This is probably just me worrying to much, but when I'm driving the I cant hear the turbo spool. It still builds boost like normal but I just can't hear it, I can hardly hear the bov either.Both use to be very noticable until a couple of weeks ago. Is this a problem? Should I start looking for a new turbo/bov? I couldn't find anything searching, any info or advice would be great.
P.S. This is the best site on the web! I've been using the info here to mod my RS (now RS-T) for the past year.
#104481, "RE: I Can't Hear My Turbo Spool" In response to Reply # 1
I would only worry about the turbo if you hear the turbo making grinding noises, or if it had bad shaft play. Check your ic piping first (tears, couplers coming off, ect) followed by the vac lines for BOOST LEAK
#104482, "RE: I Can't Hear My Turbo Spool" In response to Reply # 0
Originally posted by blackopsracing This is probably just me worrying to much, but when I'm driving the I cant hear the turbo spool. It still builds boost like normal but I just can't hear it, I can hardly hear the bov either.
It builds boost like normal, but you can't hear the turbo or the BOV. Hmmm...
If you were one of my patients, I would check your ears based on this conflicting information. Seriously.
2gnt: '99 RS-T, killed by a toyota, pending rebuild... Daily: Volt Daily #2: '99 EVG ebike- STOLEN by PEDRO
#104485, "RE: I Can't Hear My Turbo Spool" In response to Reply # 4
Originally posted by ez
Originally posted by blackopsracing This is probably just me worrying to much, but when I'm driving the I cant hear the turbo spool. It still builds boost like normal but I just can't hear it, I can hardly hear the bov either.
It builds boost like normal, but you can't hear the turbo or the BOV. Hmmm... If you were one of my patients, I would check your ears based on this conflicting information. Seriously.
Pfft, always gotta go throwing in that your a doctor.
#104486, "RE: I Can't Hear My Turbo Spool" In response to Reply # 5
lets examine why a turbo whistles shall we?
A whistle (common gym teacher whistle) works based on the high pressure inside the whistle squeezing past a small oriface into an area of low pressure. what if you try to make the hole in the whistle smaller with your finger? no longer whistles right? So we can determine the oriface is tuned to maintain a specific airspeed to create the sound. Same concept applied to old train whistles and the wooden train whistle you can buy as a novelty and blow into. Even a dog whistle works based off this.
Lets now apply this to your turbo. Does the whistle get created by the turbine or compressor? The turbine of course. Why not the Compressor as some idiots believe? A compressor is forcing air into a pipe and motor where the pressure rise is equal to that comming out of the compressor housing. There is no high to low pressure differential and there is no highly restrictive oriface.
Why cant i hear the turbo sucking air then like a vacuum leak? Again, you are not creating that large of a pressure differential through a restrictive opening.
Ok what about the turbine then? The turbine itself is restrictive and operates based on a high pressure of the exhaust into a low pressure downpipe. The turbine wheel moves based on the momentume and force of the exhaust pulses making it restrictive.
Now how could you stop the whistle of a turbine? The whistle action works on the basis of high pressure to low pressure with a restrictive opening. You can remove some of the restriction with a larger turbine housing or clipping the turbine wheel. If we dont want to remove the restriction then we must alter the pressure differential. A restrictive exhaust would cause the pressure in the downpipe to raise which would limit the amount if differential you have yet you will still build boost at possibly the same rate if the pressure differential is not too low.
What if the turbine stopped spinning, what would happen to the air flow? More restrictive due to the gas flow being forced to make a harder turn as it escapes the turbine housing. At some point the restriction is high enough so that air cant flow fast enough to whistle.
Now lets put this together. your still building boost but a whistle you had is now gone and you havent changed anything. If your exhaust output of the motor is the same then the exhaust must not be flowing as good as it was right? Do you have a catalytic? Possibly partially clogged? What if the pressure of the exhaust gas has dropped comming out of the motor? Possible, what are you AFR like? Spark plugs (will indicate rich or lean or even detonation), EGT's?
This should give you enough knowledge to examine your car further.
#104487, "RE: I Can't Hear My Turbo Spool" In response to Reply # 6
Originally posted by Star Turbo Talon lets examine why a turbo whistles shall we? A whistle (common gym teacher whistle) works based on the high pressure inside the whistle squeezing past a small oriface into an area of low pressure. what if you try to make the hole in the whistle smaller with your finger? no longer whistles right? So we can determine the oriface is tuned to maintain a specific airspeed to create the sound. Same concept applied to old train whistles and the wooden train whistle you can buy as a novelty and blow into. Even a dog whistle works based off this. Lets now apply this to your turbo. Does the whistle get created by the turbine or compressor? The turbine of course. Why not the Compressor as some idiots believe? A compressor is forcing air into a pipe and motor where the pressure rise is equal to that comming out of the compressor housing. There is no high to low pressure differential and there is no highly restrictive oriface. Why cant i hear the turbo sucking air then like a vacuum leak? Again, you are not creating that large of a pressure differential through a restrictive opening. Ok what about the turbine then? The turbine itself is restrictive and operates based on a high pressure of the exhaust into a low pressure downpipe. The turbine wheel moves based on the momentume and force of the exhaust pulses making it restrictive. Now how could you stop the whistle of a turbine? The whistle action works on the basis of high pressure to low pressure with a restrictive opening. You can remove some of the restriction with a larger turbine housing or clipping the turbine wheel. If we dont want to remove the restriction then we must alter the pressure differential. A restrictive exhaust would cause the pressure in the downpipe to raise which would limit the amount if differential you have yet you will still build boost at possibly the same rate if the pressure differential is not too low. What if the turbine stopped spinning, what would happen to the air flow? More restrictive due to the gas flow being forced to make a harder turn as it escapes the turbine housing. At some point the restriction is high enough so that air cant flow fast enough to whistle. Now lets put this together. your still building boost but a whistle you had is now gone and you havent changed anything. If your exhaust output of the motor is the same then the exhaust must not be flowing as good as it was right? Do you have a catalytic? Possibly partially clogged? What if the pressure of the exhaust gas has dropped comming out of the motor? Possible, what are you AFR like? Spark plugs (will indicate rich or lean or even detonation), EGT's? This should give you enough knowledge to examine your car further. Terry
While I was reading this it felt like you were solving a murder case... And at the end BAM! We found out who did it.
#104488, "RE: I Can't Hear My Turbo Spool" In response to Reply # 7 Oct-18-08 09:33 AM by 96TurboGS
Great info terry comparing a bov to a gym teacher, brings back memories, lol. Where do you have your boost gauge/waste gate teed at, is it off the compressor or is it at manifold??
EDIT: Your either are loosing pressure in the ic leading to a leak, or as terry mentioned something is getting restricted...
#104490, "RE: I Can't Hear My Turbo Spool" In response to Reply # 9
Just a quick question... what are the snap-in rings on like the Ram's WHX35's compressor intake for then? I'm just wanting to say that a guy i used to work with pulled his off, thinking it'd make it go faster, and it didn't. It did make the whistling annoyingly more evident, to him. Was that just that particular compressor housing's design, or was the ring to restrict intake volume, for maybe a drivability issue from the factory?
/>
'95 GS w/ t3/t4b FMIC, diy piping & RFL BOV MS2-Extra Fuel&Spark 50 lb/hr Holley injectors w/ 1:1 RRFPR JE 8.8:1 dish w/ Hastings Rings Eagle Rods w/ ARP bolts ARP Head studs Mild port/polish head 3" custom DP/cat section, 3" PIT catback dual MBC - 12 psi / 20psi
#104491, "RE: I Can't Hear My Turbo Spool" In response to Reply # 10 Oct-19-08 05:48 AM by Star Turbo Talon
not sure what ring your referring to....can you get a picture or diagram?
I searched and cant find any info on the setup. kinda sounds liek the "rings" might be restrictive and it forces the turbo to spool slower or work harder. Same situation if the bearings were going bad and the turbine couldnt spin as fast as it should. so that brings up a good point, a restrictive enough intake would also cause the turbo to lag more if it couldnt draft enough air in therefore reducing the turbine speed resulting in less exhaust gas flowing through the turbine housing. A good point and i think its another possability.
#104492, "RE: I Can't Hear My Turbo Spool" In response to Reply # 9
Originally posted by Star Turbo Talon Judging by your post you have no idea what you read. Its not an IC leak causing that issue.
I know what you said. We don’t know how he has his set up configured so neither answer is correct until he tells us what the problem is. Both are a possibility. Of course backpressure/Friction would always be something to look at. He could also have a throttle body not closing all the way or delaying causing less pressure in his ic piping sounding the bov. There is obviously less pressure/bad connection somewhere, that’s if there’s any problem at all.
#104494, "RE: I Can't Hear My Turbo Spool" In response to Reply # 12
Originally posted by 96TurboGS
Originally posted by Star Turbo Talon Judging by your post you have no idea what you read. Its not an IC leak causing that issue.
I know what you said. We don’t know how he has his set up configured so neither answer is correct until he tells us what the problem is. Both are a possibility. Of course backpressure/Friction would always be something to look at. He could also have a throttle body not closing all the way or delaying causing less pressure in his ic piping sounding the bov. There is obviously less pressure/bad connection somewhere, that’s if there’s any problem at all.
some people are always trying to ski uphill. your really an idiot.
#104496, "RE: I Can't Hear My Turbo Spool" In response to Reply # 13
So I took the car out to see maybe if it is my ears. Then I floored it, let off the gas and finally heard something... compressor surge. I think the bov is finished.
#104497, "RE: I Can't Hear My Turbo Spool" In response to Reply # 14
Originally posted by Star Turbo TalonOriginally posted by Star Turbo Talon some people are always trying to ski uphill. your really an idiot.
Ill be the bigger man, not trying to argue on a forum with you.
Originally posted by blackopsracing So I took the car out to see maybe if it is my ears. Then I floored it, let off the gas and finally heard something... compressor surge. I think the bov is finished.
Before you decide to ditch the bov pressure test it to make sure it’s opening up at 1 psi. Did you loosen the screw on the top of the bov? Try installing the bov on the throttle body and see if it makes a diff.
#104500, "RE: I Can't Hear My Turbo Spool" In response to Reply # 15
If you have compressor surge, that means your BOV is most likely not opening so that doesnt add up to your not hearing the turbo spool up. You might have multiple problems. Start checking the vac source to the BOV and if you have a vacuum testor (hand pump) use it to open the BOV. if you cant draw vacuum in the BOV then the diaphram has a leak/tear.
#104503, "RE: I Can't Hear My Turbo Spool" In response to Reply # 16
out of curiosity, what sort of numbers are you looking at for idle vacuum, boost psi, and how quickly does your vacuum needle go down after you floor the throttle and let off?
/>
'95 GS w/ t3/t4b FMIC, diy piping & RFL BOV MS2-Extra Fuel&Spark 50 lb/hr Holley injectors w/ 1:1 RRFPR JE 8.8:1 dish w/ Hastings Rings Eagle Rods w/ ARP bolts ARP Head studs Mild port/polish head 3" custom DP/cat section, 3" PIT catback dual MBC - 12 psi / 20psi
#104507, "RE: I Can't Hear My Turbo Spool" In response to Reply # 17
Originally posted by justins71 out of curiosity, what sort of numbers are you looking at for idle vacuum, boost psi, and how quickly does your vacuum needle go down after you floor the throttle and let off?
Idle vacuum is at about -20 psi, Boost 5 psi (wg is set at 7 but I guess there is a 2 psi loss through the fmic), and the needle drops the second I let off the gas.
#104506, "RE: I Can't Hear My Turbo Spool" In response to Reply # 16
Originally posted by Star Turbo Talon If you have compressor surge, that means your BOV is most likely not opening so that doesnt add up to your not hearing the turbo spool up. You might have multiple problems. Start checking the vac source to the BOV and if you have a vacuum testor (hand pump) use it to open the BOV. if you cant draw vacuum in the BOV then the diaphram has a leak/tear. Terry
I changed the T on the vacuum source (the line coming from the top of the throttle body) and still no luck. I don't have a vacuum tester, I'm probably going to have to buy one or is there another way to test?
#104504, "RE: I Can't Hear My Turbo Spool" In response to Reply # 5
Originally posted by teklein bla bla bla
I said nothing about being a doctor here. I could be a nurse, a PA, or a dozen other health care professionals. It frankly doesn't matter. I'm programmed to bring up such issues because I've met enough people where a peculiar change in there daily experience turns out to be signs of an underlying health issue.
I was avoiding going down the path Terry went, because the poster said the car builds boost as normal. Hence the turbo is spooling. Spooling causes noise. No intake or exhaust modifications are noted. Something does not add up. I think ears.
2gnt: '99 RS-T, killed by a toyota, pending rebuild... Daily: Volt Daily #2: '99 EVG ebike- STOLEN by PEDRO
#104505, "RE: I Can't Hear My Turbo Spool" In response to Reply # 21
Originally posted by ez
Originally posted by teklein bla bla bla
I said nothing about being a doctor here. I could be a nurse, a PA, or a dozen other health care professionals. It frankly doesn't matter. I'm programmed to bring up such issues because I've met enough people where a peculiar change in there daily experience turns out to be signs of an underlying health issue. I was avoiding going down the path Terry went, because the poster said the car builds boost as normal. Hence the turbo is spooling. Spooling causes noise. No intake or exhaust modifications are noted. Something does not add up. I think ears.
Whoa man, I was just poking fun. Didnt mean anything by it
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