Engine rev flutter sound on upshifts

[Giblet]

That makes no sense.

Why do you only hear at the time the engine is near it's redline, and hasn't been shifted yet?

There is no reason any car, especially a race car, should start wobbling its tires at the top of each gear, before shifting.

I thought, likely wrongly, that since it was a new noise with V8, we were hearing harsher engine vibration from the higher rev range. This would help explain why it happens before shifting, and why it is longer sounding the higher the gear that it is in.

[alelanza]

That makes no sense.

Why do you only hear at the time the engine is near it's redline, and hasn't been shifted yet?

There is no reason any car, especially a race car, should start wobbling its tires at the top of each gear, before shifting.

I thought, likely wrongly, that since it was a new noise with V8, we were hearing harsher engine vibration from the higher rev range. This would help explain why it happens before shifting, and why it is longer sounding the higher the gear that it is in.

As I recall it, it took place post gear change, so you´re saying it was just prior to it?

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?

Perhaps that may be the right word. Basically the upshift tries to spin the wheels faster but can´t, so the tyre squishes just a bit back and forth, slightly varying the resisting torque in an undampened fashion. I know on normal cars you can feel it with a bit of spirited shifting, i assumed on an F1 having such a relatively smooth shift you can even hear it. But now the other guy says it happens pre shift, so i guess i´ll go watch abu dabhi again.

[Giblet]

Yeah it's right before, and most noticeable when the camera was facing the drivers face, with the air intake right above it.

The sound you are talking about is actually longer than the time it takes for the transmission to shift gears and already be on the power.

[CMSMJ1]

Bloody hell! What a random thread...

Is this not a resonance issue - purely audio pickup and nothing to do with gearboxes, wobbly tyres etc.

Could it simply be that the microphones are being buzzed at certain revs.

Also, the stutters were previously looked at on here and it was agreed generally that this was the transition from one beacon to another as the car moved around the circuits...

[Giblet]

These flutters are from years past and unrelated to the recent broadcast problems with transceivers in 2009.

It was only on the Ferrari if I remember, and I did suggest maybe it was a mic problem, but it doesn't seem like it. It seems like the engine goes from full song to slight misfiring. It is however engine note/intake related.

I think the tire wobble thing is rubbish though.

And yeah, what a random thread. Welcome to the world of being on an F1 site in the off season.

It is a curious sound, and if you are not interested, next random thread, right?

[tommylommykins]

My thoughts:

1) Tyres are universal between the teams. If Ferrari's tyres do it, then why shouldn't anybody else's tyres do it?

2) It is my opinion that tyres are too overdamped and underspringy for the flutter to be being produced there. (after all, you cannot ring a tyre like a bell.)

I would, however, be more happy in seeing the styres as being flexible enough to prevent the mass of the car immediately cancelling out the effect of this flutter, since you do not actually have to accelerate and decelerate the car with the engine with flexy tyres.

3) It is my opinion that the microphones are not malfunctioning (for no reason... it just doesn't look like that to me)

4) Metallic objects resonate quite well... Since so much force is applied to the transmission with modern superquick gear changes, can we not assume that this causes some part of the drivetrain to start oscillating?

[Giblet]

Here is what my mind thinks as possible, although probably not plausible.

1 - The size of the intake is the absolute smallest it needs to be to allow the engine enough air to operate at 18,000. Maybe atmospheric conditions "lower the bar", and the motor runs too rich. Unlikely.

2 - Since the motor is right near the RPM limit, maybe the engine was being told to run richer at the same RPM to increas power right before the shift. Ferrari still had their own ECU then so it could have been all sorts of different magic.

3 - As you said, resonance. The v8 is naturally an unbalanced beast compared to the v10, and it's vibrations become worse the higher it revs.

Just not the freakin tires wobbling

[autogyro]

Audible resonance in components within the 'zeroshift' and similar quick shift gear selector/dog clutch assemblies.

[Giblet]

Audible resonance in components within the 'zeroshift' and similar quick shift gear selector/dog clutch assemblies.

You going to finish your sentence or just leave us with that? It has nothing to do with transmission types.

Are you actually trying to shift this thread as well into a discussion about the merits of different types of gearboxes?

Blurting about dogs and selectors. I wish f1_eng would pipe up about this one.

[bazanaius]

Audible resonance in components within the 'zeroshift' and similar quick shift gear selector/dog clutch assemblies.

I ate a big red candle.

Life is like a box of chocolates.

other generic phrases containing words.

[autogyro]

Audible resonance in components within the 'zeroshift' and similar quick shift gear selector/dog clutch assemblies.

You going to finish your sentence or just leave us with that? It has nothing to do with transmission types.

Are you actually trying to shift this thread as well into a discussion about the merits of different types of gearboxes?

Blurting about dogs and selectors. I wish f1_eng would pipe up about this one.

Pipe away.
The observed peculiarity is stated as occurring at peak revs over a gear shift.
I am simply referring to the components in use at that specified time.

[F1_eng]

I'm not 100% sure exactly what you are refering to.

Probably the sound of un-burnt fuel in the exhaust when driver shifts and ignition is cut or retarded for a split second to reduce torque?
Listen to the cars at the track when they use pit-lane limiter, when its activated initially you get a lot of un-burnt fuel before the real limiter kicks in.

Some posts are getting very close to information I don't want to discuss, otherwise I would say some more.

Some very random theories.

[010010011010]

autogyro: why do yuo feel the need to put zeroshift in brackets all the time, that is its name right?

Probably the sound of un-burnt fuel in the exhaust when driver shifts and ignition is cut or retarded for a split second to reduce torque?
Listen to the cars at the track when they use pit-lane limiter, when its activated initially you get a lot of un-burnt fuel before the real limiter kicks in.

Ya i've heard that alright, makes sense too. thanks!

[autogyro]

I'm not 100% sure exactly what you are refering to.

Probably the sound of un-burnt fuel in the exhaust when driver shifts and ignition is cut or retarded for a split second to reduce torque?
Listen to the cars at the track when they use pit-lane limiter, when its activated initially you get a lot of un-burnt fuel before the real limiter kicks in.

Some posts are getting very close to information I don't want to discuss, otherwise I would say some more.

Some very random theories.

So you wont talk either. Know how you feel.
Very random theories.
Wasting fuel on the pit lane limiter, hmmm, some savings there.

[010010011010]

So you wont talk either. Know how you feel.

The difference is he hasnt looked for attenion by telling us about what he doesn't want to talk about at every available oppertunity.