) working correctly ?
#12
Update
Pulled gates off and checked, they open at 15psi like they should, put all
back together, zip tied all
connections, took out for test drive, same thing, boosts up to 12psi then falls back to 10psi. Have checked , gates, bov’s, bcs is switching, turned controller off, made no difference. Really at a loss. I can turn boost up, it will go higher but falls off still and still will not see target boost as it did before. It is 5-8psi off on every setting.
back together, zip tied all
connections, took out for test drive, same thing, boosts up to 12psi then falls back to 10psi. Have checked , gates, bov’s, bcs is switching, turned controller off, made no difference. Really at a loss. I can turn boost up, it will go higher but falls off still and still will not see target boost as it did before. It is 5-8psi off on every setting.
#14
What kind of connections/fittings do you have on your vacuum line connections? My setup uses those push-to-lock style connections. You might have an issue there and not necessarily a hole in one of the hoses?
I assume you have one compressor side fitting capped off while the other goes to the boost controller solenoid? Maybe there is an issue with that line?
Could also be an issue with the boost controller itself; maybe the solenoid is acting up?
Also worth it to test that BOV and make sure its working properly. Only way I know to do that is take it off, push it open and hold your finger on the fitting/cap the fitting and make sure it doesn't close. At least rule that out.
I assume you have one compressor side fitting capped off while the other goes to the boost controller solenoid? Maybe there is an issue with that line?
Could also be an issue with the boost controller itself; maybe the solenoid is acting up?
Also worth it to test that BOV and make sure its working properly. Only way I know to do that is take it off, push it open and hold your finger on the fitting/cap the fitting and make sure it doesn't close. At least rule that out.
#16
#17
Melting Slicks
Stick a boost gauge onto the line going to the BOV and check this in real world operation on the road. Just in case there is an issue there with it not receiving a suitable signal, maybe a blockage, leak etc.
And the w/g test I asked was with no lines going to the gates. This should yield maximum, potentially uncontrollable boost, hence proceed with caution.
But if this does not happen and you're still boost limited...there is a major problem, but clearly not gate related as they should be fully shut.
And the w/g test I asked was with no lines going to the gates. This should yield maximum, potentially uncontrollable boost, hence proceed with caution.
But if this does not happen and you're still boost limited...there is a major problem, but clearly not gate related as they should be fully shut.
#18
Test
Will do thank u!
Stick a boost gauge onto the line going to the BOV and check this in real world operation on the road. Just in case there is an issue there with it not receiving a suitable signal, maybe a blockage, leak etc.
And the w/g test I asked was with no lines going to the gates. This should yield maximum, potentially uncontrollable boost, hence proceed with caution.
But if this does not happen and you're still boost limited...there is a major problem, but clearly not gate related as they should be fully shut.
And the w/g test I asked was with no lines going to the gates. This should yield maximum, potentially uncontrollable boost, hence proceed with caution.
But if this does not happen and you're still boost limited...there is a major problem, but clearly not gate related as they should be fully shut.
#19
Update
Did boost leak test, found a weld leaking on one of the charge pipes. Car is currently at shop getting fixed, will update again when i pick it up, thank u to all that helped me!