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Off Throttle Trick Comes Back Again


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#1 Mc_Silver

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Posted 27 October 2012 - 22:07

Posted Image

In India Red Bull have again modified the RB8's bodywork around the exhaust exits. This drawing highlights the resonance chamber (red arrows) used to create gas pressure when the engine is on throttle, to be released out through the exhausts (dotted yellow line) when it goes off throttle.


http://www.formula1....2/880/1018.html

It looks like genius Newey found a way to bring off throttle in play yet again :drunk:

Edited by Mc_Silver, 27 October 2012 - 22:22.


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#2 jrg19

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Posted 27 October 2012 - 22:17

I think Ferrari have something like this too.

#3 Ross Stonefeld

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Posted 27 October 2012 - 22:17

Newey develops and designs everything on the car. The only reason they have other designers and engineers back at Renault is so things look 'normal'.

#4 scheivlak

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Posted 27 October 2012 - 22:18

It would be nice if you gave us the source of that quote :)


#5 Mc_Silver

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Posted 27 October 2012 - 22:23

It would be nice if you gave us the source of that quote :)


Done :up:

#6 MirNyet

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Posted 27 October 2012 - 22:24

I did notice some odd sounding exhausts during Quali today... This is beyond boring - if something is banned - its banned... Get the exhaust exits behind the rear line of the car and be done with it...



#7 Mc_Silver

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Posted 27 October 2012 - 22:26

I did notice some odd sounding exhausts during Quali today... This is beyond boring - if something is banned - its banned... Get the exhaust exits behind the rear line of the car and be done with it...


I'm sure Newey would find another way to achieve his ambitions :lol:

#8 MirNyet

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Posted 27 October 2012 - 22:29

I'm sure Newey would find another way to achieve his ambitions :lol:


I wouldn't mind - at least it would be within the rules - not within a heavily bent reading of the letter of the rules. As I said - its gotten beyond old and is very boring. One trick pony anyone?

#9 as65p

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Posted 27 October 2012 - 22:34

I did notice some odd sounding exhausts during Quali today... This is beyond boring - if something is banned - its banned... Get the exhaust exits behind the rear line of the car and be done with it...


I'm saying that for years now.

I wouldn't mind - at least it would be within the rules - not within a heavily bent reading of the letter of the rules. As I said - its gotten beyond old and is very boring. One trick pony anyone?


Now that sounds like sour grapes, sorry. I'm pretty sure they all would like to be able and use that "one trick", but apparently Newey is simply always one step ahead, kudos to him. The others wouldn't mind raping the "spirit of the rules" too, if only they knew how.

#10 plumtree

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Posted 27 October 2012 - 22:34

Here you go:

'One area of Ferraris exhaust development that has recently been exposed is the exhaust chamber. These devices have been rumoured for many months. Most of the rumours attributed to Mercedes engined teams, although no evidence has appeared of the system on any of their three teams cars. As reported by Giorgio Piola at the Abu Dhabi race, Ferrari had this system in place for the Grand Prix and the system remained fitted for at least part of the test. What at first appears to be another exhaust outlet joined to the secondary exhaust pipe, is in fact a closed ended pipe. This picture of the exhaust removed from the car (http://www.f1talks.p...estow/?pid=7210 via F1talks.plSutton Images), shows the large extension, which acts as a pressure accumulator when the exhaust is blowing. Then when the driver is off the throttle the pressure built up in the chamber is release, which smoothes the blown diffuser effect between full and partclosed throttle.'

http://scarbsf1.com/...-2012-exhausts/

I was starting to think my memory was playing tricks, but they did have it last year. Not sure that anyone had worked out what it was for then (nor that they're 100% sure they have now), which explains why it's hard to find. The theory at the time appears to have been that they were to smooth the transition from on to off throttle levels or downforce provided by the EBD, but given the tiny amount of gas they hold, and the low pressure it would probably exit at, that never seemed the most likely explanation. The most convincing things I've heard are that it's to control vibrations thereby prolonging exhaust life (reducing the likelihood of cracking), or that it can be used to tune torque delivery. It must be good for something, anyway.

Of course, once a few people have spent a few months researching what the funny pipe is called, and speculating on what it might be for, 'Red Bull debuts Helmholz Resonator!' is a ready made story for lazy journalists which fits with the current 'Red Bull as innovators' agenda and makes them look better informed than they are. It's a win-win for them.

And now it became 'RBR bending the rules again!' story.


A couple of posts from the RB8 thread,

http://forums.autosp...w...t&p=5979835
http://forums.autosp...w...t&p=5979855

Edited by plumtree, 27 October 2012 - 22:37.


#11 stevesingo

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Posted 27 October 2012 - 22:35

That 300mmx60mm (guess) tube will contain about 1.7 litres of gas. Working on the understanding that 4 stroke engines don't like pressure in the exhaust (back pressure), this chamber will not be under a constant pressure. Therefore the mass of gas within the chamber will not be much more than the volume X gas density @ atmospheric pressure. Therefore I don't see how much benefit to aerodynamics this could have.

I suspect the reason for having a Helmholtz chamber is to try to regain some of the lost engine power that results from the compromised (from an engine point of view) exhaust openings. The engine people would probably prefer a different exhaust length for best engine performance than the length dictated to them by the aerodynamics. In order to regain some of the tuned length benefits, a helmholtz chamber is added to add effective length to the exhaust system.

Steve



#12 STRFerrari4Ever

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Posted 27 October 2012 - 22:36

I wouldn't mind - at least it would be within the rules - not within a heavily bent reading of the letter of the rules. As I said - its gotten beyond old and is very boring. One trick pony anyone?

Change your recipe for success for what, the "spirit" of the regulations? If it worked before find a way to make it work again and kudos to Newey, engineers in Milton Keynes and the guys at Renault for coming up with a new solution that works a treat again.

#13 RockyRaccoon68

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Posted 27 October 2012 - 22:36

Ferrari have had this since 2011, it's not cheating or even exploiting a loophole. The big problem with the new exhaust rules is that they still allowed the teams to place them in an area where the diffuser could be blown. I have no idea why they didn't make it more simple, I mean surely all the money the teams have spent on exhaust solutions this year has been more than if they had just kept the low down EBDs?

#14 ThomFi

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Posted 27 October 2012 - 22:44

And now it became 'RBR bending the rules again!' story.


A couple of posts from the RB8 thread,

http://forums.autosp...w...t&p=5979835
http://forums.autosp...w...t&p=5979855




This, it's the Helmholtz resonator, Red bull is using it since the GP of Great Britain, Ferrari even since last year.
Obviously, Red Bull has optimized it for this race, but it's hardly a new invention.


Red Bull adopts Helmholtz exhaust chamber

Posted Image

Edited by ThomFi, 27 October 2012 - 22:49.


#15 Dolph

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Posted 27 October 2012 - 22:52

Newey develops and designs everything on the car. The only reason they have other designers and engineers back at Renault is so things look 'normal'.


You worded really well what I was just going to say.

#16 stevesingo

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Posted 27 October 2012 - 22:56

STOP STOP STOP.

A 2litre MAX cylinder of gas at ambient pressure will not blow a diffuser.

An F1 engine consumes 28080 Litres of air per minuet at 18000rpm, or 468lt/sec and exhausts even more gas than that of air consumed. Even if the 2lt container was at 10bar pressure (which it most certainly is not), it would only contain the equivalent of 20lt of gas. Or, 20/(468)=0.42secs of exhaust blowing. NOT. But more like the pressure is 1Bar above ambient, so 0.042sec of blowing.


edited: 468lt/sec not lt/min

Edited by stevesingo, 27 October 2012 - 23:16.


#17 ClubmanGT

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Posted 27 October 2012 - 22:59

STOP STOP STOP.

A 2litre MAX cylinder of gas at ambient pressure will not blow a diffuser.

An F1 engine consumes 28080 Litres of air per minuet at 18000rpm, or 468lt/min and exhausts even more gas than that of air consumed. Even if the 2lt container was at 10bar pressure (which it most certainly is not), it would only contain the equivalent of 20lt of gas. Or, 20/(468)=0.42secs of exhaust blowing. NOT. But more like the pressure is 1Bar above ambient, so 0.042sec of blowing.


You also have to remember they way that force being released changes the pitch of the car or the channels of air. If that 0.042 seconds takes 0.42 to completely dissipate around the back of the car, then that's the advantage gained.

#18 stevesingo

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Posted 27 October 2012 - 23:19

You also have to remember they way that force being released changes the pitch of the car or the channels of air. If that 0.042 seconds takes 0.42 to completely dissipate around the back of the car, then that's the advantage gained.


Really?

If that gas is dissipated over 0.42 sec, then the pressure release would be so slow as to be akin to letting the air out of a balloon. Not even measurable in the scheme of F1 aerodynamics. See post 11 for a more likely explanation.



#19 Jejking

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Posted 27 October 2012 - 23:53

Sorry to barge in like this, but this is interesting. During last race we've been onboard with Hamilton for a couple of times and unlike normal his engine was creaking a LOT at the exit of some corners, when he was putting the hammer down. It really sounded like a traction control lite to me, anybody else who withnessed the same thing?

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#20 ClubmanGT

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Posted 28 October 2012 - 00:00

If that gas is dissipated over 0.42 sec, then the pressure release would be so slow as to be akin to letting the air out of a balloon. Not even measurable in the scheme of F1 aerodynamics. See post 11 for a more likely explanation.


Oh I agree, more wanting to point out that aero impact of pressure changes is dynamic until the same pressure over the area in question has fully returned to normal.

#21 Wuzak

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Posted 28 October 2012 - 00:07

I would think that a Helmholz resonator would be against the clause in the rules forbidding variable exhausts.

#22 dav115

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Posted 28 October 2012 - 00:34

Sorry to barge in like this, but this is interesting. During last race we've been onboard with Hamilton for a couple of times and unlike normal his engine was creaking a LOT at the exit of some corners, when he was putting the hammer down. It really sounded like a traction control lite to me, anybody else who withnessed the same thing?

I heard this too for the first time at Korea.
Really blatant at 39 secs for example.
Not a clue what is is though, can't see it being related to the Helmholtz resonator.

#23 packapoo

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Posted 28 October 2012 - 06:25

I wouldn't mind - at least it would be within the rules - not within a heavily bent reading of the letter of the rules. As I said - its gotten beyond old and is very boring. One trick pony anyone?


Mug.
It's innovation! Not bending rules.

Some people can think originally, don't have to be lead by their nose to the rulebook.


#24 H2H

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Posted 28 October 2012 - 09:28


The chamber is old news as is the current engine mapping. Obviously there is a lot of development and finetuning going on working within a very strict rule set.

#25 Ali_G

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Posted 28 October 2012 - 10:33

Newey develops and designs everything on the car. The only reason they have other designers and engineers back at Renault is so things look 'normal'.


:rotfl:

#26 FPV GTHO

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Posted 28 October 2012 - 10:33

That 300mmx60mm (guess) tube will contain about 1.7 litres of gas. Working on the understanding that 4 stroke engines don't like pressure in the exhaust (back pressure), this chamber will not be under a constant pressure. Therefore the mass of gas within the chamber will not be much more than the volume X gas density @ atmospheric pressure. Therefore I don't see how much benefit to aerodynamics this could have.

I suspect the reason for having a Helmholtz chamber is to try to regain some of the lost engine power that results from the compromised (from an engine point of view) exhaust openings. The engine people would probably prefer a different exhaust length for best engine performance than the length dictated to them by the aerodynamics. In order to regain some of the tuned length benefits, a helmholtz chamber is added to add effective length to the exhaust system.

Steve


Typically a shorter exhaust will aid power though, the longer exhaust will rob some top end power and provide more low end power.

#27 Chomsky

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Posted 28 October 2012 - 17:14

If they didn't need to down-shift sequentially they could easily get around the ban on off-throttle blowing by putting the car in neutral and then telling the driver to stay on the throttle while braking at the same time?

#28 TheWilliamzer

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Posted 28 October 2012 - 17:24

The FIA will hire a sniper for Newey.

#29 Jejking

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Posted 28 October 2012 - 17:37

I heard this too for the first time at Korea.
Really blatant at 39 secs for example.
Not a clue what is is though, can't see it being related to the Helmholtz resonator.

I thought I was going nuts but I wasn't the only one who was wondering about that! Maybe an idea for a single F1technical-like thread?

#30 TheWilliamzer

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Posted 28 October 2012 - 17:40

Sorry to barge in like this, but this is interesting. During last race we've been onboard with Hamilton for a couple of times and unlike normal his engine was creaking a LOT at the exit of some corners, when he was putting the hammer down. It really sounded like a traction control lite to me, anybody else who withnessed the same thing?



I heard this too for the first time at Korea.
Really blatant at 39 secs for example.
Not a clue what is is though, can't see it being related to the Helmholtz resonator.



I thought I was going nuts but I wasn't the only one who was wondering about that! Maybe an idea for a single F1technical-like thread?


Hamilton had a rear anti-roll bar failure. the sound is a sign of damage.

#31 Torsion

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Posted 28 October 2012 - 17:40

I think this is to smooth the on-throttle / off-throttle blowing effect, rather than to work as an off-throttle blowing mechanism. With the chamber in place, as soon as the driver goes off throttle, the car wouldn't loose the blown effect / df immediately, rather, due to the pressure in the chamber it will be a more measured/gradual reduction in the blowing. So in my view it is in place to make sure the car is more predictable.


Edited by Torsion, 28 October 2012 - 17:41.


#32 robybobey

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Posted 28 October 2012 - 18:20

Hamilton had a rear anti-roll bar failure. the sound is a sign of damage.


The failure only happened at the end of the first stint? Not in qually....?

#33 TheWilliamzer

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Posted 28 October 2012 - 18:28

The failure only happened at the end of the first stint? Not in qually....?

I watched the onboard race! the onboard quali I have no idea.

#34 robybobey

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Posted 28 October 2012 - 18:29

I watched the onboard race! the onboard quali I have no idea.


Ahh, I thought you were referring to the video you quoted.