Fastest gearchanges were pre-1990's

[machin]

There is absolutely no reason mechanicaly for a manual gear shift to take longer to disengage and engage gears than any other form of gear shift.

Yes, We all know that.... but you originally said that a person can do it quicker. We're still waiting for the proof....?

EDIT: Not only that, but you said a manual pre 1990's gearbox is quicker than the current pneumatic shifts which use the "seamless" arrangement they employed today... proof please.

[flynfrog]

If this modulation is before the actual shift overlap and or after it, which is nearly always the case in road semi and auto layshaft systems, then this modulation has to be added to the time taken for the over all shift because it is a reduction in torque transfer from the engine to the road wheels.

maybe we don't understand your terminology here. how is it that a human would not have to do the same here. a rev match a throttle blip a feather of the clutch. Unless you are simply slamming gears both systems need to do this.


Where is the proof to your claim or is this a normal autogyro thread.

[hardingfv32]

You both are failing to acknowledge that autogyro has stated that the limit to the speed of a shift is the 'rotational moment of inertia' of the components, not the actual movement of the shift mechanisms.

There is nothing to preclude a human from making a shift that is just as fast as a machine. It will be a rare event requiring skill, luck and a good measure of recklessness. It will in all most likely not be recorded on any data system or if it is, not available to any search that we can make.

So, autogyro's theory is valid but not easily demonstrated.

Brian

[Richard]

There is nothing to preclude a human from making a shift that is just as fast as a machine. It will be a rare event requiring skill, luck and a good measure of recklessness. It will in all most likely not be recorded on any data system or if it is, not available to any search that we can make.

We do have evidence that it is possible and not rare. See Machin's post above, and also I posted a quote for manual shifts at 80ms.

[Tim.Wright]

There is nothing to preclude a human from making a shift that is just as fast as a machine.

I would disagree on the basis that a high pressure hydraulic system has more mechanical power to impart onto the shift mechanism than a human arm does so it will accelerate the moving parts faster.

The inertias of the moving parts are a working against the shifting force but they are in no way a limiting factor. More shifting power will give ou a faster response.

Unfortunately I dont have a feel for the power available in the hydraulics or a human hand though Id imagine a human could output several hundered watts and a hydraulic shifter could use several kilowatts.

Tim

[hardingfv32]

The inertias of the moving parts are a working against the shifting force but they are in no way a limiting factor. More shifting power will give ou a faster response.

I would agree.

My statement was not accurate enough. It is the 'rotational moment of inertia' of the 'rotating' components that is claimed by autogyro to be the limiting factor in the speed of a shift.

Brian

[munks]

There is nothing to preclude a human from making a shift that is just as fast as a machine.

I would disagree on the basis that a high pressure hydraulic system has more mechanical power to impart onto the shift mechanism than a human arm does so it will accelerate the moving parts faster.

I tried to argue this on a different board in a slightly different manner (arguing that a human arm couldn't accelerate the gear lever faster than X G's), but someone pointed out to me that a human doesn't necessarily have to accelerate from zero. It's conceivable that I could swing my arm across the cockpit and manage to knock the shifter from one gear to another quite quickly.

Of course you could easily rig up a mechanical arm to swing and perform this same haphazard shifting technique, just as quickly and far more consistently. So we are STILL waiting for the proof from autogyro or anybody else to show that a human can do it *quicker*.

[machin]

You both are failing to acknowledge that autogyro has stated that the limit to the speed of a shift is the 'rotational moment of inertia' of the components, not the actual movement of the shift mechanisms.

There is nothing to preclude a human from making a shift that is just as fast as a machine. It will be a rare event requiring skill, luck and a good measure of recklessness.

So, autogyro's theory is valid but not easily demonstrated.

But I think you're missing the point that Autogyro claimed that manual pre-1990's geaboxes were FASTER than they are now, not just merely "as fast" (see topic title)... If that were the case why doesn't a team just take a pre-1990's gearbox and attach a pneumatic actuator to it? Where's the additional rotational inertia in that arrangement?

[RH1300S]

The statement may or may not be true - several pages of debate haven't agreed on that one yet.

If the thread title was something along the lines of 'manual racing gearboxes can change gear must faster than we think when the driver is skilled enough' then there would be general agreement.

The danger in a statment like the thread title is that the debate centres on a narrow definition. It doesn't even seem to lead anywhere - like for example the question - is a manual gearbox better in a race car than a 'button/paddle' gearbox.

I do follow some of Autogyro's thinking in that a top driver can change gear very quickly indeed with a racing 'box. I remember Senna bemoaning the fact that that particular advantage was denied him - after all not everyone could change gear as fast as Senna and certainly not for the whole race.

Which probably brings us back to why the 'button/paddle' shifts? Surely if you look at an entire race weekend and then a season, whilst a manual gearchange MIGHT be fast for some of the time. Over a weekend/season the 'button/paddle' is surely the better system, not just for reliable and fast gearchanges, but for space saved in the cockpit (aero benefit), the freedom to keep the drivers hands on the steering wheel to do other useful work. Looking at a race car as a system, surely mechanical is better than human.

[machin]

RH1300S, I agree with you; I'd even go so far as to say that a title such as "A skilled driver can change a normal sequential gearbox as quick as a pneumatic/hydraulic actuator" would be acceptable. However, as you say, the main advantage is that a semi-auto system could do those changes day-in, day-out.

I have to say though, I do not agree with Auto's claim that a pre 1990's gearbox (manual or pneumatic/hydraulic) will be as quick as today's gearboxes; the seamless shift technology is the deciding factor:-

Rather than one barrel to move the selector forks the seamless gearbox has two, one operating the odd ratios and the other operating the evens. With one gear still engaged the other barrel is rotated to engage the next ratio. As the new gear's dogs meet, they pick up the drive, taking the load off the previous ratio. However, before the unloaded gear's dogs can swing around and engage with their opposite faces, their barrel is rotated to snatch them out of engagement

With the pre-1990's gearboxes having only one selector barrel it doesn't matter if you have the best driver in the world; the selector barrel is designed such that only one gear can be engaged at any one time, with a margin,(if it weren't then I doubt any car would get to the end of a race). The same is not true of the seamless shift; it is technically feasible that two gears be engaged at once, but the control system ensures this doesn't quite happen.

Because the F1 seamless shift relies on electronics to control the selector barrels independantly I don't believe you could backwardly convert an F1 seamless shift to be purely manually actuated, however, XTRAc have developed a pure mechanical version of the seamless shift called IGS. This uses springs and ratchets to pull the first gear out of engagement rather than a sophisticated hydraulic control system. I believe that this means it could easily be operated using a manual selector lever, and we could then say that "A driver can change a seamless shift gearbox as quick as a pneumatic/hydraulic actuator"

Another interesting quote from the same RE article:-

But what about the problem of the inevitable torque spike when the inertia of a fast spinning engine is slammed into a set of dogs connected to some sticky racing tyres? Phil Roper, principle engineer, explains that it has not proved to be a problem. The total variation of torque [with the seamless shift] is actually smaller and can easily be absorbed by the wind up in the drivetrain. The drivers say it is very smooth and actually unsettles the car less in corners

[bigpat]

Having actually raced a proper RACING H pattern gearbox, having worked with sequential gearbox single seaters, and knowing a little of F1 technology, I can tell you a 80's or 90's box is NOT quicker than today.

Those boxes contained BIG gears, with a lot of rotational inertia, compared to the tiny gears of today. Also, flat changing is quick, but the dog rings still have to slide the 10-200 mm across to engage. With human effort, and play in linkages etc, 0.2 sec for a completed shift. A modern 'non-seamless' box can do it 0.05 sec. No arguement.

Also, with the H pattern boxes, you always lose time going diagonally across the gate.

With a conventional box, you always lose drive through the shift, even flat changing. I change clutchless in a racecar, and only lift of say 15-20% throttle on an up change ( flat shifting is reckless, especially if you want reliability), but, there is a reduction of torque to the back wheels, compared to full throttle. A seamless shift sees no perceptible loss in torque measured at the back wheels.

Sequential and seamless shifts were NOT crested to eliminate driver input of skill, as I believe gerachanging speed/skill is always over-rated by people( most of whom have never driven a race car). No, these systems were introduced (as with all things)because they are quicker in laptime, full stop.

It is a fact that an F1 seamless shift box reduced laptimes by up to 0.3 sec per lap over a conventional box. That is an average of 15-18 secs over a race, which is massive.

Personally I think today's drivers have it tougher. No they don't shift gears, ( but the cars are quicker which means more physical loading on the body)but they must have presence of mind to use all the buttons and knobs on the wheels, and activate all the systems on a modern GP car, at full speed, listening to someone in your ear. Also, tactics are much better understood today, with everything calculated down to the second, where they expect the edriver to punch out times like a machine.

Back in the day, it was more man vs man, and generally laptimes varied a little more. The sport wasn't as precise as it is now...

[autogyro]

Having actually raced a proper RACING H pattern gearbox, having worked with sequential gearbox single seaters, and knowing a little of F1 technology, I can tell you a 80's or 90's box is NOT quicker than today.

I have used repaired and developed improved performance gearbox systems for over 40 years. Re read the post heading, I made no direct comparison to F1 technology.
The jury is out on when the fastest F1 shifts were in use. It is not the point.

Those boxes contained BIG gears, with a lot of rotational inertia, compared to the tiny gears of today. Also, flat changing is quick, but the dog rings still have to slide the 10-200 mm across to engage. With human effort, and play in linkages etc, 0.2 sec for a completed shift. A modern 'non-seamless' box can do it 0.05 sec. No arguement.

There were plenty of geartrains in use with similar gear weight to todays F1 gear sets. Your shift timing is 'wrong' I have timed manual gearshifts in dog ringed boxes at 0.08 ms. A grandmother in a shopping car could meet your figures of 0.2 sec.

Also, with the H pattern boxes, you always lose time going diagonally across the gate.

True but it is a loss of 0,02 ms at the worst for a skilled driver.
In anycase manual gearshift mechanisms are not limited to H pattern.

With a conventional box, you always lose drive through the shift, even flat changing. I change clutchless in a racecar, and only lift of say 15-20% throttle on an up change ( flat shifting is reckless, especially if you want reliability), but, there is a reduction of torque to the back wheels, compared to full throttle. A seamless shift sees no perceptible loss in torque measured at the back wheels.

There is NO potential difference in the mechanical shifting mechanism chosen at the hub for either manual or so called seamless shifting, it is the method of triggering the shift that varies and the design of the gear lever geometry.
In fact the 'seamless hub mechanisms are more complex and work in more than one direction and are potentially slower than a strait dog hub.

The seamless shift systems use engine cuts and clutch disengagement to 'smooth' the shift actuation. Where this modulation occurs other than at shift overlap it reduces the efficient transfer of torque through the system and increase the time taken to transfer torque. The shift speed is not decreased by modulation because the limit to shift speed is the rotational inertia of the input components, not the shifting mechanism.

Sequential and seamless shifts were NOT created to eliminate driver input of skill, as I believe gerachanging speed/skill is always over-rated by people( most of whom have never driven a race car). No, these systems were introduced (as with all things)because they are quicker in laptime, full stop.

Sequential shifting was a sensible improvement to manual gearshifting. I advised Garry Anderson on this very point for the first Jordans, where they used a 7 speed manual sequential geartrain. Seamless is simply a method to soften and control gearshifts sufficiently to allow a fast gearshift using automatic systems. In F1 cars are held to the ground with huge downforce and therefore do not suffer the unbalance the use of a close to 'sledgehammer' shift would otherwise apply to the car. Without huge downforce these gearboxes would make the cars undrivable.

It is a fact that an F1 seamless shift box reduced laptimes by up to 0.3 sec per lap over a conventional box. That is an average of 15-18 secs over a race, which is massive.

You have no data to confirm this and it is simply untrue. The shift overlap and engagement spike may be measures at between 0.05 and 0.08 ms but this does not take into account any powertrain modulation that effects the TOTAL time taken for the change between fixed ratios.

Personally I think today's drivers have it tougher. No they don't shift gears, ( but the cars are quicker which means more physical loading on the body)but they must have presence of mind to use all the buttons and knobs on the wheels, and activate all the systems on a modern GP car, at full speed, listening to someone in your ear. Also, tactics are much better understood today, with everything calculated down to the second, where they expect the edriver to punch out times like a machine.

Back in the day, it was more man vs man, and generally laptimes varied a little more. The sport wasn't as precise as it is now...

[autogyro]

I think the debate on this thread can be of use to many involved in performance vehicles.
I thank everyone who has contributed.

I think it is important to again state the primary limiting factor to gearshift time when using any type of layshaft stepped gearbox.

It does not matter if the gearbox is sequential, seamless, manual or any other type of shift system.

It is the ability of the geartrain to reduce the rotating speed of the engine and input components within an acceptable time frame, (shift overlap).

[autogyro]

But what about the problem of the inevitable torque spike when the inertia of a fast spinning engine is slammed into a set of dogs connected to some sticky racing tyres? Phil Roper, principle engineer, explains that it has not proved to be a problem. The total variation of torque [with the seamless shift] is actually smaller and can easily be absorbed by the wind up in the drivetrain. The drivers say it is very smooth and actually unsettles the car less in corners

The only way the 'variation of torque' can be 'actually smaller', is if the torque from the engine is reduced by modulating the shift.

This reduces the efficient transfer of torque to the rear wheels.

[autogyro]

The statement may or may not be true - several pages of debate haven't agreed on that one yet.

If the thread title was something along the lines of 'manual racing gearboxes can change gear must faster than we think when the driver is skilled enough' then there would be general agreement.

The danger in a statment like the thread title is that the debate centres on a narrow definition. It doesn't even seem to lead anywhere - like for example the question - is a manual gearbox better in a race car than a 'button/paddle' gearbox.

I do follow some of Autogyro's thinking in that a top driver can change gear very quickly indeed with a racing 'box. I remember Senna bemoaning the fact that that particular advantage was denied him - after all not everyone could change gear as fast as Senna and certainly not for the whole race.

Which probably brings us back to why the 'button/paddle' shifts? Surely if you look at an entire race weekend and then a season, whilst a manual gearchange MIGHT be fast for some of the time. Over a weekend/season the 'button/paddle' is surely the better system, not just for reliable and fast gearchanges, but for space saved in the cockpit (aero benefit), the freedom to keep the drivers hands on the steering wheel to do other useful work. Looking at a race car as a system, surely mechanical is better than human.

I agree with all you say, however the only reason the current 'seamless' gearboxes work in F1 is because the huge levels of downforce mask any unbalancing the shifts would otherwise cause in the cars.