Motoring Discussion > Making smooth progress Miscellaneous
Thread Author: WillDeBeest Replies: 41

 Making smooth progress - WillDeBeest
I've been mainly an automatic driver for most of the last three years, with my manual driving confined to occasional runs in the S60, which required a certain amount of finesse to drive around the foibles of its slightly obstructive gear linkage.

Now I've had a couple of weeks of regular manual driving. The TDS's gearchange is meaty rather than sweet - it's clearly designed to handle significant torque and makes little attempt to hide it - and the clutch pedal is weightier than average too. That's OK; it's a powerful car and a but of physical effort is a subliminal reminder that it's to be treated with respect.

But I'm puzzled by my gearchanges. Sometimes they can be baby-bottom smooth, while others, with no obvious major difference in timing or technique, feel clumsy to the point where I feel I ought to apologize to the car - and sometimes do. Perhaps I was compensating more than I realized for the S60's age - or perhaps I'm just out of practice.

Now there are experts who advise that a smooth gearchange is a slow gearchange, but if there is any difference between my 'good' and 'bad' changes, it's that the worst are when I set out to be slow, deliberate and as smooth as possible - I was bored in a jam on the M4 on Friday and it's not easy to make successive 1-2-trundle-brake-stop progressions anything but monotonous - and the best when I forget the mechanics and JFDI.

So how do you do it? Are you a snatcher, a wrestler, a glider or a scrupulous rev-matcher? And how long does it take you to adjust to a new regular drive?




*Two-Door Saloon
 Making smooth progress - No FM2R
For me its nothing to do with the change, its all to do with the clutch foot.

It gets out of practice for smooth and gentle, and loses the ability to quickly adapt.

I find it comes back since I rarely drive a manual, but I have an old-ish manual Nissan Pickup and it just seems to take a bit of time.

Mind you, not days, just an hour or so.

And I wouldn't say that changing quick or slow was the answer, a measured beat works for me.
 Making smooth progress - Cliff Pope
>> For me its nothing to do with the change, its all to do with the
>> clutch foot.
>>
>>

Absolutely. You can't mess up the actual process of shifting the lever from one cog to another with a syncromesh gearbox in good condition, because that's what the snchromesh is for.
You can only go wrong if it is an old crash gear and you don't successfully match the speeds, or the syncro is a bit tired and you move the lever too fast so it can't respond in time.

But even if the syncromesh takes care of the actual gear change, you still have to match engine speed to gearbox when you re-connect the clutch, otherwise there is a jerk or snatch.
That means taking your foot off the accelerator when changing up, because the revs need to be lower, or speeding up the engine when changing down because the revs need to be higher.

That can be tricky if you need to brake at the same time. If you just let the clutch in regardless then you get that sickening jerky deceleration as the car tries to speed the engine up via the clutch plate. i think it's one reason some people wear out clutches much faster than others - apart from excess revs when pulling away of course.

The secret is to perfect heel-and-toeing, or left-and-right soleing depending on your brake/accelerator positions. It's sneered at as old man stuff from the old days, but really you can't do a smooth downward gearchange at the same time as braking if you don't use it.
It's also a useful skill to have if your handbrake is poor and won't hold on a steep hill.
 Making smooth progress - bathtub tom
>> You can't mess up the actual process of shifting the lever from one cog to another

I'll dispute that. I sold one car to an elderly bloke who just couldn't select the gears. He was grabbing a fistful of gearlever and trying to force it where he thought the gear ought to be. I tried to show him that all the gearlever needed was a thumb and two fingers worth of gentle pressure, but he couldn't manage it.
 Making smooth progress - Alastairw
Could be the modern ECU. Ie: when you come off the throttle to make the change the car might hold onto more revs than you expect, thereby making the change jerky. I had a similar problem when I first had the Octavia, but 5 years practice has largely ironed it out.
 Making smooth progress - Armel Coussine
I'm a more or less automatic and unconscious rev-matcher. Not many of my gearchanges are especially noticeable. But you can't win them all. Everyone does something clumsy from time to time. But I don't punish the transmission unduly.
 Making smooth progress - Slidingpillar
As a rule, changes in gear on the three wheeler have to be smooth as if the dogs don't line up, it's not going to engage. No sycromesh does rather concentrate the mind. However, with only two gears to choose from, you don't have to change very often.
 Making smooth progress - J Bonington Jagworth
Does anyone else double-declutch? I was taught that way and also drove a Land-Rover (synchro on 3 and 4 only) for years - it seems to work and I like to think it's mechanically sympathetic, if not strictly necessary!
 Making smooth progress - Armel Coussine
My car's got synchro on all gears but it pays to double-declutch changing into first on the move. An old habit anyway because most cars had a crash bottom gear until a few years ago.
 Making smooth progress - Slidingpillar
The trike will make upwards changes with a single clutch dip if you time it right. Not difficult. Downwards, double decluching is needed. It's not going in if you don't.
 Making smooth progress - WillDeBeest
No. I tried it once out of curiosity after reading something and didn't bother again. But I do buy into the idea of a 3-neutral-2 shift, or whatever. Seems more sympathetic to the selector mechanism.

Alastair's point about the ECU is an interesting one. I have two small, low-speed roundabouts to negotiate on the estate roads near my house. Approaching one under gentle braking in second, I get what feels like a surge just before I'm ready to dip the clutch. I suspect this is the ECU injecting fuel a little earlier than I'm used to to keep the engine from stalling, possibly because second and third are a little higher (12 and 19 mph per 1000rpm, where the Volvo's were more like 10 and 17.)
 Making smooth progress - Old Navy
It is because (I assume) you are human. Your coordination will vary slightly as will the gear change parameters. Most of the time you will get it right, occasionally not quite right. Anyone who has a 100% perfect gear change record is delusional.
Last edited by: Old Navy on Mon 15 Jun 15 at 18:29
 Making smooth progress - ....
I'm still getting to grips with the S60.
My previous S60 similar to yours would idle at 700rpm and just pull in any gear without any throttle.
The newer car idles at 800rpm and adds throttle taking the revs up to 1000rpm on release of the clutch pedal.
The old S60 was impossible to stall, the newer car can be stalled like a petrol.
 Making smooth progress - Bromptonaut
>> The old S60 was impossible to stall, the newer car can be stalled like a
>> petrol.

We'd noticed that trend too.

It took brutality, like a foot slipping off the clutch, to stall the XUD engines in a BX or 205, same goes for the last generation IDI DW8B unit in my 2005 Berlingo. The first generation HDi in the Xantia could be stalled but only if you were a wee bit ham fisted. The HDi in the newer 'lingo - 1.6/115 - just needs chance or carelessness.

Suspect there's a deliberate use of electronics to make it feel like a petrol.
Last edited by: Bromptonaut on Mon 15 Jun 15 at 19:44
 Making smooth progress - Manatee

>> Suspect there's a deliberate use of electronics to make it feel like a petrol.
>>

You still wouldn't make it stall like a petrol if that was the sole objective.

More likely it is programmed to stall rather than allow kangarooing to damage the DMF / crank damper.
 Making smooth progress - ....
Why do current diesels 'need' to stall?
My old S60 had a DMF and cat in the exhaust. The new car has DPF and needs to blip the throttle when releasing the clutch pedal. Is this due to increased back pressure from the filter which would otherwise stall the engine?
 Making smooth progress - Manatee
>> The new car...needs to blip the throttle when releasing the clutch pedal.

Do you mean releasing the pedal and engaging the clutch to set off, or depressing the pedal and releasing the clutch to stop or select a gear?
 Making smooth progress - ....
Sitting with engine idling depress the clutch pedal, do not select a gear leave in neutral and release the pedal. The revs will rise to 1000rpm before dropping back to 800rpm idle.
The car has not moved.
Last edited by: gmac on Mon 15 Jun 15 at 20:29
 Making smooth progress - Manatee
Interesting. Electronically controlled diesels increase fuel flow to maintain set RPM, which is why they are so easy to drive on tickover. Maybe the resistance increases as you release the clutch and it overshoots; or perhaps it is an anti-stall measure. I would hope the back pressure at 800 rpm isn't material.
 Making smooth progress - Bromptonaut
But that just replicates mechanical IDI diesels which were easy to drive on tickover.

I well remember the revelation in May 93, caught in a jam on the M8 in my newly acquired BX 1.9RD estate, discovering it would creep like a petrol auto with feet off everything.
 Making smooth progress - WillDeBeest
The 1986 Escort 1.1 that I learned in (petrol, manual, of course) used to do that. Come to think of it, so has every car I've ever had. Except the LEC, which goes too fast in first (and it is first - I've checked) and needs too many dabs on the brakes for easy crawling in traffic.

The TDS, incidentally, has an amazingly short first gear and creeps, even downhill, at an indicated 4mph. I get passed on the pavement by old ladies on racing tortoises.
Last edited by: WillDeBeest on Mon 15 Jun 15 at 21:01
 Making smooth progress - Armel Coussine
Just came back from the other end. A couple of noticeable gearchanges though, nothing gross, just noticeable.

Perhaps because I was ripped on Montilla. Oo-er! Just as well it's only a mile or so with no traffic in it after 4.
 Making smooth progress - Cliff Pope
>> The 1986 Escort 1.1 that I learned in (petrol, manual, of course) used to do
>> that. Come to think of it, so has every car I've ever had.

Surely any car with electronic idle speed control does that? My Volvo 240 will just amble along doing 800 rpm with feet off everything. I can even change into second and it does the same but a bit faster.

At low revs it's simply replicating a governed speed control, which on old diesels used to be mechanical.
 Making smooth progress - Bromptonaut
>> Surely any car with electronic idle speed control does that?

Quite likely, but I was comparing one of the best IDI diesels with its predecessors; a BX16RS, two Minis and a Pug 104ZS. All of which had carburettors.
 Making smooth progress - Manatee
>> >> The 1986 Escort 1.1 that I learned in (petrol, manual, of course) used to
>> do
>> >> that. Come to think of it, so has every car I've ever had.
>>
>> Surely any car with electronic idle speed control does that?

I was being overly pedantic when I mentioned diesels because the fuel is regulated to control engine speed. Petrol engines such as the one in my MX5 get more fuel too of course, but that is indirect as the idle control manages airflow and the measured airflow enbales the ECU to work out how much petrol to inject.

A mechanical governor did a similar job in older diesel engines.

But I am not up to date, I know. Whilst older diesels needed no throttle plate, newer ones do because they need more vacuum in the inlet tract to help recirculate exhaust gas for emission control; but AFAIK it has no role in managing engine speed.
 Making smooth progress - Armel Coussine
>> I get passed on the pavement by old ladies on racing tortoises.

:o}

Heh heh... that reminds me of someone i used to know, terrible chap when you got to know him... dangerous driver too. Frightening anyway.
 Making smooth progress - No FM2R
>>The 1986 Escort 1.1 that I learned in

You're either younger than you look or you came from posh. 1986, for goodness sakes. I didn't even get a 1982 until 1990.
 Making smooth progress - WillDeBeest
It was a driving school car, and it was 1988 by the time I got in it. Then it was mysteriously unavailable on the day of my test and I had an almost-new 1.3 instead. Liked that a lot, so when I found myself in Basingstoke the next year with a little money in the bank, I bought one of my own: G727 ABL. Posh? Hardly! Served me well, though.
 Making smooth progress - Avant
I was taught to double-declutch when I learned to drive in the mid-1960s - my mum's Morris 1100 didn't have syncromesh on first so it was a necessity.

I don't think it's needed nowadays, but blipping the accelerator with clutch down can still make sense if there's going to be a major difference in revs between one gear and another - e.g. going up a steep hill, or going down into first to get up the slope into our drive at home.
 Making smooth progress - WillDeBeest
OK, let's talk rev matching. Suppose I'm in fifth and decelerating towards 35 when I find I have a hill to climb or an overtaking opportunity and I want third. Now I know that third in my car gives 19mph per 1000rpm, so do I do the mental arithmetic and set the revs to exactly 1,842 before re-engaging the clutch? Or do I just give it a poke with my right foot, listen for the blip, lift with the left and hope for the best?
 Making smooth progress - Cliff Pope
>>set the revs to exactly 1,842 before re-engaging the clutch?
>> Or do I just give it a poke with my right foot, listen for the
>> blip, lift with the left and hope for the best?
>>

Neither. As an experienced driver practised in your car's characteristics you just instinctively know how much revs you need. As AC says, it's automatic. You don't need to think about it.

It's like learning to drive. A learner will memorise the revs needed before engaging the clutch, an experienced driver just does it.
 Making smooth progress - Armel Coussine
>> OK, let's talk rev matching. Suppose I'm in fifth and decelerating towards 35

You just go down through the gears in sequence, gently unless there's some emergency. This simply isn't a problem. Not even a conscious process, good as an auto really.
 Making smooth progress - WillDeBeest
You just go down through the gears in sequence...

Another thread, perhaps, but why, when the car is happy decelerating gradually in fifth? Modern driving practice is to wait until we need to accelerate and then block-shift to the right gear for that. Which does call for a bit of rev matching, since fifth at 35 might be only 1,200rpm or so.
 Making smooth progress - Armel Coussine
>> why, when the car is happy decelerating gradually in fifth? Modern driving practice is to wait until we need to accelerate and then block-shift to the right gear for that.

I'm sure you're right WDB. We all do that, and other stuff too. I'm leisurely by choice these days.

I haven't driven flat out through the gears in a c***'s age. Long may it remain so.
 Making smooth progress - No FM2R
>>OK, let's talk rev matching

For 6 weeks a million years ago I commuted between Bracknell & Wokingham in an Audi 100 with no clutch release.

I learned a lot about "rev matching". In the various manual cars I've had over the years, I've always managed to get up and down the gearbox without graunching without using the clutch.

A pointless activity though.
 Making smooth progress - Cliff Pope

>>
>> I don't think it's needed nowadays, but blipping the accelerator with clutch down can still
>> make sense if there's going to be a major difference in revs between one gear
>> and another -

But there is a difference between a blip in order to facilitate silent engagement of crash gears, and the constant higher speed needed as you engage the clutch in order to continue at the same speed but in a lower gear.

With a proper crash gearbox you need both - initial blip to get it into gear, then further constant higher revs to maintain speed. On an old car with a loud exhaust you get that lovely double boom in quick succession as a skilled driver storms a hill.
 Making smooth progress - sooty123
It can be mildly interesting to have a quick look through threads like this to see how much harder driving was back in the day. Lots more to think about, can't say I've ever thought about doing double declutching and all the rest of that stuff. I mean of course I've heard about it. But (I think) there's only one person I've seen do all that sort of thing.
Mind you I've only ever driven fuel injected cars with sychro g/boxes etc, so it's not really something I'd ever be interested in faffing about with. But each to their own.
 Making smooth progress - Armel Coussine
An age thing sooty. No longer necessary.

 Making smooth progress - Manatee
I regularly drove an ex-army Bedford RL lorry for a while as a youth, and double declutching was habitual. I had a couple of cars later with ineffective syncro that also benefitted from it. I soon learned to heel and toe (not literally) so as to combine it with braking when changing down.

I have now more or less settled for just bringing the revs up while passing through neutral (not a blip as Avant mentions) on a downchange but I still revert when driving enthusiastically, usually in the MX5. Mostly I don't think about it, I just do it.
 Making smooth progress - Runfer D'Hills
My father was already in his 50s when I was born. He learned to drive in the early 1920s in his father's car.

An excellent driver but one who of course never had to pass a test he went on to be a lifelong lover of cars and motorbikes, owning and driving many quite interesting vehicles over the years. He drove fast but smoothly with great accuracy and never had an accident. ( nor, coincidentally, have I, so far anyway, ever had one )

He taught me to drive, and one thing still resonates with me to this day which he repeatedly drummed into me. Whether he had heard this somewhere or whether it was just something he thought of I really don't know, but nonetheless it seemed/seems to work. He taught me to always imagine that there was a rather delicious glass of wine balanced on the bonnet which if it was still there at the end of the journey could be drunk as a reward for making smooth progress. And then having pictured the imaginary glass of wine to now drive as fast as I liked...

Particularly effective as a mental discipline in winter conditions too incidentally.

Try it, it does work.
 Making smooth progress - Cliff Pope

>> Try it, it does work.
>>
>>

Try it with a real glass of water - that'll teach you!


Another tip to remember occasionally is to imagine that the brakes don't work.

I have years ago actually driven a car like that. I was picking up a nearly defunct Saab 96 for spares, literally dragged out of a hedge. When I found the engine would actually run, sort of, it seemed easier to drive it home rather than tow it on a rope.
No tax, no MOT, no insurance, no brakes, collapsed rear suspension, no indicators, and not a lot of exhaust pipe. I don't do things like that now. :)
 Making smooth progress - Crankcase
This being the 21st century, if you want to try the "glass of water" trick that Runfer describes - well, there is of course an app for that. Although the reviews aren't that complimentary...


itunes.apple.com/gb/app/a-glass-of-water/id376721035?mt=8
Last edited by: Crankcase on Tue 16 Jun 15 at 09:12
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