Constipated Turbo (Can't Dump)

S

sdutton007

Member +
Bit of a strange problem....

I have some blitz dump valve w/ trumpet on my ep82 (came with it from japan) - and it's been working fine until a few days ago, when *sometimes* it won't make the loud psssst sound like it should, but i can hear the wastegate instead!

Anyone have any ideas? I thought a loose pipe at first but all the vacuum pipes in the engine bay seem to be on perfectly!

Cheers guys
 
Rory

Rory

Lifer
Sounds like your dump valve is seizing up, whip it off and give it a good clean, and make sure the pistons moves.
 
S

sdutton007

Member +
Rory said:
Sounds like your dump valve is seizing up, whip it off and give it a good clean, and make sure the pistons moves.
Click to expand...

OK, cheers - i'll try that on the weekend.

fastglanza said:
and u cant hear the wastegate....compressor stall
Click to expand...

I can hear the wastegate when its too lazy to dump.

What's compressor stall? Is that when the air pressure tries to go the wrong way through the turbo and stalls it?
 
Monkfish

Monkfish

Member +
Wastegates don't make noises! End of. No if's, no but's, they don't make noises. "Wastegate chatter" is a myth.

This is compressor stall...
 
S

sdutton007

Member +
So 'Wastegate chatter" = compressor stall ?????

Does this mean that the turbo is getting damaged slightly every time it happens???

Monkfish said:
Wastegates don't make noises! End of. No if's, no but's, they don't make noises. "Wastegate chatter" is a myth.

This is compressor stall...
Click to expand...
 
Monkfish

Monkfish

Member +
sdutton007 said:
So 'Wastegate chatter" = compressor stall ?????

Does this mean that the turbo is getting damaged slightly every time it happens???
Click to expand...

Wastegate chatter doesn't exist, it is a term that started (Probably in Max Power) that most people incorrectly use to describe compressor stall. As for the damage caused, there are two schools of thought on that, yes it does and no it doesn't. Let's not start a debate on that though, it's been covered about 400 million times. ;)
 
A

Adam_Glanza

Member +
well that arguement has been going on forever and a day.

some say it does some say it doesnt.

theres no proof to say it does or doesnt..

on the ct9 its not super advisable but aslong as your not running huge boost its normally ok as alot of others dont run with bov's and there turbos have lasted for a few years
 
S

sdutton007

Member +
Just looked up "Compressor Stall" on wikipedia:


Compressor Stall:
All compressor stalls result in a loss of engine power. This power failure may only be momentary (occurring so quickly it is barely registered on engine instruments), or may shut the engine down completely (that is, causing a flameout). When a compressor stall affects the airflow through the entire engine it is also known as a compressor surge (although definitions differ, and often the terms are used interchangeably).

Compressor stalls can cause a compressor surge which in turn can cause one or more extremely loud bangs emanating from the engine as the combustion process "backfires". This may be accompanied by an increased exhaust gas temperature, and yawing of the aircraft in the direction of the affected engine. When a compressor surge occurs pressure at the compressor stages is lower than at the combustion chamber causing an adverse pressure gradient. This causes a back flow of air through the compressor which is noticed as a loud bang with intense aerodynamic buffeting.

The effects of a stall can vary. A minor stall may create an alarming noise but have little other effect. On the other hand, a violent compressor surge might completely destroy the engine and set it on fire.



Wastegate Chatter:
There is a common myth in the automotive world about so called "wastegate chatter" or "turbo flutter", 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 wheel of the turbo after the airflow is abruptly halted by the throttle plate closing. However, in some cases, i.e. where it doesn't open fast enough or is set up to only react to high boost, some chatter will remain. Surge can occur on diesels when the turbo is attempting to pressurize the air at a higher pressure ratio than the compressor wheel can flow at a given speed. Diesels have no use for a Blow off Valve as they do not have a throttle.
The chatter noise is very noticeable on WRC Rally cars, where no BOV is allowed.
 
Monkfish

Monkfish

Member +
There is a key sentence in that little bit of info you need to pick up on, which contains a specific word. Here, let me point you in the right direction...

Wikipedia said:
"This may be accompanied by an increased exhaust gas temperature, and yawing of the aircraft in the direction of the affected engine."
Click to expand...

:p
 
S

sdutton007

Member +
Monkfish said:
There is a key sentence in that little bit of info you need to pick up on, which contains a specific word. Here, let me point you in the right direction...

:p
Click to expand...

yes, i read the entire article. it applies to aircraft AND cars! They both use combustion engines and use the same principles of operation!
 
Monkfish

Monkfish

Member +
sdutton007 said:
yes, i read the entire article. it applies to aircraft AND cars! They both use combustion engines and use the same principles of operation!
Click to expand...

FAIL

Compressor stall in a jet engine is a completely different ball game to that of compressor stall in a turbo strapped to an internal combustion engine. They happen for different reasons with massively different concequences.

To conclude this topic...

- Your dump valve is knackered, or needs stripping, cleaning and rebuilding.
- Wastegate chatter does not exist
- Compressor stall in a jet engine usually results in lots of brown pants and a possible broken engine.
- Compressor stall in a turbo results in some funky sounding chatter from the intake system, either sounding like a squirrel or a pigeon depending on whether there is an air filter fitted and how long the intake piping, if any, is. It also doesn't result in damage, death or destruction.

:D
 
T

Toby@ToyTuning.com

Banned - DO NOT BUY FROM TOYTUNING
Not all planes run jet engines :p

Most planes run conventional engines which are very similar to cars, they work on the exact same principles. One of my closest friends is a plane mechanic and we apply the same principles to our cars :)

T
 
S

sdutton007

Member +
Monkfish said:
FAIL

Compressor stall in a jet engine is a completely different ball game to that of compressor stall in a turbo strapped to an internal combustion engine. They happen for different reasons with massively different concequences.

To conclude this topic...

- Your dump valve is knackered, or needs stripping, cleaning and rebuilding.
- Wastegate chatter does not exist
- Compressor stall in a jet engine usually results in lots of brown pants and a possible broken engine.
- Compressor stall in a turbo results in some funky sounding chatter from the intake system, either sounding like a squirrel or a pigeon depending on whether there is an air filter fitted and how long the intake piping, if any, is. It also doesn't result in damage, death or destruction.

:D
Click to expand...

Yes, the consequences may be a lot worse when
- your vehicle is a few thousand feet in the air
- has roughly 200 times the power of a starlet
- a few hundred degrees of heat

but whether it is a car or an aircraft, it is not good for the engine, causing it to:-
- heat up
- lose power
- possibly backfire
- put extra stress on the turbo
- force exhaust gasses the wrong way through the engine

i'm sure it will have little effect on a typical starlet, but it will be a lot more major on a 1500BHP skyline or similar!
 
A

Adam_Glanza

Member +
well yes as i stated earlier it would be worse for the engine running big boost
because it would have more strain on it but hey until weve got a 1500bhp skyline we will never no :p
 
You must log in or register to reply here.
Top