The correct/smoothest way to change gear
Discussion
Whilst driving last night I was thinking about smoothing out my gear changes. Â
This has been slightly difficult recently as despite having a new clutch fitted, the revs were holding for a bit and not falling quite like they should be due to map sensor/boost leaks which are now hopefully gone..
Anyways say your changing up a gear at around 40mph and that speed equates to 5k rpm in 2nd gear and 3k rpm in 3rd gear.
Normally without really thinking about it I would accelerate to 5000 rpm in 2nd, put the clutch in, the revs would then fall to say around 2800, then release the clutch, the revs would then increase to 3000 and i would continue accelerating.
Last night I tried changing up slightly quicker (5000 rpm in 2nd, put the clutch in, revs fall to exactly the right engine speed for the road speed in that gear (3000 in this case) and continue.
Obviously the second method is the most correct smoothest way of changing up right?
Would the first method increase clutch wear significantly when compared with the second?Â
This has been slightly difficult recently as despite having a new clutch fitted, the revs were holding for a bit and not falling quite like they should be due to map sensor/boost leaks which are now hopefully gone..
Anyways say your changing up a gear at around 40mph and that speed equates to 5k rpm in 2nd gear and 3k rpm in 3rd gear.
Normally without really thinking about it I would accelerate to 5000 rpm in 2nd, put the clutch in, the revs would then fall to say around 2800, then release the clutch, the revs would then increase to 3000 and i would continue accelerating.
Last night I tried changing up slightly quicker (5000 rpm in 2nd, put the clutch in, revs fall to exactly the right engine speed for the road speed in that gear (3000 in this case) and continue.
Obviously the second method is the most correct smoothest way of changing up right?
Would the first method increase clutch wear significantly when compared with the second?Â
Yes, technically, the larger the number of revs between the engine speed and gearbox speed, the more the clutch will wear.
In reality 200rpm is neither here nor there and should give a smooth gear change. I've been out with people who hold the clutch in long enough for the revs to drop to idle before changing gear, very unpleasant.
Many cars have software built into the ECU which will automatically hold the revs close to where they need to be, presumably to preserve the clutch. For example the new Focus 1.6, when changing down from say 2000 rpm in 5th to 4th, the ECU holds the revs at about 3k. It doesn't exactly match the revs, but it would help a bit if you can't change gear properly yourself
.
In reality 200rpm is neither here nor there and should give a smooth gear change. I've been out with people who hold the clutch in long enough for the revs to drop to idle before changing gear, very unpleasant.
Many cars have software built into the ECU which will automatically hold the revs close to where they need to be, presumably to preserve the clutch. For example the new Focus 1.6, when changing down from say 2000 rpm in 5th to 4th, the ECU holds the revs at about 3k. It doesn't exactly match the revs, but it would help a bit if you can't change gear properly yourself
. Edited by BigTom85 on Wednesday 22 February 17:06
Edited by BigTom85 on Wednesday 22 February 17:07
It may be the way you wrote your OP, but fergudsake, you can't just match the engine speed with wheel speed... you need to match all the derivatives with each other too... in other words you need the engine speed accellerating or decellarting just like your wheels are.
You can easily do this with sensitve throttle with most cars. If you literally wanna match engine & gearbox speed all you actually have to do on a synchro box, which is any normal maual box, is lean on it for pressure until it slots in, then it will slot in and it'll be jerky as fook.
FFS moderate the throttle as well!
You can easily do this with sensitve throttle with most cars. If you literally wanna match engine & gearbox speed all you actually have to do on a synchro box, which is any normal maual box, is lean on it for pressure until it slots in, then it will slot in and it'll be jerky as fook.
FFS moderate the throttle as well!
Keep practising. Practice makes perfect, and leads to more satisfaction. Your explanation is spot on. Somewhatfoolish, as for accelerating or decelerating, that's pretty hard to do, since the car does exactly the opposite of what you want - i.e. if you are accelerating but back off to change gear, the car stops accelerating until you re-engage the clutch and start applying throttle again. If you are decelerating and dip the clutch, the car speeds up momentarily.
What you are aiming for is for you to be in control of the process, so aim to maintain the revs yourself, rather than just trying to get the gear change done in exactly the right length of time as they drop. So - back off throttle but not completely, dip clutch, adjust revs if required with right foot, select new gear, re-engage clutch. Your aim should be for the rev-counter needle to remain completely still as the clutch comes up.
What you are aiming for is for you to be in control of the process, so aim to maintain the revs yourself, rather than just trying to get the gear change done in exactly the right length of time as they drop. So - back off throttle but not completely, dip clutch, adjust revs if required with right foot, select new gear, re-engage clutch. Your aim should be for the rev-counter needle to remain completely still as the clutch comes up.
Edited by Mr Grayson on Friday 16th March 13:56
Two quick thoughts:-
i) when accelerating or decelerating find the neutral throttle for the speed before you do the gear change so that you unload the transmission before separating bits of it. Even if accelerating hard, lift the throttle to neutral just before the upshift.
ii) remember there are two breaks in the transmission -- clutch wear (engine to layshaft) is just one point. You also want to match layshaft speed to wheel speed before selecting gear to reduce the synchro wear if you can.
i) when accelerating or decelerating find the neutral throttle for the speed before you do the gear change so that you unload the transmission before separating bits of it. Even if accelerating hard, lift the throttle to neutral just before the upshift.
ii) remember there are two breaks in the transmission -- clutch wear (engine to layshaft) is just one point. You also want to match layshaft speed to wheel speed before selecting gear to reduce the synchro wear if you can.
I seldom drive manual vehicles but , when I do , I tend to double declutch at first : this slows down the gear change into two distinct parts and allows time to match revs ; after a while and once you get good at it you can dispense with the clutch altogether ( other than moving off from rest ) and execute the smoothest gear changes without using the clutch at all , it all comes down to timing and throttle modulation .
Whilst there is a certain satisfaction from a perfectly executed gearchange , I would still take an automatic any day of the week .
Whilst there is a certain satisfaction from a perfectly executed gearchange , I would still take an automatic any day of the week .
I have , of course , tried it in many different vehicles - the 'rubbery' gearchanges in modern vehicles does nothing for me .
Regardless of what my left foot is doing , I still time my gearchanges in a ' one , pause , two ' type movement , allowing time to match revs , the actual time obviously varies from one vehicle to another , but is still a long time to kick your left foot out on a single declutch .
Unless I have been driving some classic machinery which imparts tactile pleasure in the operation of its controls , I am always glad to get back to my automatics after driving something with more pedals than I have feet .
Regardless of what my left foot is doing , I still time my gearchanges in a ' one , pause , two ' type movement , allowing time to match revs , the actual time obviously varies from one vehicle to another , but is still a long time to kick your left foot out on a single declutch .
Unless I have been driving some classic machinery which imparts tactile pleasure in the operation of its controls , I am always glad to get back to my automatics after driving something with more pedals than I have feet .
Pontoneer said:
Regardless of what my left foot is doing , I still time my gearchanges in a ' one , pause , two ' type movement , allowing time to match revs , the actual time obviously varies from one vehicle to another , but is still a long time to kick your left foot out on a single declutch
Make the pause a little shorter?You may find that modern vehicles will last for many years with even the most ham-fisted shifts, so your method, although not incorrect, is not really required for even a smooth, rev-matched shift.
MC Bodge said:
Make the pause a little shorter?
You may find that modern vehicles will last for many years with even the most ham-fisted shifts, so your method, although not incorrect, is not really required for even a smooth, rev-matched shift.
Well no, if you don't leave enough time for the revs to fall, it's going to be a bad shift. As he said, the pause is different for every car, but the pedal does stay on the floor briefly for every shift IMV.You may find that modern vehicles will last for many years with even the most ham-fisted shifts, so your method, although not incorrect, is not really required for even a smooth, rev-matched shift.
davepoth said:
MC Bodge said:
Make the pause a little shorter?
You may find that modern vehicles will last for many years with even the most ham-fisted shifts, so your method, although not incorrect, is not really required for even a smooth, rev-matched shift.
Well no, if you don't leave enough time for the revs to fall, it's going to be a bad shift. As he said, the pause is different for every car, but the pedal does stay on the floor briefly for every shift IMV.You may find that modern vehicles will last for many years with even the most ham-fisted shifts, so your method, although not incorrect, is not really required for even a smooth, rev-matched shift.
pontoneer said:
I seldom drive manual vehicles but , when I do , I tend to double declutch at first : this slows down the gear change into two distinct parts and allows time to match revs ; after a while and once you get good at it you can dispense with the clutch altogether ( other than moving off from rest ) and execute the smoothest gear changes without using the clutch at all , it all comes down to timing and throttle modulation .
....but is still a long time to kick your left foot out on a single declutch
....but is still a long time to kick your left foot out on a single declutch
I've not found this to be a problem myself
....and yes, I do know how to double-de-clutch and do clutchless shifts, but don't do so on a regular basis as I see no need.
Edited by MC Bodge on Monday 19th March 22:48
I concentrated on how I shift this evening. Letting the revs fall on my somewhat less than light/revvy turbodiesel during one of my typically smooth, unhurried up-shifts didn't require much of a delay before re-engaging the clutch. I certainly didn't feel that the clutch pedal was down for long.
There's a danger of making something that is actually very simple into something complicated.
There's a danger of making something that is actually very simple into something complicated.
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