TD04 Wastegate chatter

J

jayc-glanza17

Fresh Recruit
its fine mate.
im running chatter at 1.2 bar, sometimes 1.3 wen cold..
did av it running 1.6 for track and no issues what so ever.
 
corofin12345

corofin12345

Member +
its not the wastegate making the noise.. its the turbo... with no bov the pressurised air comes back through the turbine blades and the blades chop up the air and comes back out through filter.. "chatter/flutter"
 
danb87

danb87

South East England Area Rep
is it safe on other turbos as its not a good thing on the ct9.

what about a tongs hybrid ct9?
 
garya

garya

Fresh Recruit
far as i am aware mate its safe on quite a few turbos i used to have a t25 on my old renault 5 and never ran a d/v and never done any harm to it and i know alot of guys on rtoc use vnt turbos without d/v's
danb87 said:
is it safe on other turbos as its not a good thing on the ct9.

what about a tongs hybrid ct9?
Click to expand...
 
danb87

danb87

South East England Area Rep
cheers mate, any ne know for sure if its safe too do?

i was told theres a dv that gives off the same sort of sound, think it was a sard. anyone now the one?

also, im curious why some car i see they give it a little rev an it sound chattery, but others dont. would that have anything too do with an external wastegate?
 
danb87

danb87

South East England Area Rep
is it safe too bung up the dv pipe too get the flutter sound on the hybrid ct9? or not recomended? as i dont wanna damage my turbo
 
Last edited:
danb87

danb87

South East England Area Rep
can it damage turbo tho? i run a ct9 tongs hybrid, an quite like the flutter sound. but heard its not good for them. can anyone confirm this?
 
J25GTi

J25GTi

Lifer
I have just logged on, and 5 out of the first 20 new topics are about chatter,

Do a search, it is covered daily
 
danb87

danb87

South East England Area Rep
J25GTi said:
I have just logged on, and 5 out of the first 20 new topics are about chatter,

Do a search, it is covered daily
Click to expand...

just logged on an this the only one i can see. so i would apriciate some one who could confirm this.

theres nothing conclusive about the tongs turbo. only td04s etc. i want too know about this turbo not any other turbo
 
J25GTi

J25GTi

Lifer
All turbos are the same. Td04, hybrid etc. Some people say its fine. Others don't. You need to make your own decision, I've ran mine like it for over a year
 
corofin12345

corofin12345

Member +
its a gray area but i say fuck it, do what you want... i havent heard of one case of turbo failure cause of people bunging up the pipe to get flutter.. but you do even have to bung up the pipe.. juat take vacuum of bov and put a bolt in vacuum pipe.. that or do what i did in the link above
 
Texx

Texx

Super Moderator
The idea of a blow off valve or air bypass valve is to reduce some of the loss in the spooling performance of the turbo when the throttle is reopened after lifting off i.e. after a gear change. Lets take a full throttle gear change from 2nd to 3rd and break it down a little to see what's happening.

So, the throttle plate is wide open, the turbo is forcing air into the engine at it's maximum set pressure, the engine is reaching it's rev point from which the driver is required to change up into 3rd, the clutch is disengaged and the throttle plate is closed, at the moment the throttle plate is closed there will still be some compressed air or boost that remains in the intake system between the outlet of the turbo's compressor housing and the now closed throttle plate, this pressurised air will not just stay there waiting for the throttle plate to be reopened it'll start to escape through the only opening in the system, this opening is the intake side of the turbo's compressor housing via the still spinning compressor wheel, as the compressed air or boost passes back through the compressor wheel it makes a chopping or chattering sound and slows the wheel down in the process, 3rd gear is now selected by the driver, the clutch is engaged, the throttle plate is reopened and the turbo begins to spool again creating maximum boost pressure.

This scenario is not necessarily bad for the turbo, once the throttle plate has been closed there will only be a small amount of exhaust gas entering the turbo's turbine housing and so there will be very little energy there to maintain the speed of the turbine wheel. With the compressed air or boost passing back through the compressor wheel and no exhaust energy to spool the turbine wheel the turbo will begin to stall. Stall means the turbo slows down quite quickly, it doesn't actually stop spinning as the engine is still running and exhausting hot gases into the turbine housing. The problem here is when full boost is demanded from the turbo again and the driver has to wait for the turbo to spool back up from it's stalled speed, this is where the blow off valve or air bypass valve comes in.

Air bypass valve is a better description, as it's function is to allow compressed air or boost to bypass the compressor housing when exiting the intake system during closed throttle. Now the compressed air or boost is no longer passing back through the compressor housing it's also no longer causing the turbo to stall, so when full boost is demanded again by the driver the turbo is spinning at a faster speed than it would of been without the air bypass valve. This will reduce the time it takes to the turbo to reach full boost pressure again.

So in summary, you can run with or without a BOV and not have to worry about causing any damage to the turbo, but a BOV will provide some benefit towards the spool performance of the turbo.


Compressor stall does not cause any harm, but don't get that confused with compressor surge under load. Compressor surge when the engine is under load is very bad for the turbo but has no relation to the BOV.
 
danb87

danb87

South East England Area Rep
bucketep91 said:
it will be fine buddy, plenty ct9's running like that with no issues. I ran my tongs hybrid with no dv for a year with no issues
Click to expand...

corofin12345 said:
its a gray area but i say fuck it, do what you want... i havent heard of one case of turbo failure cause of people bunging up the pipe to get flutter.. but you do even have to bung up the pipe.. juat take vacuum of bov and put a bolt in vacuum pipe.. that or do what i did in the link above
Click to expand...

Texx said:
The idea of a blow off valve or air bypass valve is to reduce some of the loss in the spooling performance of the turbo when the throttle is reopened after lifting off i.e. after a gear change. Lets take a full throttle gear change from 2nd to 3rd and break it down a little to see what's happening.

So, the throttle plate is wide open, the turbo is forcing air into the engine at it's maximum set pressure, the engine is reaching it's rev point from which the driver is required to change up into 3rd, the clutch is disengaged and the throttle plate is closed, at the moment the throttle plate is closed there will still be some compressed air or boost that remains in the intake system between the outlet of the turbo's compressor housing and the now closed throttle plate, this pressurised air will not just stay there waiting for the throttle plate to be reopened it'll start to escape through the only opening in the system, this opening is the intake side of the turbo's compressor housing via the still spinning compressor wheel, as the compressed air or boost passes back through the compressor wheel it makes a chopping or chattering sound and slows the wheel down in the process, 3rd gear is now selected by the driver, the clutch is engaged, the throttle plate is reopened and the turbo begins to spool again creating maximum boost pressure.

This scenario is not necessarily bad for the turbo, once the throttle plate has been closed there will only be a small amount of exhaust gas entering the turbo's turbine housing and so there will be very little energy there to maintain the speed of the turbine wheel. With the compressed air or boost passing back through the compressor wheel and no exhaust energy to spool the turbine wheel the turbo will begin to stall. Stall means the turbo slows down quite quickly, it doesn't actually stop spinning as the engine is still running and exhausting hot gases into the turbine housing. The problem here is when full boost is demanded from the turbo again and the driver has to wait for the turbo to spool back up from it's stalled speed, this is where the blow off valve or air bypass valve comes in.

Air bypass valve is a better description, as it's function is to allow compressed air or boost to bypass the compressor housing when exiting the intake system during closed throttle. Now the compressed air or boost is no longer passing back through the compressor housing it's also no longer causing the turbo to stall, so when full boost is demanded again by the driver the turbo is spinning at a faster speed than it would of been without the air bypass valve. This will reduce the time it takes to the turbo to reach full boost pressure again.

So in summary, you can run with or without a BOV and not have to worry about causing any damage to the turbo, but a BOV will provide some benefit towards the spool performance of the turbo.


Compressor stall does not cause any harm, but don't get that confused with compressor surge under load. Compressor surge when the engine is under load is very bad for the turbo but has no relation to the BOV.
Click to expand...

cheers for clearing that up lads
 
B

bumblebee

Member +
Texx said:
The idea of a blow off valve or air bypass valve is to reduce some of the loss in the spooling performance of the turbo when the throttle is reopened after lifting off i.e. after a gear change. Lets take a full throttle gear change from 2nd to 3rd and break it down a little to see what's happening.

So, the throttle plate is wide open, the turbo is forcing air into the engine at it's maximum set pressure, the engine is reaching it's rev point from which the driver is required to change up into 3rd, the clutch is disengaged and the throttle plate is closed, at the moment the throttle plate is closed there will still be some compressed air or boost that remains in the intake system between the outlet of the turbo's compressor housing and the now closed throttle plate, this pressurised air will not just stay there waiting for the throttle plate to be reopened it'll start to escape through the only opening in the system, this opening is the intake side of the turbo's compressor housing via the still spinning compressor wheel, as the compressed air or boost passes back through the compressor wheel it makes a chopping or chattering sound and slows the wheel down in the process, 3rd gear is now selected by the driver, the clutch is engaged, the throttle plate is reopened and the turbo begins to spool again creating maximum boost pressure.

This scenario is not necessarily bad for the turbo, once the throttle plate has been closed there will only be a small amount of exhaust gas entering the turbo's turbine housing and so there will be very little energy there to maintain the speed of the turbine wheel. With the compressed air or boost passing back through the compressor wheel and no exhaust energy to spool the turbine wheel the turbo will begin to stall. Stall means the turbo slows down quite quickly, it doesn't actually stop spinning as the engine is still running and exhausting hot gases into the turbine housing. The problem here is when full boost is demanded from the turbo again and the driver has to wait for the turbo to spool back up from it's stalled speed, this is where the blow off valve or air bypass valve comes in.

Air bypass valve is a better description, as it's function is to allow compressed air or boost to bypass the compressor housing when exiting the intake system during closed throttle. Now the compressed air or boost is no longer passing back through the compressor housing it's also no longer causing the turbo to stall, so when full boost is demanded again by the driver the turbo is spinning at a faster speed than it would of been without the air bypass valve. This will reduce the time it takes to the turbo to reach full boost pressure again.

So in summary, you can run with or without a BOV and not have to worry about causing any damage to the turbo, but a BOV will provide some benefit towards the spool performance of the turbo.


Compressor stall does not cause any harm, but don't get that confused with compressor surge under load. Compressor surge when the engine is under load is very bad for the turbo but has no relation to the BOV.
Click to expand...

Repped!! :rockon:
 
corofin12345

corofin12345

Member +
Texx said:
The idea of a blow off valve or air bypass valve is to reduce some of the loss in the spooling performance of the turbo when the throttle is reopened after lifting off i.e. after a gear change. Lets take a full throttle gear change from 2nd to 3rd and break it down a little to see what's happening.

So, the throttle plate is wide open, the turbo is forcing air into the engine at it's maximum set pressure, the engine is reaching it's rev point from which the driver is required to change up into 3rd, the clutch is disengaged and the throttle plate is closed, at the moment the throttle plate is closed there will still be some compressed air or boost that remains in the intake system between the outlet of the turbo's compressor housing and the now closed throttle plate, this pressurised air will not just stay there waiting for the throttle plate to be reopened it'll start to escape through the only opening in the system, this opening is the intake side of the turbo's compressor housing via the still spinning compressor wheel, as the compressed air or boost passes back through the compressor wheel it makes a chopping or chattering sound and slows the wheel down in the process, 3rd gear is now selected by the driver, the clutch is engaged, the throttle plate is reopened and the turbo begins to spool again creating maximum boost pressure.

This scenario is not necessarily bad for the turbo, once the throttle plate has been closed there will only be a small amount of exhaust gas entering the turbo's turbine housing and so there will be very little energy there to maintain the speed of the turbine wheel. With the compressed air or boost passing back through the compressor wheel and no exhaust energy to spool the turbine wheel the turbo will begin to stall. Stall means the turbo slows down quite quickly, it doesn't actually stop spinning as the engine is still running and exhausting hot gases into the turbine housing. The problem here is when full boost is demanded from the turbo again and the driver has to wait for the turbo to spool back up from it's stalled speed, this is where the blow off valve or air bypass valve comes in.

Air bypass valve is a better description, as it's function is to allow compressed air or boost to bypass the compressor housing when exiting the intake system during closed throttle. Now the compressed air or boost is no longer passing back through the compressor housing it's also no longer causing the turbo to stall, so when full boost is demanded again by the driver the turbo is spinning at a faster speed than it would of been without the air bypass valve. This will reduce the time it takes to the turbo to reach full boost pressure again.

So in summary, you can run with or without a BOV and not have to worry about causing any damage to the turbo, but a BOV will provide some benefit towards the spool performance of the turbo.


Compressor stall does not cause any harm, but don't get that confused with compressor surge under load. Compressor surge when the engine is under load is very bad for the turbo but has no relation to the BOV.
Click to expand...

just about exactly my thoughts man but one thing i do find is if your good with your left and right foot (quick shifting) i have absolutely no lag between gears running with the flutter theory.. i put it down to the excess pressure been gobbled back up but it all depends on how good/fast you are at selecting and getting back on the throttle... ;)
 
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