Quick Wastegate question
07-13-2013, 10:51 AM
#1
Quick Wastegate question New to turbo's, but is the wategate suppose to be open at idle? I would think it should be closed until you reach the spring pressure of the wastegate then it starts to open?
Right now I have a vacuum line hooked to the side and the top port open to atmosphere. I'm not sure if it has been always open at idle, as I just noticed it now that i have exhaust and a muffler on it. I couldn't hear it before.
Right now I have a vacuum line hooked to the side and the top port open to atmosphere. I'm not sure if it has been always open at idle, as I just noticed it now that i have exhaust and a muffler on it. I couldn't hear it before.
Last edited by gpr; 07-13-2013 at 11:04 AM.
07-13-2013, 11:42 AM
#3
so the waste gate needs pressure at all time? cause the vacuum source I'm using is into the intake after the throttle body.
I'm guessing that side port with vacuum is pulling the gate open?
To make sure i have this hooked up right. The top port vents to atmosphere and the side port should go to compressor housing?
I'm guessing that side port with vacuum is pulling the gate open?
To make sure i have this hooked up right. The top port vents to atmosphere and the side port should go to compressor housing?
07-13-2013, 10:08 PM
#5
TECH Fanatic
I have my jgs hooked to port behind tb. Never pulled it open. Even with the weakest spring it still never did. I have bottom port on side to the port on intake where pcv use to go and top port goes to my hallman boost controller. Now I did have to stifin the springs in the bov because it was pulling open on idle. Just added a spring it stays shut good now until rpm is up then you let off gas.
07-15-2013, 02:24 AM
#6
I will have to get a fitting to hook the wastegate to the compressor housing. As a test I pulled the vacuum line off of the wastegate so it had no vacuum at all and it was still open at idle. That doesn't seem right as I would think with no vacuum to the side of the wastegate, it should be closed at idle?
I also happen to notice the bov was also open at idle, which also seems weird since there is no boost at idle. I also have it coming from the same vacuum line from the intake behind the throttle body. Is this correct for the BOV as well? Or should I run it off the compressor housing as well?
I also happen to notice the bov was also open at idle, which also seems weird since there is no boost at idle. I also have it coming from the same vacuum line from the intake behind the throttle body. Is this correct for the BOV as well? Or should I run it off the compressor housing as well?
07-17-2013, 03:37 PM
#7
^^ their is something wrong with your wastegate. Spring pressure should keep it closed without anything connected. Vacuum on the bottom port also will not pull it open. Only thing vacuum on the bottom port will do is pull it closed when the engine is producing vacuum and possibly damage the diaphragm in the wastegate.
Get a new gate or find out why yours is stuck open, hook the bottom port to any boost source before the throttle body(compressor housing or nipple on any charge pipe) and leave the top port open. Top port is to increase boost with a boost controller.
Get a new gate or find out why yours is stuck open, hook the bottom port to any boost source before the throttle body(compressor housing or nipple on any charge pipe) and leave the top port open. Top port is to increase boost with a boost controller.
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07-17-2013, 03:39 PM
#8
BOV could possibly be open at idle depending on the installed spring rate. This is not a problem if it doesn't leak in boost. Get a stiffer spring if it bothers you but too stiff and it will not open enough or at all to relieve pressure.
Mine does the same thing but has held 20+ psi with a boost leak tester.
Mine does the same thing but has held 20+ psi with a boost leak tester.
07-17-2013, 03:41 PM
#9
I will have to get a fitting to hook the wastegate to the compressor housing. As a test I pulled the vacuum line off of the wastegate so it had no vacuum at all and it was still open at idle. That doesn't seem right as I would think with no vacuum to the side of the wastegate, it should be closed at idle?
I also happen to notice the bov was also open at idle, which also seems weird since there is no boost at idle. I also have it coming from the same vacuum line from the intake behind the throttle body. Is this correct for the BOV as well? Or should I run it off the compressor housing as well?
I also happen to notice the bov was also open at idle, which also seems weird since there is no boost at idle. I also have it coming from the same vacuum line from the intake behind the throttle body. Is this correct for the BOV as well? Or should I run it off the compressor housing as well?
The wastegate should go to a boost only source, ie the turbo compressor housing or anywhere before the TB. Some people use a boost/vacuum source but it's not necessary and sometimes not recommended by the wastegate maker.
Last edited by Ferocity02; 07-17-2013 at 04:04 PM.
07-18-2013, 11:18 AM
#10
the wastegate and bov are from on3, which I'm pretty sure is just a relabeled one from someone else (emusa maybe???)
I called and talked to them and they said it was normal for their wastegates to be open at idle then if you crack the throttle slightly it will close. I haven't had time to even try this or rerouting the line to the compressor. That seems very odd to me to be open at idle and then magically close when i crack the throttle.
Also asked them and they said it doesn't matter if i pull from the intake or the compressor, but i want to try using the compressor housing for the wastegate and see if it makes a difference.
I don't like the wastegate being open at idle because it is annoying and sounds like an exhaust leak. Plus it has to be hurting spool time bleeding off exhaust like that.
I called and talked to them and they said it was normal for their wastegates to be open at idle then if you crack the throttle slightly it will close. I haven't had time to even try this or rerouting the line to the compressor. That seems very odd to me to be open at idle and then magically close when i crack the throttle.
Also asked them and they said it doesn't matter if i pull from the intake or the compressor, but i want to try using the compressor housing for the wastegate and see if it makes a difference.
I don't like the wastegate being open at idle because it is annoying and sounds like an exhaust leak. Plus it has to be hurting spool time bleeding off exhaust like that.
07-18-2013, 11:22 AM
#11
The BOV needs to go to a boost/vacuum source, ie the intake manifold behind the TB. Vacuum opens it up when off the throttle/decel, and boost plus the spring holds it shut in boost. I used a heavy spring so it was closed as idle, I didn't want it sucking in air through the BOV. I trimmed the spring a little bit so it opens up at vacuum slightly more than idle vacuum.
The wastegate should go to a boost only source, ie the turbo compressor housing or anywhere before the TB. Some people use a boost/vacuum source but it's not necessary and sometimes not recommended by the wastegate maker.
The wastegate should go to a boost only source, ie the turbo compressor housing or anywhere before the TB. Some people use a boost/vacuum source but it's not necessary and sometimes not recommended by the wastegate maker.
Does it hurt anything to have both the bov and wastegate coming from the compressor housing? I'd assume both would still work properly.
07-18-2013, 11:24 AM
#12
Actually after thinking about it i see why putting the bov to the intake/vacuum works better. If the bov spring is 8psi and you are only building 2psi and let off the throttle and intake tubing spikes to around 6psi. With the bov reference to the compressor housing the pressure isn't high enough to open the bov and bleed it off, but if it now sees vacuum from the intake manifold it will still bleed pressure. just realized this after my last post.
07-18-2013, 11:34 AM
#13
I don't see why the bov would need vacuum to open? i thought they open up when they see a spike in boost that overcomes the spring pressure, and that's what opens them up. I suppose a vacuum pulling on the diaphragm helps open it as well... It seems a little odd and unsafe to have a bov open letting anything into the intake path while at idle. However, the bov does seem to be working properly and i can hear it bleeding pressure when letting off the throttle.
Does it hurt anything to have both the bov and wastegate coming from the compressor housing? I'd assume both would still work properly.
Does it hurt anything to have both the bov and wastegate coming from the compressor housing? I'd assume both would still work properly.
07-22-2013, 06:28 PM
#14
I figured out the wastegate issue. First time with turbo kit and did not realize what the "fire ring" was and that you were suppose to insert it into wastegate to help seal.
on the bov. I've been seriously considering putting the vacuum line for it to the compressor as well. I hate how it is wide open during idle (maybe cruising down the road not sure can't verify when driving) and just about anything could get into the intake track (dirt/debris) and into the engine.
Is there really any huge disadvantage (other than response time) putting the bov to the compressor? The chance of sucking crap through the bov to the engine out weighs the fraction of a seconds response time of the bov.
on the bov. I've been seriously considering putting the vacuum line for it to the compressor as well. I hate how it is wide open during idle (maybe cruising down the road not sure can't verify when driving) and just about anything could get into the intake track (dirt/debris) and into the engine.
Is there really any huge disadvantage (other than response time) putting the bov to the compressor? The chance of sucking crap through the bov to the engine out weighs the fraction of a seconds response time of the bov.
07-22-2013, 07:05 PM
#15
I figured out the wastegate issue. First time with turbo kit and did not realize what the "fire ring" was and that you were suppose to insert it into wastegate to help seal.
on the bov. I've been seriously considering putting the vacuum line for it to the compressor as well. I hate how it is wide open during idle (maybe cruising down the road not sure can't verify when driving) and just about anything could get into the intake track (dirt/debris) and into the engine.
Is there really any huge disadvantage (other than response time) putting the bov to the compressor? The chance of sucking crap through the bov to the engine out weighs the fraction of a seconds response time of the bov.
on the bov. I've been seriously considering putting the vacuum line for it to the compressor as well. I hate how it is wide open during idle (maybe cruising down the road not sure can't verify when driving) and just about anything could get into the intake track (dirt/debris) and into the engine.
Is there really any huge disadvantage (other than response time) putting the bov to the compressor? The chance of sucking crap through the bov to the engine out weighs the fraction of a seconds response time of the bov.
If the BOV is there to vent compressor surge when you slam the TB shut, what good is using the compressor that will be making that surge to reference from?
