Changing gears properly.

[L.G.S]

Novice here, but I didn't know where to put it.

When changing gears, can you give a little gas to get the car moving WHILE lifting up the clutch like you do with the first gear, or does the clutch have to be fully up before applying any gas?

[deeps]

Yes you can do what ever you want as long as it's done safely . Have a play with it and see what happens for youself.

It's called rev matching and is a smooth way of changing down gears.

If you give it plenty of revs when changing up gears from say 1st to 2nd you'll get a bit of wheel spin, and for even better acceleration hardly lift the throttle at all between very quick gear changes.

I'll get told off now for saying that

[GravelBen]

L.G.S said:

Novice here, but I didn't know where to put it.

When changing gears, can you give a little gas to get the car moving WHILE lifting up the clutch like you do with the first gear, or does the clutch have to be fully up before applying any gas?

If you can hold the revs at the point where they stay the same as you let the clutch out (ie the clutch isn't dragging the revs up or down) then you've got it just right

As said above, play around and see what happens, try and keep everything feeling nice and smooth.

[waremark]

L.G.S said:

Novice here, but I didn't know where to put it.

When changing gears, can you give a little gas to get the car moving WHILE lifting up the clutch like you do with the first gear, or does the clutch have to be fully up before applying any gas?

Very much so, you should be doing something like that. You can either take your foot right off the accelerator as you press the clutch, then go back on the accelerator in time to get the revs up to the right level for the next gear; or you can keep your foot slightly on the accelerator the whole time so that the revs never die away. The one thing you should not do is let the revs drop to idle, and then let the clutch out in the new gear so that the revs get dragged up by the clutch.

How long have you been driving. Do consider an advanced driving course.

[GreenV8S]

L.G.S said:

Novice here, but I didn't know where to put it.

When changing gears, can you give a little gas to get the car moving WHILE lifting up the clutch like you do with the first gear, or does the clutch have to be fully up before applying any gas?

Yes, but in the sense of using the throttle to hold the revs at the right speed for the new gear while you engage the clutch so the engine revs don't change as the clutch engages. What is not so good is to hold the revs too high and then pull them down with the clutch.

[mph999]

L.G.S said:

Novice here, but I didn't know where to put it.

... give a little gas to get the car moving WHILE lifting up the clutch

Ideally, no.

You said "like you do with first gear" so I presume you talking about gear changing once moving ?

If you are going up the box, then the revs drop between each gear, for a given speed. Whilst the clutch is down you would maintain enough pressure on the gas so the revs don't drop to idle, and then bring the clutch up, before applying more gas, if you wish to accelerate.

If you apply the gas, as the clutch is still coming up, you slip the clutch, only a little, but add that up over many 1000's of gear changes and it's a lot of wear, in fact, it is this wear that eventually destroys the clutch.

OK, it's a tiny bit slower to make progress, as you have to "wait" before getting on the gas, not enough of a time loss to worry about, what, a second for gear change maybe.

Of course, when moving off, from rest, you have to slip the clusch a little.

Going down the box is similar, apart from you blip the gas to raise the revs to the correct point for the next gear, holding them there until the clutch is fully up.

Of course, with synro g/boxes, there is no cruntch, so it is difficult to know if you get absolutly spot on, but if you aim for the width of the needle, then there is neglegable wear on the clutch.

A clutch should be able to last the lifetime of a car, or, at least 100K.

Martin

[Dr Jekyll]

mph999 said:

L.G.S said:

Novice here, but I didn't know where to put it.

... give a little gas to get the car moving WHILE lifting up the clutch

Ideally, no.

You said "like you do with first gear" so I presume you talking about gear changing once moving ?

If you are going up the box, then the revs drop between each gear, for a given speed. Whilst the clutch is down you would maintain enough pressure on the gas so the revs don't drop to idle, and then bring the clutch up, before applying more gas, if you wish to accelerate.

If you apply the gas, as the clutch is still coming up, you slip the clutch, only a little, but add that up over many 1000's of gear changes and it's a lot of wear, in fact, it is this wear that eventually destroys the clutch.

OK, it's a tiny bit slower to make progress, as you have to "wait" before getting on the gas, not enough of a time loss to worry about, what, a second for gear change maybe.

Of course, when moving off, from rest, you have to slip the clusch a little.

Going down the box is similar, apart from you blip the gas to raise the revs to the correct point for the next gear, holding them there until the clutch is fully up.

Of course, with synro g/boxes, there is no cruntch, so it is difficult to know if you get absolutly spot on, but if you aim for the width of the needle, then there is neglegable wear on the clutch.

A clutch should be able to last the lifetime of a car, or, at least 100K.

Martin

I always take the view that if you and your passengers can't feel any jerk, so they can't tell when the clutch comes up without looking, that's close enough.

[norasport]

You should find that, when changing gear, say from 3rd to 4th there is a natural speed of decay of the revs, as you lift off the throttle, which allows the revs to match exactly with the new gear at the current road speed.
Watch the rev counter if you have one, to see if the needle flicks up or down when you come off the clutch, and then try to change the timing of the change to avoid this happening.

Clutchless changes become possible, but I am not suggesting you try this!, if the revs and road speed are matched.

[G51CAV]

For smoother changes bring your car to the appropriate speed for the conditions then try sustaining some revs when changing down, when changing up ease off the accelerator.

When I done my advanced police driving they way it was put to me was foot up to change up and foot down to change down. That's not foot to the floor mind, just keeping it on a little and make sure you have ample time to slow or stop as necessary.

It just comes down to practice and knowing the vehicle you're driving.

[jaf01uk]

What your aiming to do is match the revs to what they are going to be in the next gear as you change, the way to do it is make yourself familiar with the characteristics of your car, ie. do say 15mph in 1st and note the revs (eg.4500rpm) then do the same speed in 2nd and see what the revs are (poss. 3500rpm?), this is what your trying to allow the revs to drop to when changing gear - dont come completely off the gas while changing - keep the revs on "fast idle" but most of all come off the clutch slowly to allow any mismatch to be taken up smoothly by the engine.
Going down the box is the same but you stay on the gas ie. check the revs in 4th - 3500rpm? then same speed in 3rd - 4500rpm? so you have 2 options 1, blip the revs as you change gear aiming to have 4500revs on when you come slowly off the clutch or 2, ease off the revs so the car is holding speed in 4th then keep your right foot exactly where it is and as you push the clutch in releasing the engine from having to pull the weight of the car the revs will pick up to near enough the exact revs you need in the lower gear (3rd) sustained rev gearchange - white mans magic!
Gary

[_rubinho_]

My driving instructor (not advanced) taught me to keep my foot on the gas momentarily after pressing the clutch for an upchange and then release. This would cause the revs to increase quickly as the engine is unloaded. The aim was to allow them to drop naturally not to idle but the revs at which you'll be in the next gear as you come up off the clutch after the change. Once through the biting point, gas would be applied normally (the gearchange is effectively over at this time). I've been practising this ever since. It results in smooth but slightly noisier (due to the quick rise in revs as the clutch dips) changes.

[Martin A]

Hi All

_rubinho_ said:

My driving instructor (not advanced) taught me to keep my foot on the gas momentarily after pressing the clutch for an upchange and then release. This would cause the revs to increase quickly as the engine is unloaded. The aim was to allow them to drop naturally not to idle but the revs at which you'll be in the next gear as you come up off the clutch after the change. Once through the biting point, gas would be applied normally (the gearchange is effectively over at this time). I've been practising this ever since. It results in smooth but slightly noisier (due to the quick rise in revs as the clutch dips) changes.

Few instructors are knowledgeable enough about the subjects of vehicle dynamics, person to vehicle interaction, cognotive psychology, and car control to explain them in sufficient detail to those Learners who may be interested in becoming expert drivers. What your (rubinho) instructor should have got you to do is to keep your foot on the gas pedal but raise it slightly, allowing the revs to drop to the correct revs for the next gearchange. This will result in an even smoother and quieter change.

Strange as it might seem the revs will not always rise if you keep your foot in the same position once the clutch is depressed, they may fall depending on circumstances. By keeping your gearchanges unhurried you will be able to notice this and compensate by increasing the gas to raise the revs to the correct level if necessary.

Hope this helps.

Best regards,

Martin A

[p1esk]

Martin A said:

Few instructors are knowledgeable enough about the subjects of vehicle dynamics, person to vehicle interaction, cognotive psychology, and car control to explain them in sufficient detail to those Learners who may be interested in becoming expert drivers.

My driving instructors(1) were sufficiently knowledgeable to appreciate that their pupil had such an extraordinary degree of natural talent that they didn't need to explain all this stuff in great detail, 'coz everything clicked into place quite easily.

I soon came to the conclusion that they were actually genuine driving enthusiasts - it wasn't just a job to them - and I remain grateful for the tuition I received from Alan Brown and Alan Berriman in Scarborough approx.51.5 years ago.

Aside from my seemingly interminable clowning, that is a genuine sentiment.

(1) They had to share the load between them, neither one could cope on his own.

Best wishes all,
Dave.

[jaf01uk]

Martin A said:

Hi All

_rubinho_ said:

My driving instructor (not advanced) taught me to keep my foot on the gas momentarily after pressing the clutch for an upchange and then release. This would cause the revs to increase quickly as the engine is unloaded. The aim was to allow them to drop naturally not to idle but the revs at which you'll be in the next gear as you come up off the clutch after the change. Once through the biting point, gas would be applied normally (the gearchange is effectively over at this time). I've been practising this ever since. It results in smooth but slightly noisier (due to the quick rise in revs as the clutch dips) changes.

Few instructors are knowledgeable enough about the subjects of vehicle dynamics, person to vehicle interaction, cognotive psychology, and car control to explain them in sufficient detail to those Learners who may be interested in becoming expert drivers. What your (rubinho) instructor should have got you to do is to keep your foot on the gas pedal but raise it slightly, allowing the revs to drop to the correct revs for the next gearchange. This will result in an even smoother and quieter change.

Strange as it might seem the revs will not always rise if you keep your foot in the same position once the clutch is depressed, they may fall depending on circumstances. By keeping your gearchanges unhurried you will be able to notice this and compensate by increasing the gas to raise the revs to the correct level if necessary.

Hope this helps.

Best regards,

Martin A

I would be interested to know in what circumstances the revs would drop if you were maintaining road speed when the clutch is depressed?
Gary

[GreenV8S]

jaf01uk said:

I would be interested to know in what circumstances the revs would drop if you were maintaining road speed when the clutch is depressed?
Gary

If you have engine braking applied then the revs would drop when you declutch. This could occur at constant road speed if you are in a descent.

[jaf01uk]

GreenV8S said:

jaf01uk said:

I would be interested to know in what circumstances the revs would drop if you were maintaining road speed when the clutch is depressed?
Gary

If you have engine braking applied then the revs would drop when you declutch. This could occur at constant road speed if you are in a descent.

I'm sorry to be blunt but did you read the maintaining speed part? how can you have engine braking whilst maintaining speed? What you describe above is decelerating. At no time in the original post or the one above was downhill ever mentioned, it was in reference to changing gear on the flat,
Gary

[deeps]

jaf01uk said:

GreenV8S said:

jaf01uk said:

I would be interested to know in what circumstances the revs would drop if you were maintaining road speed when the clutch is depressed?
Gary

If you have engine braking applied then the revs would drop when you declutch. This could occur at constant road speed if you are in a descent.

I'm sorry to be blunt but did you read the maintaining speed part? how can you have engine braking whilst maintaining speed? What you describe above is decelerating. At no time in the original post or the one above was downhill ever mentioned, it was in reference to changing gear on the flat,
Gary

I know what you're saying jaf, but slight throttle will maintain speed whilst engine braking, i.e. steep down hill - 2nd gear no throttle - engine braking would slow the vehicle, whereas a little throttle would maintain speed, as would 3rd gear no throttle.

So a typical change up - 2nd to 3rd steep down hill - could be heel on brake to prevent speeding up when dipping clutch, dip clutch, engine revs would now drop but instead of lifting off throttle to match 3rd gear we add more throttle with toe, heel still on brake, then raise clutch whilst realeasing brake and throttle and all should match smoothly.

Edited by deeps on Sunday 1st February 18:07

[GreenV8S]

jaf01uk said:

GreenV8S said:

jaf01uk said:

I would be interested to know in what circumstances the revs would drop if you were maintaining road speed when the clutch is depressed?
Gary

If you have engine braking applied then the revs would drop when you declutch. This could occur at constant road speed if you are in a descent.

I'm sorry to be blunt but did you read the maintaining speed part? how can you have engine braking whilst maintaining speed? What you describe above is decelerating. At no time in the original post or the one above was downhill ever mentioned, it was in reference to changing gear on the flat,
Gary

Sorry to be blunt, but yes I did read your question before replying and perhaps you should do the same.

It is possible to apply engine braking while maintaining speed if the vehicle is in a descent. Your question made no reference to level ground.

[jaf01uk]

But the whole topic being discussed is sustained rev gearchanging (presumably on the flat as no specific mention was made as to while going downhill by the OP) that is why when someone mentioned that the revs could drop when the clutch was put in was making me curious, what I said originally was that if you are driving along maintaining (holding speed steady) and you push the clutch in the revs will rise as the engine no longer has to pull the weight of the car and I stick by that, I have never in my experience managed or witnessed a drop in revs in that situation unless the gas has been lifted by the driver during the gearchange,
Gary

[GreenV8S]

jaf01uk said:

presumably on the flat as no specific mention was made as to while going downhill

I mentioned going down hill as it is a scenario that produces the effect you enquired about.