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Author Stupid question!
Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
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17th May 04 at 11:26   View User's Profile U2U Member Reply With Quote

they do have wastegates but they don't have dumpvalves
Nick-S
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Registered: 3rd Mar 04
Location: Leigh. Drives: RS Megane 230 F1 Team R26
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17th May 04 at 11:28   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GIBBS
well i aint gotta clue what chatter you are 'talking' about, but it certainly IS the wastegate that provides the renowned chatter.

Matt
I fink ull find ur wrong mate

quote:
Originally posted by Adam
they do have wastegates but they don't have dumpvalves

who sed anythin about a dumpvalve?
GIBBS
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Registered: 22nd Feb 01
Location: Kent, Jap Car Importer :)
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17th May 04 at 11:30   View User's Profile U2U Member Reply With Quote

right so, with his arguement it's because the air isn't being released while off throttle therefore the air is being forced over the blades yes?
1. this is the reason alot of turbo's get damaged, serious design flaw if this was as common as you say/think.
2. therefore a dump valve, releasing the air before the turbo when you come off throttle would solve this so called 'chattering'
3. why then how come on our single tubbie rx7, when we have a dump valve, AND an external wastegate do we get the chatter still?

the chatter you talk about IS the wastegate.
Paul_J
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Registered: 6th Jun 02
Location: London
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17th May 04 at 11:31   View User's Profile U2U Member Reply With Quote

I know the noise you mean...

It's not a whistle like adam was talking about... and its not a VRrrrrrmmm - Tish release in pressure...

It's a 'chatter' noise - if you watched that vid of that supra the other day that did like a 8.5 sec 1/4 mile listen to his car after his burn out as he blips the throttle ...

How does it make this sound?

hehe - I don't know. Though what you copied and pasted seemed about right.
Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
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17th May 04 at 11:32   View User's Profile U2U Member Reply With Quote

it is the wastegate/actuator that makes the chatter,
Nick-S
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Registered: 3rd Mar 04
Location: Leigh. Drives: RS Megane 230 F1 Team R26
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17th May 04 at 11:32   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GIBBS
right so, with his arguement it's because the air isn't being released while off throttle therefore the air is being forced over the blades yes?
1. this is the reason alot of turbo's get damaged, serious design flaw if this was as common as you say/think.
2. therefore a dump valve, releasing the air before the turbo when you come off throttle would solve this so called 'chattering'
3. why then how come on our single tubbie rx7, when we have a dump valve, AND an external wastegate do we get the chatter still?

the chatter you talk about IS the wastegate.
yes it dose damage if u are runin high boost
Nick-S
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Registered: 3rd Mar 04
Location: Leigh. Drives: RS Megane 230 F1 Team R26
User status: Offline
17th May 04 at 11:33   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by Paul_J
I know the noise you mean...

It's not a whistle like adam was talking about... and its not a VRrrrrrmmm - Tish release in pressure...

It's a 'chatter' noise - if you watched that vid of that supra the other day that did like a 8.5 sec 1/4 mile listen to his car after his burn out as he blips the throttle ...

How does it make this sound?

hehe - I don't know. Though what you copied and pasted seemed about right.
read my earlyer post i av explaned it
GIBBS
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Registered: 22nd Feb 01
Location: Kent, Jap Car Importer :)
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17th May 04 at 11:34   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GSi_16v
quote:
Originally posted by GIBBS
right so, with his arguement it's because the air isn't being released while off throttle therefore the air is being forced over the blades yes?
1. this is the reason alot of turbo's get damaged, serious design flaw if this was as common as you say/think.
2. therefore a dump valve, releasing the air before the turbo when you come off throttle would solve this so called 'chattering'
3. why then how come on our single tubbie rx7, when we have a dump valve, AND an external wastegate do we get the chatter still?

the chatter you talk about IS the wastegate.
yes it dose damage if u are runin high boost


hence why people use dump valves to release the pressure before the turbo, and larger external wastegates to stop overboost, and that is what creats the chatter when coming off boost.
GIBBS
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Registered: 22nd Feb 01
Location: Kent, Jap Car Importer :)
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17th May 04 at 11:34   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by Adam
it is the wastegate/actuator that makes the chatter,


Nick-S
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Registered: 3rd Mar 04
Location: Leigh. Drives: RS Megane 230 F1 Team R26
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17th May 04 at 11:34   View User's Profile U2U Member Reply With Quote

The wastegate is a flap inside the turbo which opens to leak boost out when it reaches a set amount. The wastegate actuator contains a spring and diaphragm that senses the pressure and opens the wastegate

A dump valve (blow off valve outside Europe) is similar in construction to an actuator, in that it contains a spring and diaphragm (or piston). It's job is to open when the inlet manifold is in vacuum - throttle off on a turbo car.



The wastegate is a flap inside the turbo which opens to leak boost out when it reaches a set amount. The wastegate actuator contains a spring and diaphragm that senses the pressure and opens the wastegate

A dump valve (blow off valve outside Europe) is similar in construction to an actuator, in that it contains a spring and diaphragm (or piston). It's job is to open when the inlet manifold is in vacuum - throttle off on a turbo car.

with out a dump valve when the throttle is lifted, boost produced by the turbo that has not yet entered the inlet has nowhere to go. Normally it bounces off the closed throttle plate and back towards the turbo, where it hits the spinning blades and reverberates off them, making the chattering noise. This can cause bearing failure and also in severe cases, the impeller blades to shatter and get sucked into the engine. Not a pretty sight. if u are runin high boost


[Edited on 17-05-2004 by GSi_16v]
Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
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17th May 04 at 11:35   View User's Profile U2U Member Reply With Quote

you haven't got a clue

3 things cause chatter

Anti-lag systems
Some types of dump valve
Wastegates
Nick-S
Member

Registered: 3rd Mar 04
Location: Leigh. Drives: RS Megane 230 F1 Team R26
User status: Offline
17th May 04 at 11:36   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GIBBS
quote:
Originally posted by GSi_16v
quote:
Originally posted by GIBBS
right so, with his arguement it's because the air isn't being released while off throttle therefore the air is being forced over the blades yes?
1. this is the reason alot of turbo's get damaged, serious design flaw if this was as common as you say/think.
2. therefore a dump valve, releasing the air before the turbo when you come off throttle would solve this so called 'chattering'
3. why then how come on our single tubbie rx7, when we have a dump valve, AND an external wastegate do we get the chatter still?

the chatter you talk about IS the wastegate.
yes it dose damage if u are runin high boost


hence why people use dump valves to release the pressure before the turbo, and larger external wastegates to stop overboost, and that is what creats the chatter when coming off boost.

the nose a dump valve makes is not called chatter
Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
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17th May 04 at 11:36   View User's Profile U2U Member Reply With Quote

you can get different types of dump valve, some tish some chatter
GIBBS
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Registered: 22nd Feb 01
Location: Kent, Jap Car Importer :)
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17th May 04 at 11:36   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GSi_16v
The wastegate is a flap inside the turbo which opens to leak boost out when it reaches a set amount. The wastegate actuator contains a spring and diaphragm that senses the pressure and opens the wastegate

A dump valve (blow off valve outside Europe) is similar in construction to an actuator, in that it contains a spring and diaphragm (or piston). It's job is to open when the inlet manifold is in vacuum - throttle off on a turbo car.

Posted: Thu Mar 25, 2004 1:53 pm Post subject:

--------------------------------------------------------------------------------

The wastegate is a flap inside the turbo which opens to leak boost out when it reaches a set amount. The wastegate actuator contains a spring and diaphragm that senses the pressure and opens the wastegate, as standard this happens at ~6psi (manifold pressure).

A dump valve (blow off valve outside Europe) is similar in construction to an actuator, in that it contains a spring and diaphragm (or piston). It's job is to open when the inlet manifold is in vacuum - throttle off on a turbo car.

with out a dump valve when the throttle is lifted, boost produced by the turbo that has not yet entered the inlet has nowhere to go. Normally it bounces off the closed throttle plate and back towards the turbo, where it hits the spinning blades and reverberates off them, making the chattering noise. This can cause bearing failure and also in severe cases, the impeller blades to shatter and get sucked into the engine. Not a pretty sight. if u are runin high boost



dependant on turbo configuration, larger aftermarket turbo's do not have internal wastegate's and use an external wastegate which makes the noise.
i don't see the point at all in you posting all the above, it proves nothing towards your point.
Paul_J
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Registered: 6th Jun 02
Location: London
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17th May 04 at 11:36   View User's Profile U2U Member Reply With Quote

Hmm - just a thought but you've got to have somewhere for sound to escape to hear it... So perhaps maybe your both right...

As you lift off the air hits the blades (creates the chatter noise) - and then the waste gate opens to let it out and out comes all the wasted air and the noise...

Paul J
GIBBS
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Registered: 22nd Feb 01
Location: Kent, Jap Car Importer :)
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17th May 04 at 11:36   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GSi_16v
quote:
Originally posted by GIBBS
quote:
Originally posted by GSi_16v
quote:
Originally posted by GIBBS
right so, with his arguement it's because the air isn't being released while off throttle therefore the air is being forced over the blades yes?
1. this is the reason alot of turbo's get damaged, serious design flaw if this was as common as you say/think.
2. therefore a dump valve, releasing the air before the turbo when you come off throttle would solve this so called 'chattering'
3. why then how come on our single tubbie rx7, when we have a dump valve, AND an external wastegate do we get the chatter still?

the chatter you talk about IS the wastegate.
yes it dose damage if u are runin high boost


hence why people use dump valves to release the pressure before the turbo, and larger external wastegates to stop overboost, and that is what creats the chatter when coming off boost.

the nose a dump valve makes is not called chatter


yes i know, it's the WASTEGATE.
Nick-S
Member

Registered: 3rd Mar 04
Location: Leigh. Drives: RS Megane 230 F1 Team R26
User status: Offline
17th May 04 at 11:37   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by Adam
you haven't got a clue

3 things cause chatter

Anti-lag systems
Some types of dump valve
Wastegates
how many road cars do u see runin an anti lag system
Nick-S
Member

Registered: 3rd Mar 04
Location: Leigh. Drives: RS Megane 230 F1 Team R26
User status: Offline
17th May 04 at 11:39   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GIBBS
quote:
Originally posted by GSi_16v
quote:
Originally posted by GIBBS
quote:
Originally posted by GSi_16v
quote:
Originally posted by GIBBS
right so, with his arguement it's because the air isn't being released while off throttle therefore the air is being forced over the blades yes?
1. this is the reason alot of turbo's get damaged, serious design flaw if this was as common as you say/think.
2. therefore a dump valve, releasing the air before the turbo when you come off throttle would solve this so called 'chattering'
3. why then how come on our single tubbie rx7, when we have a dump valve, AND an external wastegate do we get the chatter still?

the chatter you talk about IS the wastegate.
yes it dose damage if u are runin high boost


hence why people use dump valves to release the pressure before the turbo, and larger external wastegates to stop overboost, and that is what creats the chatter when coming off boost.

the nose a dump valve makes is not called chatter


yes i know, it's the WASTEGATE.
it is not the wastegate that causes chatter. Chatter is the air reverberating off the turbo blades when the throttle is closed
GIBBS
Member

Registered: 22nd Feb 01
Location: Kent, Jap Car Importer :)
User status: Offline
17th May 04 at 11:39   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GSi_16v
quote:
Originally posted by Adam
you haven't got a clue

3 things cause chatter

Anti-lag systems
Some types of dump valve
Wastegates
how many road cars do u see runin an anti lag system


probably as many as you see car's making the loud chattering noise from just the air travelling back over the blades
all car's will come with a form of dump valve, even if it's a plastic recirc, but it will stop the air traveling back into the turbo and damaging it.
Nick-S
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Registered: 3rd Mar 04
Location: Leigh. Drives: RS Megane 230 F1 Team R26
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17th May 04 at 11:40   View User's Profile U2U Member Reply With Quote

i will say it again

Think about what happens when you lift off:

The turbo isn't being asked to provide boost, so there is no need for the wastegate to open (which it only does when max boost is reached). Therefore it would not be opening and closing.

Even so, the wastegate is a metal flap against the metal casting of the turbo's exhaust housing. If it were to fluctuate, it would not produce the sound we know as chatter, more a metallic clattering sound.

The only sound you'll ever hear from the wastegate is external ones venting to atmosphere
GIBBS
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Registered: 22nd Feb 01
Location: Kent, Jap Car Importer :)
User status: Offline
17th May 04 at 11:41   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GSi_16v
quote:
Originally posted by GIBBS
quote:
Originally posted by GSi_16v
quote:
Originally posted by GIBBS
quote:
Originally posted by GSi_16v
quote:
Originally posted by GIBBS
right so, with his arguement it's because the air isn't being released while off throttle therefore the air is being forced over the blades yes?
1. this is the reason alot of turbo's get damaged, serious design flaw if this was as common as you say/think.
2. therefore a dump valve, releasing the air before the turbo when you come off throttle would solve this so called 'chattering'
3. why then how come on our single tubbie rx7, when we have a dump valve, AND an external wastegate do we get the chatter still?

the chatter you talk about IS the wastegate.
yes it dose damage if u are runin high boost


hence why people use dump valves to release the pressure before the turbo, and larger external wastegates to stop overboost, and that is what creats the chatter when coming off boost.

the nose a dump valve makes is not called chatter


yes i know, it's the WASTEGATE.
it is not the wastegate that causes chatter. Chatter is the air reverberating off the turbo blades when the throttle is closed



u just don't understand do you.

think of it this way, u own a corsa diesel turbo i presume, you have had to ask this 'stupid question' on a corsasport forum.
i drive, have owned and own many big power jap turbo car's, and don't have the need to ask what makes a chatter.
GIBBS
Member

Registered: 22nd Feb 01
Location: Kent, Jap Car Importer :)
User status: Offline
17th May 04 at 11:43   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GSi_16v
i will say it again

Think about what happens when you lift off:

The turbo isn't being asked to provide boost, so there is no need for the wastegate to open (which it only does when max boost is reached). Therefore it would not be opening and closing.

Even so, the wastegate is a metal flap against the metal casting of the turbo's exhaust housing. If it were to fluctuate, it would not produce the sound we know as chatter, more a metallic clattering sound.

The only sound you'll ever hear from the wastegate is external ones venting to atmosphere


yes, this is the chatter, it's very rare you'll get a chatter from a stock turbo with internal wastegate, but it does happen. all car's will be provided with some form of dv be it recirc or vent to stop air reaching the turbo. the chatter is not from the turbo's blades
Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
User status: Offline
17th May 04 at 11:43   View User's Profile U2U Member Reply With Quote

the wastegate opens when you accelerate and will open when you get to a preset amount of boost

when you decelerate then the noise would come from a dumpvale

The wastegate would produce a chattery sound as it would never hit the sides, as soon as it opens the boost drops and it starts to close
Nick-S
Member

Registered: 3rd Mar 04
Location: Leigh. Drives: RS Megane 230 F1 Team R26
User status: Offline
17th May 04 at 11:43   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by GIBBS
quote:
Originally posted by GSi_16v
quote:
Originally posted by Adam
you haven't got a clue

3 things cause chatter

Anti-lag systems
Some types of dump valve
Wastegates
how many road cars do u see runin an anti lag system


probably as many as you see car's making the loud chattering noise from just the air travelling back over the blades
all car's will come with a form of dump valve, even if it's a plastic recirc, but it will stop the air traveling back into the turbo and damaging it.

my mates FRST chatters n he dose not run anti lag. he also has no dump valve. yes chatter may cause damage if u runin very high boost but at standard RS turbo it wont.
it is not the waste gate that causes the noise.
Adam
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Registered: 1st May 01
Location: Hurstbourne Tarrant
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17th May 04 at 11:43   View User's Profile U2U Member Reply With Quote

if you have air trying to pass over the turbo in the wrong direction your turbo isn't going to last long

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