using clutch to control car speed going down steep hill

using clutch to control car speed going down steep hill

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GetCarter

29,358 posts

278 months

Wednesday 29th July 2015
quotequote all
sdyson31 said:
Thank you for everyones reply.

Today I drove for four hours, I didn't use the clutch uphill or downhill, and it went very well.

For a very steep hill, I will always use second gear, and will use first gear if its a steep hill, as soon as I move off. For example if I am coming out of a car park and theres a very steep hill, like the one in st ives.
I'll repeat this as it'll be the best motoring money you'll ever spend

O/P ... book yourself a couple of hours with http://www.cadence.co.uk - you'll learn more in those hours than you did in all your lessons put together.

gavsdavs

1,203 posts

125 months

Wednesday 29th July 2015
quotequote all
DonkeyApple said:
You aren't listening. Only you are talking about slamming down gears as you have not read what I have written.
Okay. So lets go back to your original comment
DonkeyApple said:
Yup. But always worth bearing in mind that with a rwd car you are applying braking only on the rear wheels, just like applying the handbrake. And when people abuse engine braking they can get a little bit of a surprise.

Interestingly, it seems quite a common issue when people who have spent years ragging fwd cars switch to a performance RWD car and then wonder what the juddering fk has just happened as they drift backwards over a roundabout. biggrin

I recall watching a chap in a TVR coming down Fish Hill in the Cotswolds in the wet. He was holding a lower gear all the way down and using engine braking to help control speed, as all of is would in manuals, except when he got into the right hand bend towards the bottom off he went up the grass backwards.
Key words in here "a chap in a TVR coming down Fish Hill in the Cotswolds in the wet".

okay. what do we know about TVRs. Big V8; probably a lightened flywheel; not a lot of weight over some very wide (possibly summer) rear tyes; Water on surface of road; I am not familiar with Fish Hill. Sounds treacherous already.

DonkeyApple said:
I am talking about exactly the same situation as you. Just simy coming down a slope at a perfectly sensible pace and using engine braking as part of your means of maintaining a suitable speed and controlling it.

It is really very simple. Under engine braking conditions you are only braking with the driven wheels. There is a very good reason why brakes work on all wheels. RWD is obviously less forgiving than FWD. Again for really rather obvious reasons.
So you've seen it happen, in circumstances that make it more likely, but you weren't actually in the car to see the drivers actions.

Please put it down to circumstances. It's not commonplace.


HustleRussell

24,602 posts

159 months

Wednesday 29th July 2015
quotequote all
DonkeyApple said:
HustleRussell said:
Why is it that on PistonHeads we have so many of these "I'm right and those who disagree with me simply don't comprehend" types. It's quite tiresome.
So you think there is no risk to rear wheel braking alone? Bon chance. biggrin
You might consider reading my already posted stance on this rather than making it up yourself. I doubt it though.

DonkeyApple

54,923 posts

168 months

Wednesday 29th July 2015
quotequote all
gavsdavs said:
DonkeyApple said:
You aren't listening. Only you are talking about slamming down gears as you have not read what I have written.
Okay. So lets go back to your original comment
DonkeyApple said:
Yup. But always worth bearing in mind that with a rwd car you are applying braking only on the rear wheels, just like applying the handbrake. And when people abuse engine braking they can get a little bit of a surprise.

Interestingly, it seems quite a common issue when people who have spent years ragging fwd cars switch to a performance RWD car and then wonder what the juddering fk has just happened as they drift backwards over a roundabout. biggrin

I recall watching a chap in a TVR coming down Fish Hill in the Cotswolds in the wet. He was holding a lower gear all the way down and using engine braking to help control speed, as all of is would in manuals, except when he got into the right hand bend towards the bottom off he went up the grass backwards.
Key words in here "a chap in a TVR coming down Fish Hill in the Cotswolds in the wet".

okay. what do we know about TVRs. Big V8; probably a lightened flywheel; not a lot of weight over some very wide (possibly summer) rear tyes; Water on surface of road; I am not familiar with Fish Hill. Sounds treacherous already.

DonkeyApple said:
I am talking about exactly the same situation as you. Just simy coming down a slope at a perfectly sensible pace and using engine braking as part of your means of maintaining a suitable speed and controlling it.

It is really very simple. Under engine braking conditions you are only braking with the driven wheels. There is a very good reason why brakes work on all wheels. RWD is obviously less forgiving than FWD. Again for really rather obvious reasons.
So you've seen it happen, in circumstances that make it more likely, but you weren't actually in the car to see the drivers actions.

Please put it down to circumstances. It's not commonplace.
Exactly. 100%. The laws of physics don't change. And that is precisely why I raised it as something people should keep in mind when using engine braking to moderate their descent. It isn't a risk free action. Most people fail to appreciate this. So no need for people's sarky remarks.

DonkeyApple

54,923 posts

168 months

Wednesday 29th July 2015
quotequote all
HustleRussell said:
DonkeyApple said:
HustleRussell said:
Why is it that on PistonHeads we have so many of these "I'm right and those who disagree with me simply don't comprehend" types. It's quite tiresome.
So you think there is no risk to rear wheel braking alone? Bon chance. biggrin
You might consider reading my already posted stance on this rather than making it up yourself. I doubt it though.
Then why make a smug remark if you agree?

greypianosflying

86 posts

153 months

Wednesday 29th July 2015
quotequote all
I truly despise the phrase "gears to go, brakes to slow". (Any many other over simplified driving rules).

On my commute home I go down a long relatively steep hill for a couple of miles. In fifth my car runs away, so I do a small blip of the throttle, shift into fourth (using about 0.000000001% of the clutch friction material) and continue down the entire hill with zero throttle at 60mph. Brake wear zero.

Other road uses, who must be "gears to go, brakes to slow" followers stay in fifth and mash repeatedly for 2 miles.

Why on earth would I wear out my brakes (significant if done every single day), when I can just down shift? I see this brake on, brake off, brake on driving style every day and it is (in my opinion) crap driving. It's also bloody annoying to be behind someone doing this!


HustleRussell

24,602 posts

159 months

Wednesday 29th July 2015
quotequote all
DonkeyApple said:
HustleRussell said:
DonkeyApple said:
HustleRussell said:
Why is it that on PistonHeads we have so many of these "I'm right and those who disagree with me simply don't comprehend" types. It's quite tiresome.
So you think there is no risk to rear wheel braking alone? Bon chance. biggrin
You might consider reading my already posted stance on this rather than making it up yourself. I doubt it though.
Then why make a smug remark if you agree?
I don't agree. You seem to be trying to convince everyone that engine braking will result in some catastrophic loss of control.

DonkeyApple

54,923 posts

168 months

Thursday 30th July 2015
quotequote all
HustleRussell said:
DonkeyApple said:
HustleRussell said:
DonkeyApple said:
HustleRussell said:
Why is it that on PistonHeads we have so many of these "I'm right and those who disagree with me simply don't comprehend" types. It's quite tiresome.
So you think there is no risk to rear wheel braking alone? Bon chance. biggrin
You might consider reading my already posted stance on this rather than making it up yourself. I doubt it though.
Then why make a smug remark if you agree?
I don't agree. You seem to be trying to convince everyone that engine braking will result in some catastrophic loss of control.
Really? You get all pissy and priggy and then smugly instruct me to read your original points and then come out with that!!! You are an analphabetic fking idiot. rofl

gavsdavs

1,203 posts

125 months

Thursday 30th July 2015
quotequote all
DonkeyApple said:
Really? You get all pissy and priggy and then smugly instruct me to read your original points and then come out with that!!! You are an analphabetic fking idiot. rofl
Give over with the industrial english, will ya ?

To be honest, I sort of agree with others. There isn't really a risk to using engine braking. You've seen something bad happen once, in a scenario where its most likely to happen, but if I want to do it, I f*cking well will. It's my risk, I'll take it thank you very much. Please don't make out like it's going to happen every time and should be avoided, because we all drive differently.

Relax dude.

DonkeyApple

54,923 posts

168 months

Thursday 30th July 2015
quotequote all
gavsdavs said:
DonkeyApple said:
Really? You get all pissy and priggy and then smugly instruct me to read your original points and then come out with that!!! You are an analphabetic fking idiot. rofl
Give over with the industrial english, will ya ?

To be honest, I sort of agree with others. There isn't really a risk to using engine braking. You've seen something bad happen once, in a scenario where its most likely to happen, but if I want to do it, I f*cking well will. It's my risk, I'll take it thank you very much. Please don't make out like it's going to happen every time and should be avoided, because we all drive differently.

Relax dude.
Please go and read what I originally wrote and you will see that this is exactly what I was saying and that you are actually responding to a total misunderstanding of someone else.

You are right. There isn't really a risk of you are changing down sensibly and also using brakes appropriately. I agree with you and others and have done from the outset. At the same time, by your use of 'really' you are clearly aware that there is an element of risk in some situations. Exactly the same as I was acknowledging.

The point of my original post was simply to highlight that people should be aware that there is an element of risk as this thread has shown, large numbers of drivers are totally oblivious.

It is also a little more important than one might at first consider as most people who migrate onto high powered, light RWD cars have spent much of their driving life in very forgiving conventional road cars. What was absolutely fine in a conventional car suddenly gets highlighted as a bad habit. Hence the chap in the Tuscan gracefully sliding up the verge backwards. He had not appreciated that he was entering a gentle corner while effectively having the equivalent of the hand brake on.

Go to an experience driving day or the Ring and it is extremely common to see engine braking on turn in (this isn't the snatching down the gears before anyone leaps into that spurious band wagon again!) and the resultant spin.

No road is truly straight or truly even and the laws of physics do not deviate from one type of car to the next. Ergo, being aware of the potential impact of applying braking force to only the driven wheels should be clear to all drivers.

Stickyfinger

8,429 posts

104 months

Thursday 30th July 2015
quotequote all
Stop now pls....you are all repeating
https://www.youtube.com/watch?v=szrof4WJsKw

DonkeyApple

54,923 posts

168 months

Thursday 30th July 2015
quotequote all
Stickyfinger said:
Stop now pls....you are all repeating
https://www.youtube.com/watch?v=szrof4WJsKw
You are right.

HustleRussell

24,602 posts

159 months

Thursday 30th July 2015
quotequote all
hehe you lost me at "equivalent of the handbrake"

gavsdavs

1,203 posts

125 months

Thursday 30th July 2015
quotequote all
DonkeyApple said:
Go to an experience driving day or the Ring and it is extremely common to see engine braking on turn in (this isn't the snatching down the gears before anyone leaps into that spurious band wagon again!) and the resultant spin.
I just think you're misattributing the spin to engine braking causing it. Too much entry speed, too much lock and then maybe some brakes, yes, a car will spin (my car loves to do that). It's not engine braking that's spinning the car, it's the excessive entry speed and lock used for the grip available.

For normal road use, cars spinning due to excessive engine braking just doesn't happen. Engine braking isn't as strong a force as applying the handbrake (in a roadgoing vehicle).

DonkeyApple

54,923 posts

168 months

Thursday 30th July 2015
quotequote all
gavsdavs said:
For normal road use, cars spinning due to excessive engine braking just doesn't happen. Engine braking isn't as strong a force as applying the handbrake (in a roadgoing vehicle).
On a RWD car there is absolutely no difference between the two actions. Both are applying braking force only to the driven wheels and the same laws of physics apply to both.

I'm genuinely interested in how you think otherwise? I'm sure you wouldn't advocate slowing a hill descent by pulling the handbrake up a notch to apply braking to the rear wheels so why is it suddenly 100% fine to do the same using the gearbox?

I'm intrigued as to how such action can be argued to be risk free as appears to be mooted? Or, for that matter, why cars traditionally have a braking bias to the front wheels? Or why matching revs has any place?

HustleRussell

24,602 posts

159 months

Thursday 30th July 2015
quotequote all
How do you suppose a wheel is going to lock if it is connected by the drivetrain to a running engine?

The engine braking / handbrake comparison is a bum steer.

If you were on a low grip surface and you very abruptly downshifted into entirely the wrong gear you could under-rotate the driven wheels. It's not a risk that'd occur to your average driver. It's only happened to me when I was messing about on snow / ice.

Edited by HustleRussell on Thursday 30th July 11:56

DonkeyApple

54,923 posts

168 months

Thursday 30th July 2015
quotequote all
What has wheel locking got to do with anything at all?

What we are talking about is the negative attributes of only applying a braking force, in any guise, to the driven wheels alone.

HustleRussell

24,602 posts

159 months

Thursday 30th July 2015
quotequote all
Applying the handbrake carries a risk of locking the wheel(s). That's why your comparing engine braking to applying the handbrake is a bum steer.

DonkeyApple

54,923 posts

168 months

Thursday 30th July 2015
quotequote all
HustleRussell said:
Applying the handbrake carries a risk of locking the wheel(s). That's why your comparing engine braking to applying the handbrake is a bum steer.
There is absolutely no difference between the two. Seriously, think it through. We aren't talking about absolute forces but the application of a force. And the two means of applying that force are absolutely identical in their result.

Besides which, what has locking a wheel got to do with this? Are you implying that it is only under locked wheels that car becomes unsettled?

HustleRussell

24,602 posts

159 months

Thursday 30th July 2015
quotequote all
I'm beginning to think my time is wasted trying to discuss this with somebody who thinks engine braking and applying the handbrake are the same thing.

'Seriously, think it through'