Discussion
Like no doubt a lot of you are, I tend to be always "thinking" about my driving, even when driving normally trudging to work and back. One thing that's always been in my mind is downshifting, when driving "normally". I.e. slow speeds, turning into a side road / onto a mini roundabout.
How do you do it? Drop the car into a lower gear and gently lift the clutch? Try and plip the throttle to rev-match? I find the latter more difficult at low speeds/revs, and always seems to induce a little bit of a jerk - and it still bugs me even if it's barely noticeable. The former always gives me bad thoughts about premature clutch wear. Is it unreasonable to expect to be able to smoothly downshift every time?
How do you do it? Drop the car into a lower gear and gently lift the clutch? Try and plip the throttle to rev-match? I find the latter more difficult at low speeds/revs, and always seems to induce a little bit of a jerk - and it still bugs me even if it's barely noticeable. The former always gives me bad thoughts about premature clutch wear. Is it unreasonable to expect to be able to smoothly downshift every time?
Howard- said:
Is it unreasonable to expect to be able to smoothly downshift every time?
No. You should be able to achieve a smooth downshift virtually every time. Depending on the gear and speed the critical control inputs to achieve this will vary but lifting the clutch smoothly and steadily and rev-matching is the key.Practice will make perfect.
which car is most problematic, the MX5 or the ST220? I found in my civic blipping the throttle and matching the gear speed is pretty easy, but i think thats because its a "revvy" engine. It depends on how aggressive with the revs you want to be.
For instance i could down shift 3rd-2nd anywhere from 40mph and below but that brings the revs up to about 6k which is a bit chav when pulling into the drive.....
Thinking about it i normally, clutch, shift gear , slight pause, blip throttle and release clutch smoothly... the slight pause gives you a little more room for matching the rpms.......
For instance i could down shift 3rd-2nd anywhere from 40mph and below but that brings the revs up to about 6k which is a bit chav when pulling into the drive.....
Thinking about it i normally, clutch, shift gear , slight pause, blip throttle and release clutch smoothly... the slight pause gives you a little more room for matching the rpms.......
A colleague was giving me a lift the other day and she downshifted without making any attempt to rev match. She didn't get in wrong, she just didn't do it, I practically got whiplash on every gearchange. Is this a common approach? I can't remember riding with anyone else quite like that.
Dr Jekyll said:
A colleague was giving me a lift the other day and she downshifted without making any attempt to rev match. She didn't get in wrong, she just didn't do it, I practically got whiplash on every gearchange. Is this a common approach? I can't remember riding with anyone else quite like that.
Seems to be in my experience!GingerWizard, at higher speeds (engine and road) rev-matching is easy in either car, I don't have a problem with doing a nice smooth downshift from 5th to 3rd at 50mph for example, or 3rd to 2nd at 30.. You get the idea. It's at lower speeds I'm wondering what the best technique is. Turning into a road for example, slowing from 30mph in 4th/3rd, dropping into 2nd as you're doing about 10mph preparing to turn. I can do it pretty smoothly, but I'd like to improve. Maybe I'm just weird
Edited by Howard- on Friday 6th August 17:58
I am curious if you might be 'rushing' the change? I have noticed that it is easy to get a change wrong when you are just coming off the brakes and just getting ready to start steering into, say, a junction. Sometimes doing it a touch earlier gives more separation and more time to get it right. I read somewhere that getting the gear change completed about an artic truck length before the junction is a decent rule of thumb - sure enough it works for me.
Normally I would actually do that, yes, but it seems a bit "wasteful" to shift into 2nd too fast and far from the junction.. Hmm. Perhaps I'm just getting too used to the lovely torqueyness of the Mondeo and not shifting down early enough.
I don't rush them, if anything I'll do it slower to minimise any jarring. You might be right about trying to do everything 'too quickly' though, now that I think about it.
It's really hard to describe/discuss techniques such as this, isn't it!!
So what process would we use for, say, this mini roundabout:
http://maps.google.co.uk/maps?f=q&source=s_q&a...
Performing the same manoeuvre that the E36 BMW has. I normally slow down, indicate, then shift to 2nd a few feet before making the turn. But at this point I struggle to decide between shifting into 2nd as the engine is barely above idle speed and letting the clutch slip/increase the engine speed, or gently rev matching as I shift down, potentially revving slightly too high and causing a slight jerkiness. Mechanical sympathy and smooth driving is my number 1 priority most of the time!
What a bizarre thread subject
I don't rush them, if anything I'll do it slower to minimise any jarring. You might be right about trying to do everything 'too quickly' though, now that I think about it.
It's really hard to describe/discuss techniques such as this, isn't it!!
So what process would we use for, say, this mini roundabout:
http://maps.google.co.uk/maps?f=q&source=s_q&a...
Performing the same manoeuvre that the E36 BMW has. I normally slow down, indicate, then shift to 2nd a few feet before making the turn. But at this point I struggle to decide between shifting into 2nd as the engine is barely above idle speed and letting the clutch slip/increase the engine speed, or gently rev matching as I shift down, potentially revving slightly too high and causing a slight jerkiness. Mechanical sympathy and smooth driving is my number 1 priority most of the time!
What a bizarre thread subject
Edited by Howard- on Friday 6th August 20:58
Edited by Howard- on Friday 6th August 21:00
Dr Jekyll said:
A colleague was giving me a lift the other day and she downshifted without making any attempt to rev match. She didn't get in wrong, she just didn't do it, I practically got whiplash on every gearchange. Is this a common approach? I can't remember riding with anyone else quite like that.
When my ex passed her driving test she took me for a drive. Whatever you do do not suggest to her that she should apply a bit of throttle to make the downshift smoother, it really isn't worth the grief you get for daring telling her now to drive.Later on in that drive I had to reach over the car to turn main beams off despite the ear ache as I didn't fancy a head on collision in a Citroen AX.
Never again!
just bring the clutch in slowly! don't worry about slipping the clutch, thats what the clutch is for - to smooth the difference between engine speed to road speed. any driver with a modicum of mechanical sympathy would never wear out a clutch anyway!
at the rpms of town driving, there isnt much engine braking which causes the lurch. id only ever blip when heel and toeing to keep the car in the power band, or when downshifting without slowing the car (ie preparing for an overtake).
i would say, approach junction, clutch in, keep light pressure on throttle to keep the revs constant, then reengage clutch when the car has slowed sufficiently to match the revs of the new gear.
at the rpms of town driving, there isnt much engine braking which causes the lurch. id only ever blip when heel and toeing to keep the car in the power band, or when downshifting without slowing the car (ie preparing for an overtake).
i would say, approach junction, clutch in, keep light pressure on throttle to keep the revs constant, then reengage clutch when the car has slowed sufficiently to match the revs of the new gear.
On the basis that you want to be at the speed that you are going to turn into the junction at and need to be in the right gear for that speed and have the car settled before you start to steer, the artic truck length rule of thumb allows enough time for that
As for that roundabout, on the basis that the SL is 30 and I am to do the same manouvere as the green BM...
Well, I have a pretty good view of the entrances to the rbt from far enough away that maybe I could judge that I could fit in without stopping easily enough. A signal at the point where it would be most beneficial to the guy in the van and/or any followers and, as it doesn't appear to be much of a turn, I'd might be able to hold 3rd all the way through the rbt whilst keeping the speed at a level that enabled me to stop in the distance I could see to be clear. From that picture (and its never easy to judge just from a picture) maybe taking 2nd is unnecessary - there is no rule that says rbt = 2nd.
Compared to the BM, my road position would be further to the right to afford more of a view into the road I am entering: I'd want to see as much of the nearside pavement as I could from as early as I could and I certainly wouldn't go any nearer to the grate that is level with the BM than I had to.
(In real life the above may be totally different from how I'd approach the rbt, the picture alone is not enough to properly make the call, but these are things I would consider).
As for that roundabout, on the basis that the SL is 30 and I am to do the same manouvere as the green BM...
Well, I have a pretty good view of the entrances to the rbt from far enough away that maybe I could judge that I could fit in without stopping easily enough. A signal at the point where it would be most beneficial to the guy in the van and/or any followers and, as it doesn't appear to be much of a turn, I'd might be able to hold 3rd all the way through the rbt whilst keeping the speed at a level that enabled me to stop in the distance I could see to be clear. From that picture (and its never easy to judge just from a picture) maybe taking 2nd is unnecessary - there is no rule that says rbt = 2nd.
Compared to the BM, my road position would be further to the right to afford more of a view into the road I am entering: I'd want to see as much of the nearside pavement as I could from as early as I could and I certainly wouldn't go any nearer to the grate that is level with the BM than I had to.
(In real life the above may be totally different from how I'd approach the rbt, the picture alone is not enough to properly make the call, but these are things I would consider).
Interesting theory and things to consider JP, thanks The roundabout is actually smaller and tighter than it looks in that picture that's for sure. The surface is pretty rough so going round in 3rd is a bit excessive IMHO.
http://maps.google.co.uk/maps?f=q&source=s_q&a... - See here for a totally different perspective
So you reckon change down a truck's length from the turn and then apply the brakes, or apply brakes at that point and then shift down?
OK different scenario that maybe more indictates my original query with regards to downshifting at a slow speed.. What about turning left into a side road? Where you obviously can't carry the same speed you would on a roundabout. What would your process be?
This all sounds so elementary, but really it's about perfecting one's technique
Maybe I need to read that copy of Roadcraft I have somewhere..
The roundabout is actually smaller and tighter than it looks in that picture that's for sure. The surface is pretty rough so going round in 3rd is a bit excessive IMHO.http://maps.google.co.uk/maps?f=q&source=s_q&a... - See here for a totally different perspective
So you reckon change down a truck's length from the turn and then apply the brakes, or apply brakes at that point and then shift down?
OK different scenario that maybe more indictates my original query with regards to downshifting at a slow speed.. What about turning left into a side road? Where you obviously can't carry the same speed you would on a roundabout. What would your process be?
This all sounds so elementary, but really it's about perfecting one's technique
Maybe I need to read that copy of Roadcraft I have somewhere..Edited by Howard- on Saturday 7th August 09:59
Edited by Howard- on Saturday 7th August 10:03
Lets say you are doing a left turn into a side road from the main road. 90 degree. In town. Slow.
You are probably in third and will need, say, first.
Brake gently then firmly then gently down to 5 mph in third. Foot off brakes. Declutch. Into first. Don't bother with rev matching - tickover will be fine - smoothly lift clutch. Count 1-2-3 whilst lifting the clutch to make sure you don't do it too quickly.
It should re-engage drive absolutely smoothly.
Apply throttle to maintain 5 mph whilst steering around the sharp corner. And away.
Less sharp? Need second? The speed will probably be 10mph or so and you might want the slightest trace of throttle as you slip the clutch out 1-2-3.
Less sharp again, higher speed: time to rev-match.
In any event ensuring you are in gear with the clutch fully out prior to needing to steer through the hazard will mean you have time to devote to making the shift smooth.
You are probably in third and will need, say, first.
Brake gently then firmly then gently down to 5 mph in third. Foot off brakes. Declutch. Into first. Don't bother with rev matching - tickover will be fine - smoothly lift clutch. Count 1-2-3 whilst lifting the clutch to make sure you don't do it too quickly.
It should re-engage drive absolutely smoothly.
Apply throttle to maintain 5 mph whilst steering around the sharp corner. And away.
Less sharp? Need second? The speed will probably be 10mph or so and you might want the slightest trace of throttle as you slip the clutch out 1-2-3.
Less sharp again, higher speed: time to rev-match.
In any event ensuring you are in gear with the clutch fully out prior to needing to steer through the hazard will mean you have time to devote to making the shift smooth.
Thanks.. I think where I've been going wrong is I've tried to "blip" the throttle, even when very gentle slow speed downshifts like this one, where I should be "rolling" the throttle up very gently whilst releasing the clutch.. All stuff to think about when I'm next on the road anyway Thanks
Thanks Howard- said:
Thanks.. I think where I've been going wrong is I've tried to "blip" the throttle, even when very gentle slow speed downshifts like this one, where I should be "rolling" the throttle up very gently whilst releasing the clutch.. All stuff to think about when I'm next on the road anyway Thanks
Once you've got it sorted you will find it becomes an ingrained *good* habit of smooth driving. There mere fact you are interested in achieving it guarantees success! Thanks It's amazing how many people have ingrained bad habits of rough, jerky driving, though.
I honestly believe that most drivers would be significantly better off in nearly all circumstances with an automatic.
(Yes I drive one day to day).Don said:
I honestly believe that most drivers would be significantly better off in nearly all circumstances with an automatic. (Yes I drive one day to day).
Probably (Yes I drive one day to day).It irks me greatly when I experience driving that isn't smooth. If I'm with someone who makes no effort to match revs when up/downchanging at speed, holding the clutch in with it in gear for ages at lights or whatever.. I just think "I'm glad that's not my drivetrain"
I like to think my driving is smooth and it's always "on my mind" when driving, as well as every other aspect such as observation and awareness. It's just this tiny little section of it that I think I can improve upon
Edited by Howard- on Saturday 7th August 10:31
Edited by Howard- on Saturday 7th August 10:32
Howard- said:
So you reckon change down a truck's length from the turn and then apply the brakes, or apply brakes at that point and then shift down?
OK different scenario that maybe more indictates my original query with regards to downshifting at a slow speed.. What about turning left into a side road? Where you obviously can't carry the same speed you would on a roundabout. What would your process be?
Brakes first, get the speed down to where you want it, off the brakes, then select the gear appropriate for that speed. Balanced engine speed and clutch engaged, then start the steeringOK different scenario that maybe more indictates my original query with regards to downshifting at a slow speed.. What about turning left into a side road? Where you obviously can't carry the same speed you would on a roundabout. What would your process be?
Most left turns into side roads are 2nd gear IME, sometimes 1st. As Don says, get the braking done first of all. Once you are at the speed for the turn, off the brakes, take the gear, clutch up with balanced engine speed then start the steering
Howard- said:
Like no doubt a lot of you are, I tend to be always "thinking" about my driving, even when driving normally trudging to work and back. One thing that's always been in my mind is downshifting, when driving "normally". I.e. slow speeds, turning into a side road / onto a mini roundabout.
How do you do it? Drop the car into a lower gear and gently lift the clutch? Try and plip the throttle to rev-match? I find the latter more difficult at low speeds/revs, and always seems to induce a little bit of a jerk - and it still bugs me even if it's barely noticeable. The former always gives me bad thoughts about premature clutch wear. Is it unreasonable to expect to be able to smoothly downshift every time?
Thing is you have to find the best way for the vehicle you are driving.How do you do it? Drop the car into a lower gear and gently lift the clutch? Try and plip the throttle to rev-match? I find the latter more difficult at low speeds/revs, and always seems to induce a little bit of a jerk - and it still bugs me even if it's barely noticeable. The former always gives me bad thoughts about premature clutch wear. Is it unreasonable to expect to be able to smoothly downshift every time?
What is your vehicle?
Petrol or diesel?, it's obviously manual but cable or DBW throttle?
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