Wastegae chatter!
27 September 2006, 10:31 AM
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Wastegae chatter!
Hi all, whats the best way to get the wastegate chatter like on the WRC cars? I have a MY00 with just a GPfilter and decat center. Thanks in advance if anyone answers.
27 September 2006, 10:42 AM
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If im right and i may not be, most of the noise is due to the anti lag turbo system (explosion in manifold due to fuel being injected in there to keep turbo spinning) hence banging flames and chattering. Lots of boost shut throttle = noise etc.
Wastegate noise you probly wont hear, external wastegates sometimes vent gas to "air" but this sounds more like loud exhaust leak for a split second.
The noise i think your after you can get by a vent to atmoshere dump valve, but i know on later cars if you fit one of these instead of the recirculating type you will get riunning problems.
Jase
Wastegate noise you probly wont hear, external wastegates sometimes vent gas to "air" but this sounds more like loud exhaust leak for a split second.
The noise i think your after you can get by a vent to atmoshere dump valve, but i know on later cars if you fit one of these instead of the recirculating type you will get riunning problems.
Jase
27 September 2006, 02:38 PM
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the noise is actually the turbo blades stalling as the compressed air in the inlet manifold / intercooler has no where to go when the throttle butterfly is shut and passed back through the turbo.. the blades stall causing the chatter noise.. I expect there is something documenting it as a myth somewhere on the net..
google search.. yep
borrowed from http://en.wikipedia.org/wiki/Wastegate
You can get it simply by removing your dump valve. . depending on the turbo and the bearings use it will be okay or it will blow the bearings or brake the blades off the compressor wheel.
TD05 or Garrett turbos are fine with no dump valves.. IHI VF series turbos are not okay without a dump valve.
I am not actually sure about the TD04 turbo whcih is what is fitted to the MY00 (assuming you doesn't have an STi).. but running no dump valve and braking the turbo would be a nice reason to fit a bigger one
louder exhaust when the external wastegate is open if it vents to atmosphere but for all the time it is open.. ie. most of the time the car is on boost.
Simon
google search.. yep
Wastegate Chatter Myth
There is a common myth in the automotive world about so called "wastegate chatter", a noise created on lifting off the throttle in a turbocharged car. The sound is commonly described as a chipmunk or a rattlesnake and is often stated incorrectly as being a result of the turbo's wastegate closing.
The noise is in fact the air compressed by the turbo passing back through the compressor housing of the turbo after having hit the now closed throttle plate.
A BOV (Blow Off Valve) will usually eliminate this noise, but in some cases, i.e. where the BOV doesn't open fast enough or is setup to only react to high boost, some chatter will remain.
The chatter noise is very noticable on WRC Rally cars, where no BOV is allowed.
There is a common myth in the automotive world about so called "wastegate chatter", a noise created on lifting off the throttle in a turbocharged car. The sound is commonly described as a chipmunk or a rattlesnake and is often stated incorrectly as being a result of the turbo's wastegate closing.
The noise is in fact the air compressed by the turbo passing back through the compressor housing of the turbo after having hit the now closed throttle plate.
A BOV (Blow Off Valve) will usually eliminate this noise, but in some cases, i.e. where the BOV doesn't open fast enough or is setup to only react to high boost, some chatter will remain.
The chatter noise is very noticable on WRC Rally cars, where no BOV is allowed.
You can get it simply by removing your dump valve. . depending on the turbo and the bearings use it will be okay or it will blow the bearings or brake the blades off the compressor wheel.
TD05 or Garrett turbos are fine with no dump valves.. IHI VF series turbos are not okay without a dump valve.
I am not actually sure about the TD04 turbo whcih is what is fitted to the MY00 (assuming you doesn't have an STi).. but running no dump valve and braking the turbo would be a nice reason to fit a bigger one
Originally Posted by j900ase
Wastegate noise you probly wont hear, external wastegates sometimes vent gas to "air" but this sounds more like loud exhaust leak for a split second.
Jase
Jase
Simon
Last edited by Jolly Green Monster; 27 September 2006 at 02:41 PM.
27 September 2006, 06:57 PM
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Originally Posted by Jolly Green Monster
the noise is actually the turbo blades stalling as the compressed air in the inlet manifold / intercooler has no where to go when the throttle butterfly is shut and passed back through the turbo.. the blades stall causing the chatter noise.. I expect there is something documenting it as a myth somewhere on the net..
google search.. yep
borrowed from http://en.wikipedia.org/wiki/Wastegate
You can get it simply by removing your dump valve. . depending on the turbo and the bearings use it will be okay or it will blow the bearings or brake the blades off the compressor wheel.
TD05 or Garrett turbos are fine with no dump valves.. IHI VF series turbos are not okay without a dump valve.
I am not actually sure about the TD04 turbo whcih is what is fitted to the MY00 (assuming you doesn't have an STi).. but running no dump valve and braking the turbo would be a nice reason to fit a bigger one
louder exhaust when the external wastegate is open if it vents to atmosphere but for all the time it is open.. ie. most of the time the car is on boost.
Simon
google search.. yep
borrowed from http://en.wikipedia.org/wiki/Wastegate
You can get it simply by removing your dump valve. . depending on the turbo and the bearings use it will be okay or it will blow the bearings or brake the blades off the compressor wheel.
TD05 or Garrett turbos are fine with no dump valves.. IHI VF series turbos are not okay without a dump valve.
I am not actually sure about the TD04 turbo whcih is what is fitted to the MY00 (assuming you doesn't have an STi).. but running no dump valve and braking the turbo would be a nice reason to fit a bigger one
louder exhaust when the external wastegate is open if it vents to atmosphere but for all the time it is open.. ie. most of the time the car is on boost.
Simon
27 September 2006, 07:58 PM
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the turbine will be spinning if the antilag is doing it's job but will be creating more pressure still in the inlet manifold so will still chatter as the initial lift off increase in air pressure will have to go somewhere. Although it is more complicated than that as with true antilag the idle valve will be used to flow air into the engine and this in lift off pressure can be used to spin the turbo etc..
Simon
Simon
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27 September 2006, 08:54 PM
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Originally Posted by Jolly Green Monster
the turbine will be spinning if the antilag is doing it's job but will be creating more pressure still in the inlet manifold so will still chatter as the initial lift off increase in air pressure will have to go somewhere. Although it is more complicated than that as with true antilag the idle valve will be used to flow air into the engine and this in lift off pressure can be used to spin the turbo etc..
Simon
Simon
28 September 2006, 11:28 AM
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Originally Posted by Jolly Green Monster
the turbine will be spinning if the antilag is doing it's job but will be creating more pressure still in the inlet manifold so will still chatter as the initial lift off increase in air pressure will have to go somewhere. Although it is more complicated than that as with true antilag the idle valve will be used to flow air into the engine and this in lift off pressure can be used to spin the turbo etc..
Simon
Simon
Noise from air intake = compressor stall, air trying to push back wrong way.
Noise from wastegate = boost level reached, vent exhaust gas.
Yes?
Jase
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