Rev Matching & the mistakes made

Rev Matching & the mistakes made

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Young1

Original Poster:

10 posts

75 months

Wednesday 21st March 2018
quotequote all
Hi all,

I've decided to go for ROSPA for learning advanced driving, in the meantime I've decided to try and learn rev matching.

Upshifting is smooth, finding it quite easy, it's the downshift I'm having problems with.

Here's the mind and actions of Young1 behind his Punto. Sees a corner ahead, currently in 5th gear, maintains throttle foot where it is whilst changing into 3rd, speed is 40 at the change. Works well ish. Tries it again from 5th to 3rd, revs soar up and heavy engine breaking as I get back to normal revs.

The whole down changing feels really unnatural for me this method. I tried blipping but I kind of wimp out and half blip or do it rapidly as if I'm worried raising the revs would affect the car.

My questions are:
What speed should I be rev matching at? (The usual changing point for the gear so 3rd at 30mph)

What method should I use for the raising of revs? Blip or sustained throttle? I tried it a new way on my last drive a few minutes ago where I change down from 5th to 3rd at 30mph, engage the third gear, then put a little bit of gas as I lift the clutch slowly, minimising my potential for mistake, it works well.

Is this taught in ROSPA? I assume so but nevertheless.

Basically any tips to avoid me killing my car prematurely, because that's what it feels like I'm doing. Read zen and the art of changing gear.




akirk

5,385 posts

114 months

Wednesday 21st March 2018
quotequote all
I had a coaching session which included just this - about a week ago... the M5 I have has a light flywheel making it harder as revs fall off dramatically...
some thoughts:

- start by practising in higher gears (5-4) then move down (4-3 / 3-2) the higher drops are easier
- don't start by dropping two gears - apart from anything else, you are either starting in too high a gear / finishing in too low a gear / braking too hard and losing too much speed, meaning that you approached too fast.
- practise on a straight where you can go e.g. 5-4-5-4-5-4-5-4 - you should be able to do it eventually with no noticeable difference - and def. no drive train shunt - a passenger shouldn't even notice
- blip the throttle hard and then blip again to catch the revs at the right point - if you have more time - squeeze instead of blipping to take up to the correct rev range in one slower go

- approaching a corner you are braking - separate out braking and gear change (as per the Roadcraft IPSGA approach where Speed comes before Gear), this will minimise the rev difference

sounds as though over all you are going too fast in / changing speed too dramatically / not providing enough blip / bringing the actions too close together... join RoSPA and find someone to drive with you

Bigends

5,413 posts

128 months

Wednesday 21st March 2018
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Learn to double declutch - gives a lovely smooth downward change

waremark

3,242 posts

213 months

Thursday 22nd March 2018
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Bigends said:
Learn to double declutch - gives a lovely smooth downward change
Completely unnecessary in modern cars.

OP, it sounds as though you are changing down before finishing slowing. Slow to the speed for the hazard in good time - which probably means earlier than feels natural- leaving time for a relaxed gear change. Then take a gear which does not need high revs, say 3rd from 20 to 30, 2nd from 5 to 19, and apply just enough gas to hear the engine note rise from idle before releasing the clutch smoothly.

paua

5,687 posts

143 months

Thursday 22nd March 2018
quotequote all
waremark said:
Bigends said:
Learn to double declutch - gives a lovely smooth downward change
Completely unnecessary in modern cars.

OP, it sounds as though you are changing down before finishing slowing. Slow to the speed for the hazard in good time - which probably means earlier than feels natural- leaving time for a relaxed gear change. Then take a gear which does not need high revs, say 3rd from 20 to 30, 2nd from 5 to 19, and apply just enough gas to hear the engine note rise from idle before releasing the clutch smoothly.
Unnecessary or not, learn to do it anyway. It will make you a better driver - smoother & more mechanically sympathetic.

Baz4333

5 posts

82 months

Thursday 22nd March 2018
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It’s certainly to do with your speed, that way you shouldn’t have to rev the car too much to be able to smoothly match the engine speed.

It all depends on the situation and the hazard and don’t forget that as long as you are breaking with the clutch down, then you’re not coasting. Get the breaking phase completed before selecting the gear, as was drummed in to me on my driving courses, breaks are for slowing and gears are for going.

Len Woodman

168 posts

113 months

Thursday 22nd March 2018
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paua said:
Unnecessary or not, learn to do it anyway. It will make you a better driver - smoother & more mechanically sympathetic.
Agreed. I first learned to DDC on HPC in 1974 in an MGB as I was having trouble with clean changes. Soon after that I started driving heavy vehicles in the army - the Bedford RLs had syncho except on first. Few of the drivers could change into first unless they stopped. Then the AEC Militants and Antars were all crash boxes. After a couple of weeks driving them in Germany I used to be able to do the smoothest changes when back in my own MGB (as long as I took off my DMS boots!).

A few years ago I started 'single-clutching' in the Corolla I had - to preserve the clutch. I thought my gear changes were still okay. Then I spent a couple of days back in a manual truck; Hino with a 13 speed Eaton Road Ranger. Back to DDC and clutchless changes. After 20 years it all came back to me. After driving the pure crash gearbox trucks when I got in my car I impressed myself with my much smoother and accurate my gear changes. So I went back to my training at BSM HPC - DDC and no need to depress the clutch to the floor except stopping and moving away in first. With a Road Ranger 'box fully depressing the clutch after moving away destroys the clutch-brake. And I could sit further back with more comfort and better vision.

My current 2007 Astra 2.2 SRi has done 170,000 kms with no noticeable changes to the clutch.


akirk

5,385 posts

114 months

Thursday 22nd March 2018
quotequote all
DDC is not a bad skill to have and there are still cars on the road where it helps - it can also lead to a more leisurely and smoother transition...

however, as per my comments and Waremark's - in this scenario, as a first step it is not the correct answer
slow down earlier / less rapidly and the gear change will be easier

this is a classic example of the internal psychological pressure to maximise the road - meaning that the driver feels they need to brake as late as possible into a corner or they are losing progress - actually, braking earlier and separating the stages of the corner will give a smoother ride, and a better platform to allow acceleration out of the corner rather than fighting with brakes and gear changes in the corner - it is initially counter-intuitive, but when practised, becomes a much more fluid progress

so, simplest change is slow down!

Bigends

5,413 posts

128 months

Thursday 22nd March 2018
quotequote all
paua said:
Unnecessary or not, learn to do it anyway. It will make you a better driver - smoother & more mechanically sympathetic.
Exactly- I was trained to do this on my Police courses - certainly dont do it now and never did in my own cars - but as I said earlier makes for a lovely smooth down change when done properly

paua

5,687 posts

143 months

Thursday 22nd March 2018
quotequote all
Bigends said:
paua said:
Unnecessary or not, learn to do it anyway. It will make you a better driver - smoother & more mechanically sympathetic.
Exactly- I was trained to do this on my Police courses - certainly dont do it now and never did in my own cars - but as I said earlier makes for a lovely smooth down change when done properly
I've never done any sort of advanced training (opportunity), however I "learned" to drive a Ford Anglia, DDC wasn't Necessary, but made progress a lot smoother. Got to the point of not needing the clutch at all, after 1st. Current ( modernish) fun car has lightened singlemass flywheel, whilst DDC isn't "necessary" it certainly helps.

2 sMoKiN bArReLs

30,240 posts

235 months

Thursday 22nd March 2018
quotequote all
I drove around for a month with the clutch pedal of my Viva on the back seat. Even now I still find myself changing gear clutchless.

paua

5,687 posts

143 months

Thursday 22nd March 2018
quotequote all
akirk said:
DDC is not a bad skill to have and there are still cars on the road where it helps - it can also lead to a more leisurely and smoother transition...

however, as per my comments and Waremark's - in this scenario, as a first step it is not the correct answer
slow down earlier / less rapidly and the gear change will be easier

this is a classic example of the internal psychological pressure to maximise the road - meaning that the driver feels they need to brake as late as possible into a corner or they are losing progress - actually, braking earlier and separating the stages of the corner will give a smoother ride, and a better platform to allow acceleration out of the corner rather than fighting with brakes and gear changes in the corner - it is initially counter-intuitive, but when practised, becomes a much more fluid progress

so, simplest change is slow down!
Do you never need to change down to navigate a hill or pass a slower car? One doesn't want to slow, but rather, to maintain smooth momentum. DDC smoothes, even the most modern manual tranny

budgie smuggler

5,370 posts

159 months

Thursday 22nd March 2018
quotequote all
2 sMoKiN bArReLs said:
I drove around for a month with the clutch pedal of my Viva on the back seat. Even now I still find myself changing gear clutchless.
How did you get it into first gear to set off?

Kewy

1,462 posts

94 months

Thursday 22nd March 2018
quotequote all
I'm in a similar boat trying to refine my downshifts and heel & toe. Getting there slowly but its difficult to practice on the public road sometimes.

I use the blip technique, then again I'm learning it with a K20 so often downshifting into vtec at around 5-6k rpm.

2 sMoKiN bArReLs

30,240 posts

235 months

Thursday 22nd March 2018
quotequote all
budgie smuggler said:
2 sMoKiN bArReLs said:
I drove around for a month with the clutch pedal of my Viva on the back seat. Even now I still find myself changing gear clutchless.
How did you get it into first gear to set off?
Popped it in gear, then cranked the starter. Not so good in heavy stop start traffic! Reverse parking was a bit of a mare too. Frightened my mother to death!

akirk

5,385 posts

114 months

Thursday 22nd March 2018
quotequote all
paua said:
akirk said:
DDC is not a bad skill to have and there are still cars on the road where it helps - it can also lead to a more leisurely and smoother transition...

however, as per my comments and Waremark's - in this scenario, as a first step it is not the correct answer
slow down earlier / less rapidly and the gear change will be easier

this is a classic example of the internal psychological pressure to maximise the road - meaning that the driver feels they need to brake as late as possible into a corner or they are losing progress - actually, braking earlier and separating the stages of the corner will give a smoother ride, and a better platform to allow acceleration out of the corner rather than fighting with brakes and gear changes in the corner - it is initially counter-intuitive, but when practised, becomes a much more fluid progress

so, simplest change is slow down!
Do you never need to change down to navigate a hill or pass a slower car? One doesn't want to slow, but rather, to maintain smooth momentum. DDC smoothes, even the most modern manual tranny
yes - but then as per my first reply...
the issue with the scenario posted by the OP will be mainly resolved by slowing down and separating his braking and gear change - from the sound of it he is accelerating hard towards a corner, then slamming on the brakes / changing down from 5th to 3rd and complaining that he can't rev match because the revs are wildly different! He needs to slow the car down so that he doesn't become a part of the corner - then he can work on smoothness biggrin

DDC is a useful skill - but has very little to do with the OP's scenario - so my comment is focused on that - I can think of lots of scenarios where DDC is the right answer, but they weren't the question, so are irrelevant biggrin

budgie smuggler

5,370 posts

159 months

Thursday 22nd March 2018
quotequote all
2 sMoKiN bArReLs said:
Popped it in gear, then cranked the starter. Not so good in heavy stop start traffic! Reverse parking was a bit of a mare too. Frightened my mother to death!
rofl

Len Woodman

168 posts

113 months

Thursday 22nd March 2018
quotequote all
budgie smuggler said:
rofl
In 1979 at BSM we had a problem with the Minis where some component of the dual control clutch prevented clutch disengagement. As manager I had use of the spare car but gave it to instructors if needed. So, and it was usually at weekends, I often ended up with one of these Minis whilst the instructor got my Dolomite. Such was the lack of experience of all the instructors, who were all older than me, that they could not work out how I could drive without the clutch. Similar thing happened with the Metros.

The 'jump-start' process doesn't help in trucks - the clutch 'went' on my Bedford MK on the mountain road to Kathmandu in 1978. I had to plan and time every passing movement so that I never stopped for about 40 miles, coasting to a stop at a workshop in Pokhara that had an old Gurkha Bedford sitting outside.

Adamxck

1,212 posts

181 months

Friday 23rd March 2018
quotequote all
akirk said:
practise on a straight where you can go e.g. 5-4-5-4-5-4-5-4 - you should be able to do it eventually with no noticeable difference
I like this suggestion, though I'd add 3rd too. so 5-4-3-4-5-4-3 etc. Start with one gear at a time; you can block shift once you've nailed a single gear.
Choose a speed where 3rd gear is 4-4.5k rpm so you will have to confidently raise the revs. Being timid with the throttle will only result in a lumpy change. Just build your confidence slowly.

The key for me was to practice somewhere that you dont need to do it, like a long straight with nobody behind. The pressure to get it done before the corner comes off and your only goal is to rev match, so isolates the skill. Then start picking points where you want it done by, like a lampost or hedge. Then once you can time that right, make that point a corner and you'll be golden.


Dr Jekyll

23,820 posts

261 months

Friday 23rd March 2018
quotequote all
Try briefly pausing in neutral during the downchange. This gives a good opportunity for a throttle blip, if you overdo it just wait a bit longer for the revs to drop. Too little blip is a problem, too much can be sorted out with timing.

It's also a good half way to DDC. Once you get used to pausing, declutching and reclutching during the pause is straightforward.

I blip because that's how I was taught, but I've been told since that sustained throttle is preferable because once you get the hang of it little modification is required for different cars.