Engine rev flutter sound on upshifts

[autogyro]

http://www.zeroshift.com/pdf/RcarN6V15_Zeroshift.pdf

Racecar Engineering article about it.

http://www.zeroshift.com/animation.html

Lovely animations about how it works.


This is NOT preseletion as used in the 30's using a billion clutches and epicyclic (I even had to read up on this just now as its so antiquated i'd never heard of it). This is the most likely current method of F1 seamless shift.

I have studied the zeroshift system in depth. I suggest you look carefully at it again and be certain of what you define as 'engaged'.
The Wilson gearbox uses a number of brake bands.
One band for each gear. The bands grip a drum, which is part of an epicyclic gear set. One band begins to disengage as another begins to engage, the time between one gear being engaged and driving and the next is a direct result of the slip between the band friction material and the drums. This 'wilsonshift' time is at least as good as the 'zeroshift' time comparing the delay between one gear transfering torque and the next. True, the Wilson is very heavy, old fashioned in every way but it is STILL as fast on shift overlap as any modern gearbox.

[xxChrisxx]

One band for each gear. The bands grip a drum, which is part of an epicyclic gear set. One band begins to disengage as another begins to engage, the time between one gear being engaged and driving and the next is a direct result of the slip between the band friction material and the drums. This 'wilsonshift' time is at least as good as the 'zeroshift' time comparing the delay between one gear transfering torque and the next. True, the Wilson is very heavy, old fashioned in every way but it is STILL as fast on shift overlap as any modern gearbox.

Didn't you read it... there is NO delay between torque output NOT A BEAN. The first gear is driving until the split second the second gear is driving.

The driving action OF the second gear disengages the first.

The fact that the selcetor linkages are connected in working contact to both 1st and 2nd gears AT THE SAME TIME means its in two gears at once. Only one gear is DRIVING at once, so by that you can argue it's not in two gears.

But that is a pretty weak argument based on sematics.

This is nothing like an old fashioned preselecter.That DID have a delay between outputs.

However 100% torque cannot be transmitted until the gear is fully engaged, as the inertia of dropping xthousand revs causes problems. This is where an advantage of a second clutch is vital, as you can smoothly elimitate that with some slip. However taken to the extreme that would lead to a 'pseudoCVT' between the finite ratios.



EDIT: And considering you have 'studied this in depth' how come you didn't instantly know what I was on about when I mentioned 'Zeroshift'. I mean the name is pretty distinct.

[autogyro]

One band for each gear. The bands grip a drum, which is part of an epicyclic gear set. One band begins to disengage as another begins to engage, the time between one gear being engaged and driving and the next is a direct result of the slip between the band friction material and the drums. This 'wilsonshift' time is at least as good as the 'zeroshift' time comparing the delay between one gear transfering torque and the next. True, the Wilson is very heavy, old fashioned in every way but it is STILL as fast on shift overlap as any modern gearbox.

Didn't you read it... there is NO delay between torque output NOT A BEAN. The first gear is driving until the split second the second gear is driving.

The driving action OF the second gear disengages the first.

The fact that the selcetor linkages are connected in working contact to both 1st and 2nd gears AT THE SAME TIME means its in two gears at once. Only one gear is DRIVING at once, so by that you can argue it's not in two gears.


But that is a pretty weak argument based on sematics.

This is nothing like an old fashioned preselecter.That DID have a delay between outputs.

It has nothing to do with semantics it is fact. NO stepped layshaft gearbox can have two gears engaged at the same time period.
Neither can an epicyclic band selected gearbox like the Wilson.
They are almost instant shift but can never be instant.

[xxChrisxx]

It has nothing to do with semantics it is fact. NO stepped layshaft gearbox can have two gears engaged at the same time period.
Neither can an epicyclic band selected gearbox like the Wilson.
They are almost instant shift but can never be instant.

What do you mean by engaged first of all?

If you mean DRIVING, then no they cant (two gears can't be driving at once but can be engaged at once). With a crash box engaged and driving are one and the same. With this gearbox you have to make the distinction between the two.

Like with the preselector box, that technically has 2 gears engaged at once, but only 1 is driving becuase the other is not connected via clutch. This has 2 selected AND coneected by a clutch, but only 1 driving.

If you mean engaged as in... in working contact. (Which is what the dictionary says the word means) Then it is in working contact with two gears at once.

Main Entry: en·gaged
Pronunciation: \in-ˈgājd, en-\
Function: adjective
Date: 1629

6 : being in gear : meshed

Main Entry: 1mesh
Pronunciation: \ˈmesh\
Function: noun
Etymology: Middle English, probably from Middle Dutch maesche; akin to Old High German masca mesh, Lithuanian mazgos knot
Date: 14th century

4 : working contact (as of the teeth of gears) <in mesh>

[autogyro]

It has nothing to do with semantics it is fact. NO stepped layshaft gearbox can have two gears engaged at the same time period.
Neither can an epicyclic band selected gearbox like the Wilson.
They are almost instant shift but can never be instant.

What do you mean by engaged first of all?

If you mean DRIVING, then no they cant (two gears can't be driving at once but can be engaged at once). With a crash box engaged and driving are one and the same. With this gearbox you have to make the distinction between the two.

Like with the preselector box, that technically has 2 gears engaged at once, but only 1 is driving becuase the other is not connected via clutch. This has 2 selected AND coneected by a clutch, but only 1 driving.

If you mean engaged as in... in working contact. (Which is what the dictionary says the word means) Then it is in working contact with two gears at once.

Main Entry: en·gaged
Pronunciation: \in-ˈgājd, en-\
Function: adjective
Date: 1629

6 : being in gear : meshed

Main Entry: 1mesh
Pronunciation: \ˈmesh\
Function: noun
Etymology: Middle English, probably from Middle Dutch maesche; akin to Old High German masca mesh, Lithuanian mazgos knot
Date: 14th century

4 : working contact (as of the teeth of gears) <in mesh>

I suggest you try to apply 'work. to one gear in mesh while another is in 'working' contact, there will not be much left.

[xxChrisxx]

I suggest you try to apply 'work. to one gear in mesh while another is in 'working' contact, there will not be much left.

In context that makes no sense what so ever.

Working contact means 'in contact' whilst in operation. It doesn't have to mean transmitting load.

You use some very odd definions of things (i'm sure that definions I use are probably different and seem weird to you), I think that's whats causing issues here. As you don't seem to have anything to say about the acutal technology, only the definitions used.


Jesus, we've managed to derail another thread.

[autogyro]

I suggest you try to apply 'work. to one gear in mesh while another is in 'working' contact, there will not be much left.

In context that makes no sense what so ever.

Working contact means 'in contact' whilst in operation. It doesn't have to mean transmitting load.

You use some very odd definions of things (i'm sure that definions I use are probably different and seem weird to you), I think that's whats causing issues here. As you don't seem to have anything to say about the acutal technology, only the definitions used.


Jesus, we've managed to derail another thread.

Yes, I feel an apology is due, I realize now that we are talking at cross purposes here.
Engaging gears is not driving through them.

[010010011010]

It could be a TV transmition problem. Like earlier on in the season when the used KERS it made the engine sound like it was jumping all over the place.

[alelanza]

I assumed it was some wobbliness courtesy of the suspension and tall profile tyres used.

[RH1300S]

Jesus, we've managed to derail another thread.

Hmmm - funny that

[Giblet]

It could be a TV transmition problem. Like earlier on in the season when the used KERS it made the engine sound like it was jumping all over the place.

No, not likely at all.

The engine note was at a specific place in the RPM range, right between shifts.

The glitch we had earlier was based in the relay of the signal from hop to hop, and happened to everyone, at a specific place on track, at any rpm range. The audio glitch was also accompanied by a video glitch, not present in the flutter.

The flutter was an actual product of the car, or possibly a sonic limitation of the mic.

If it was the transmission, it is no reason to go off on the merits / principles of transmissions designs. I understand there was a window talking about the flutter, and what makes it, but now it's just more tranny talk.

[Giblet]

I assumed it was some wobbliness courtesy of the suspension and tall profile tyres used.

Wat?

[alelanza]

I assumed it was some wobbliness courtesy of the suspension and tall profile tyres used.

Wat?

As the higher gear tries to speed up the tyres there´s some shaking or bouncing, not sure about the right english word, happening through the tyres and suspension. I think that shakiness is what we hear in those upshifts.

[autogyro]

I assumed it was some wobbliness courtesy of the suspension and tall profile tyres used.

Wat?

As the higher gear tries to speed up the tyres there´s some shaking or bouncing, not sure about the right english word, happening through the tyres and suspension. I think that shakiness is what we hear in those upshifts.

Probably caused by 'zeroshifting'.

[ISLAMATRON]

I assumed it was some wobbliness courtesy of the suspension and tall profile tyres used.

Wat?

As the higher gear tries to speed up the tyres there´s some shaking or bouncing, not sure about the right english word, happening through the tyres and suspension. I think that shakiness is what we hear in those upshifts.

Tire shake is what the drag racing guys call it but I doubt F1 cars have the torque to enduce that in the higher gears.

Or maybe you are reffering to wheel hop?