squeaking noise from WRC cars

[MrJan]

I know Wiki isnt usuallly the most accurate of sorces but see the 'Wastegate chatter myth' section on here.. http://en.wikipedia.org/wiki/Wastegate

Back on the old, old forum Marcus Dodd did a fairly lengthy post about turbos that was quite interesting. Sadly now the archive has gone it's probably consigned to history

[Daniel]

I know Wiki isnt usuallly the most accurate of sorces but see the 'Wastegate chatter myth' section on here.. http://en.wikipedia.org/wiki/Wastegate

I found out the cause of this noise, dodgy window seals on frameless windows. Was driving to work today and the car started making the exact same noise as what is being described on this thread Scared the bejeezus out of me

[zerodegreec]

I thought it was stated that wrc cars dont have a waste gate...

[Zico]

I thought it was stated that wrc cars dont have a waste gate...

I think you must have the wastegate confused with a dump valve.

[OldF]

I think you must have the wastegate confused with a dump valve.

Yes, two different things.

http://www.turbobygarrett.com/turbob...o_tech103.html

Dump valve = blow of valve, BOV.

“Surge will decay once the turbo speed finally slows enough to reduce the boost and move the operating point back into the stable region. This situation is commonly addressed by using a Blow-Off Valves (BOV) or bypass valve. A BOV functions to vent intake pressure to atmosphere so that the mass flow ramps down smoothly, keeping the compressor out of surge. In the case of a recirculating bypass valve, the airflow is recirculated back to the compressor inlet.”

http://www.turbobygarrett.com/turbob...o_tech101.html

Wastegates

On the exhaust side, a Wastegates provides us a means to control the boost pressure of the engine. Some commercial diesel applications do not use a Wastegates at all. This type of system is called a free-floating turbocharger.

However, the vast majority of gasoline performance applications require a Wastegates. There are two (2) configurations of Wastegates, internal or external. Both internal and external Wastegates provide a means to bypass exhaust flow from the turbine wheel. Bypassing this energy (e.g. exhaust flow) reduces the power driving the turbine wheel to match the power required for a given boost level. Similar to the BOV, the Wastegates uses boost pressure and spring force to regulate the flow bypassing the turbine.

Internal Wastegates are built into the turbine housing and consist of a “flapper” valve, crank arm, rod end, and pneumatic actuator. It is important to connect this actuator only to boost pressure; i.e. it is not designed to handle vacuum and as such should not be referenced to an intake manifold.
Internal Wastegate

External Wastegates are added to the exhaust plumbing on the exhaust manifold or header. The advantage of external Wastegates is that the bypassed flow can be reintroduced into the exhaust stream further downstream of the turbine. This tends to
improve the turbine’s performance. On racing applications, this Wastegated exhaust flow can be vented directly to atmosphere.

[jparker]

Yes, two different things.

http://www.turbobygarrett.com/turbob...o_tech103.html

Dump valve = blow of valve, BOV.

“Surge will decay once the turbo speed finally slows enough to reduce the boost and move the operating point back into the stable region. This situation is commonly addressed by using a Blow-Off Valves (BOV) or bypass valve. A BOV functions to vent intake pressure to atmosphere so that the mass flow ramps down smoothly, keeping the compressor out of surge. In the case of a recirculating bypass valve, the airflow is recirculated back to the compressor inlet.”

http://www.turbobygarrett.com/turbob...o_tech101.html

Wastegates

On the exhaust side, a Wastegates provides us a means to control the boost pressure of the engine. Some commercial diesel applications do not use a Wastegates at all. This type of system is called a free-floating turbocharger.

However, the vast majority of gasoline performance applications require a Wastegates. There are two (2) configurations of Wastegates, internal or external. Both internal and external Wastegates provide a means to bypass exhaust flow from the turbine wheel. Bypassing this energy (e.g. exhaust flow) reduces the power driving the turbine wheel to match the power required for a given boost level. Similar to the BOV, the Wastegates uses boost pressure and spring force to regulate the flow bypassing the turbine.

Internal Wastegates are built into the turbine housing and consist of a “flapper” valve, crank arm, rod end, and pneumatic actuator. It is important to connect this actuator only to boost pressure; i.e. it is not designed to handle vacuum and as such should not be referenced to an intake manifold.
Internal Wastegate

External Wastegates are added to the exhaust plumbing on the exhaust manifold or header. The advantage of external Wastegates is that the bypassed flow can be reintroduced into the exhaust stream further downstream of the turbine. This tends to
improve the turbine’s performance. On racing applications, this Wastegated exhaust flow can be vented directly to atmosphere.

So, in plain words, the flow that spins the turbo is controlled by Wastegate, and the flow (compressed air) that turbo generates is controlled by BOV. Is that correct?
So, the noise is created by the compressed air going backwards (when throttle is lifted) through the compressor wheel. In other words neither the BOV or Wastegate are related to the noise. Is that correct?

[Gard]

The BOV/BPV and the wastegate also make noices. Different noises dependent of the setup. BOV are often made so they will sound the most. Many love the blowing/exhaling sound when shifting gears. This can also be heard when using BPV, especially with open air-filters. then you hear the air rushes back. WRC doesn't use wastegate, but the ALS will also make noises.

A turbo engine is like a small orchestra.

[Daniel]

The BOV/BPV and the wastegate also make noices. Different noises dependent of the setup. BOV are often made so they will sound the most. Many love the blowing/exhaling sound when shifting gears. This can also be heard when using BPV, especially with open air-filters. then you hear the air rushes back. WRC doesn't use wastegate, but the ALS will also make noises.

A turbo engine is like a small orchestra.

WRCars DO use a wastegate.....

[Gard]

WRCars DO use a wastegate.....

Call it what you like

[Daniel]

Call it what you like

There's no need to have an attitude! You said that WRCars don't use a wastegate when they do. Perhaps you yourself don't call it a wastegate but they do use a wastegate.....