Red Bull RB11 Renault

[XRayF1]

Guys,

Has anyone noticed this distinct high pitched (even slightly metallic) sound made by the turbine while the RB11 enters a turn?
Comparing the sound of the Renault PU with the others, I believe this to be unique to them.

https://www.youtube.com/watch?v=-soYq_ZbIzY
At around 2:30, while the RB11 is entering the corner as well as at the apex of it.
When a Merc PU'd car (and I believe I also hear it from the Ferraris) enters a corner, it gives some staccato like downshifting sound followed by a simple (and perhaps even expected?) roar while stepping on the throttle.
You do not hear such turbine sound.
(Just for completeness, this turbine sound is also heard from the Honda PU, but as the PU is not yet up to par with the others, I have left it out)

Question arises - why is the Renault PU configured like that?
High turbine speeds equals high pitched sound and keeps the power up, but why do we hear it only at the Renault PU that distinctively?
If keeping the power up, isn't this counter productive for fuel consumption? Because the energy for turning the turbine must come from somewhere ...

Would appreciate your thoughts.

[djos]

Interesting question, do Renault run a smaller higher rpm turbo compared to the other's I wonder?

[atlantis]

Could it be due to different energy harvesting strategies?
Also: could it be related to different anti-lag (spinning the turbo inside the turn for optimal power exiting turns) strategies?

[henra]

Has anyone noticed this distinct high pitched (even slightly metallic) sound made by the turbine while the RB11 enters a turn?
Comparing the sound of the Renault PU with the others, I believe this to be unique to them.

Hmm, indeed. Normally a whistling Turbo is not really a good sign. That ususally happens when the geometry of the vanes/ turbine blades doesn't properly match to the airflow through the turbo.
Possibly still sub- optimum synchronisation with MGU-H?

[PhillipM]

I would imagine so, hence the Honda also having the note as it wasn't running anywhere near full ERS system modes.

[hixaxon]

Has anyone noticed this distinct high pitched (even slightly metallic) sound made by the turbine while the RB11 enters a turn?
Comparing the sound of the Renault PU with the others, I believe this to be unique to them.

Hmm, indeed. Normally a whistling Turbo is not really a good sign. That ususally happens when the geometry of the vanes/ turbine blades doesn't properly match to the airflow through the turbo.
Possibly still sub- optimum synchronisation with MGU-H?

Hi guys, my first response here (a lot of reading done). Thank you.

Interesting thoughts.

I'm not a mechanical or aerodynamic engineer, but I have a solid hearing and audio equipment.

First of all, the sound quality and recording equipment is really poor, check the spectrum. There is a lot of artifacts and compression (YT didn't helped at all). Frequency spectrum cuts off way before 20 kHz. On the other hand, turbo on the Renault PU is much clearly visible in the spectrum than other PUs. In other words, It is emitting more sound energy over all of the PUs rpm range.

I don't think this sample is that much relevant, but if I had to guess, I would say it is so because of different materials and exhaust manifold configuration. I wouldn't think that is a problem.

Secondly, we would need a consistent record with better quality on the same spot on the track to really differentiate things here.

Just my point of view.

[Hobbs04]

Looking back at my Austin gp videos on my cellphone the rb10 made that noise , along with Toro rosso... The sound is most heard under harvesting IMHO. these cars get really quiet under braking so it could just be audible at that point.

[gandharva]

Diffusor + air outlet.

[mikeerfol]

https://twitter.com/ScarbsF1/status/565827837727621120

[XRayF1]

Interesting question, do Renault run a smaller higher rpm turbo compared to the others I wonder?

What benefit would a smaller turbo give them?
Isn't it more complex than a slightly larger one?
Material - smaller dimensions mean higher RPMs of the turbine thus needing more solid materials e.g. for the shaft?
Coolers - higher RPMs mean higher temperature - larger coolers, which are usually a bad idea on an F1 car

On the other side a smaller turbine does give them a better turbo response, right?
Allowing them to harvest the energy earlier, or more efficiently?

Would this be a possible explanation?

[djos]

Honestly I don't know, less energy required to keep it spooled up perhaps?

[AlainProst]

Do you know Willard and his "custer channel wing " concept ". It was a system designed to reuse exhaust gases to increase the bearing of the wing. It's this system that teams want to apply with the monkey seat placed above the exhausts. The perfect example was the Lotus E21 monkey seat isn't it ?

Excuse me for my english but I come from France but French forums are not as detailed and rigorous than here...

[PlatinumZealot]

Do you know Willard and his "custer channel wing " concept ". It was a system designed to reuse exhaust gases to increase the bearing of the wing. It's this system that teams want to apply with the monkey seat placed above the exhausts. The perfect example was the Lotus E21 monkey seat isn't it ?

Excuse me for my english but I come from France but French forums are not as detailed and rigorous than here...

Hey, Alain. How are things over at Renault? Nice that a four time world champion such as yourself would visit this humble cove. The other four time champion is not as accessible as yourself.

[AlainProst]

Do you know Willard and his "custer channel wing " concept ". It was a system designed to reuse exhaust gases to increase the bearing of the wing. It's this system that teams want to apply with the monkey seat placed above the exhausts. The perfect example was the Lotus E21 monkey seat isn't it ?

Excuse me for my english but I come from France but French forums are not as detailed and rigorous than here...

Hey, Alain. How are things over at Renault? Nice that a four time world champion such as yourself would visit this humble cove. The other four time champion is not as accessible as yourself.

Yeah I'm a four time champion ! I hope Renault will be better than last year but I think the classification will be the same than 2014, except for Lotus and Force India. For the RB11, I've some doubts they will reduce the gap with Mercedes because Cyril Abiteboul says that the gap betwenn the Mercedes PU and the Renault was about 60 hp last year and for 2015, it's 30 hp whereas the cooling requirements are unchanged says Newey (but all cooling components are redesigned for thinnest sidepods). So I think Mercedes is currently untouchable.

[hamilton#1]

https://www.youtube.com/watch?v=OJ17ANIrXNA