Modern gearing + BGOL
Discussion
Nigel_O said:
most modern turbo diesels with a manual box have a short 1st gear, its designed just to get the thing moving - in mine, if I'm moving at anything more than a trickle (ie up to slow walking pace), I'll always use second gear to move away.
Just out of curiosity, what speed would peak power in 1st gear be? In mine, with a 6-speed box, it's about 25 mph. If I'm down to 10-15 mph, I often rev-match to 1st for a corner.Nigel_O said:
By comparison, in my turbo-nutter car, 1st is good for well over 40, but it really doesn't like selecting 1st while its moving (draggy motorsport clutch) - if I could actually select 1st gear, I'd probably use it to accelerate even if I was doing 15-ish mph.
Isn't it normally just a question of rev-matching properly?AnotherGareth said:
Isn't it normally just a question of rev-matching properly?
Not always. Some boxes resist changes to 1st irrespective of rev matching. The 997 box is an example. It's a well known 'characteristic'.A 10mph bend must be pretty bloody sharp! I can't remember the last time I used 1st gear for a corner.
The gearbox being reluctant to select first when moving, but accepting a change to first easily when the vehicle's stationary, is presumably caused by the additional work that the synchromesh has to do when the vehicle's moving. On that basis, more accurate rev-matching and, even better, double-declutching can only help matters, I should have thought.
9xxNick said:
The gearbox being reluctant to select first when moving, but accepting a change to first easily when the vehicle's stationary, is presumably caused by the additional work that the synchromesh has to do when the vehicle's moving. On that basis, more accurate rev-matching and, even better, double-declutching can only help matters, I should have thought.
Helps. But the box still does what it wants. Not the only car that I've had with that characteristic. Also sometimes reluctant from a standstill. 9xxNick said:
I'm not entirely disagreeing with some boxes being a bit resistant to selecting first, and indeed some Alfa boxes were notorious for it in the 60s, but I do think quite a lot of the problem is that the synchromesh is being asked to do a lot of work on occasion.
Yep. But that's not the case with the 997 box. It's just a very temperamental gear. Rev matching makes no difference, but double de-clutching does, as does moving the gear lever into 2nd, clutch still down, and then into 1st. ORD said:
It's just a very temperamental gear. Rev matching makes no difference, but double de-clutching does, as does moving the gear lever into 2nd, clutch still down, and then into 1st.
The latter point is the same as with the older Alfa 5-speed gearbox - it's a real PITA trying to get into 1st when the car isn't moving, more so when the gearbox is cold. However that's a case in point where accurate rev-matching allows selecting 1st but it will baulk if slightly off with the engine speed.The main reason I no longer overlap brakes and gears is that it forces you to look further ahead, which allows much more time to assess what's happening, plan appropriately, get the position and speed right - then, a relaxed, smooth, unhurried gear change up or down the box (one or more gears at a time, I'm not fussy, and only changing gear if I need to) lets me negotiate a hazard in the right gear to use the appropriate amount of acceleration the other side of it.
This to me is the essence - not BGOL'ing forces you to plan much further ahead, and making only one gear change avoids multiple chances to make a crap gear change
If you've always used a particular method or approach then fine - but from a personal perspective, I'd rather one smooth block change than lots (I'm lazy) and long term it will reduce wear and tear on all the bits between my foot and the clutch.
And one last thing - if someone shows me something which works to smoothen out my driving, if it works for me, I'll adopt it !
This to me is the essence - not BGOL'ing forces you to plan much further ahead, and making only one gear change avoids multiple chances to make a crap gear change
If you've always used a particular method or approach then fine - but from a personal perspective, I'd rather one smooth block change than lots (I'm lazy) and long term it will reduce wear and tear on all the bits between my foot and the clutch.
And one last thing - if someone shows me something which works to smoothen out my driving, if it works for me, I'll adopt it !
You can look far ahead and still mix braking and changing gear. You just benefit from being able to put off your braking until a bit later, which means that you dont scrub off speed unnecessarily. If I want to be off the brakes before changing down for a roundabout, I have to finish my braking in time to allow both the "go or stop" decision and a gear change. If, by contrast, I heel and toe the change, I can be braking right up to the decision point. I may be an idiot, but I always seem to scrub off more speed than I want to if I am braking and know that I need to get that done before changing gear
I sometimes adopt a completely different approach (usually when not driving for fun) and take an intermediate gear very early, use a bit of engine braking and accept that I am probably going a bit more slowly than the hazard would allow but will brake less hard and make smoother progress. I never hold anyone adopting that approach either, as most people drive very slowly except on open stretches of road (where they go mental).
I sometimes adopt a completely different approach (usually when not driving for fun) and take an intermediate gear very early, use a bit of engine braking and accept that I am probably going a bit more slowly than the hazard would allow but will brake less hard and make smoother progress. I never hold anyone adopting that approach either, as most people drive very slowly except on open stretches of road (where they go mental).
AnotherGareth said:
Isn't it normally just a question of rev-matching properly?
Rev-matching makes it easier to go into 1st while rolling, but not by much - regardless of rev matching its a nasty box at walking pace or below. Its also recalcitrant going into 1st at a standstill, so if I know I'm going to pull away in less than a few seconds, I try to select 1st just before coming to a stop, otherwise I'm faced with having to give the gearlever a really hard shove. If I'm going to be waiting more than a few seconds, I have to select neutral simply to preserve the clutch and my left legOn the Alfa, I wouldn't dare try to select 1st while doing 10-15mph - the noise would be horrible - four-pot diesels really don't sound good when they're being revved to the redline, especially in the lower gears. To do it while off the throttle would involve a serious lack of mechanical sympathy. Heck - at 10-15mph, its a toss-up between going for second or leaving it in third....
Pontoneer said:
I recall a certain satisfaction resulting from double declutching into first if rolling up to a junction in my Triumph Herald with non synchro first gear
Yes indeed. I've never driven a Triumph Herald, but I do have experience of other cars of that era, and it was very pleasing to get it right when engaging 1st gear while on the move.Moving on to something a bit younger, with our pug 406 HDi I can roll along at 5 mph, declutch, engage 1st gear then come straight off the clutch pedal, and the car will roll along at idling speed in 1st gear.
Nigel_O said:
On the Alfa, I wouldn't dare try to select 1st while doing 10-15mph - the noise would be horrible - four-pot diesels really don't sound good when they're being revved to the redline
I'm trying to understand where you're coming from; how much of what you say is real and how much is hyperbole. It would help if you say what speed peak power in 1st gear would be. I suspect it's likely to be well above 10-15 mph, in which case 10-15 mph would be nowhere near the red line.ORD said:
I guess the answer is that the only downsides of separation are that it maybe makes you a bit slower and means braking earlier. And neither is a bad thing for road driving.
I'm not disagreeing with you with regard to slowing some drivers down but does BGOL cause issues for everyone who does it (planned or not)? Seems to me that this whole PP steering and BGOL thing has escalated via two driving organisations insisting upon it, because they use Police driving instructors or examiners for their tests and because they use 'The Police Driver's Handbook' as a textbook; the textbook evolved due to the inordinately high numbers of Police drivers crashing. Civilian drivers do not have the same needs as Police drivers, so there's one argument against insisting on BGOL from every civvy driver. There are others...For me, BGOL forces people who've not thought about systematic driving before to put a pause in between the phases of The System. If you're using acceleration sense as well, then for some situations you don't need to brake, so that removes the B, you just need (perhaps) to change to an appropriate gear for the hazard.
Unless you heel-and-toe or use some other mechanism to match road and engine RPMs then a gearchange can be a tad jerky, but if you slow down enough then it does become a non-issue.
There's a wider discussion on another forum I follow about, almost, the Zen of driving - does it matter as long as you're safe and smooth what method you use ? Not really, in the long run, but beginners need to hang their hat on something to start with...
Unless you heel-and-toe or use some other mechanism to match road and engine RPMs then a gearchange can be a tad jerky, but if you slow down enough then it does become a non-issue.
There's a wider discussion on another forum I follow about, almost, the Zen of driving - does it matter as long as you're safe and smooth what method you use ? Not really, in the long run, but beginners need to hang their hat on something to start with...
Edited by dvenman on Monday 7th September 13:32
dvenman said:
For me, BGOL forces people who've not thought about systematic driving before to put a pause in between the phases of The System. If you're using acceleration sense as well, then for some situations you don't need to brake, so that removes the B, you just need (perhaps) to change to an appropriate gear for the hazard.
Unless you heel-and-toe or use some other mechanism to match road and engine RPMs then a gearchange can be a tad jerky, but if you slow down enough then it does become a non-issue.
There's a wider discussion on another forum I follow about, almost, the Zen of driving - does it matter as long as you're safe and smooth what method you use ? Not really, in the long run, but beginners need to hang their hat on something to start with...
I agree. It is a very sensible system for most drivers, but it should be seen as just that and not the ultimate in good road driving. Unless you heel-and-toe or use some other mechanism to match road and engine RPMs then a gearchange can be a tad jerky, but if you slow down enough then it does become a non-issue.
There's a wider discussion on another forum I follow about, almost, the Zen of driving - does it matter as long as you're safe and smooth what method you use ? Not really, in the long run, but beginners need to hang their hat on something to start with...
Edited by dvenman on Monday 7th September 13:32
You have to rev-match even if you separate braking and gear change, unless you want to change down out of the power band. This is why I heel and toe when I am driving quickly - if I am going to rev-match by blipping, I may as well do so while braking; if I am pootling along at low revs, then I'll let the clutch do more of the work and keep the revs low enough that I dont need to blip the throttle at all but just gently increase the pressure at the clutch comes up. Someone will probably tell me that's bad for the clutch, but I have never worn out a clutch yet.
Putting 'the system' aside for a moment, does it matter if a driver cannot rev match and control the car to the Nth degree of smoothness? Again, I'd say that unless there is something distinctly dangerous about what effect their inputs have on the overall output, why interfere with it? This is why advanced driving (pick a description of your choice) has always been a minority pursuit.
Observe any 30mph road where traffic has to slow and speed up and count how many cars crash, nearly crash, swerve to avoid etc. I think the outcome will be a very long wait. You could easily place any template over a driver's technique and criticise it to pieces but unless they are doing something awful on the road, what's the point? Human are excellent at adapting technique until it works for them and just because it may not conform to a system, doesn't necessarily make it wrong or bad. I think most drivers would feel incredibly patronised if they were told that despite zero claims over many years, that they're holding a wheel wrongly or braking while changing gear dangerously just because a system says so.
What we need are thinking drivers, not pattern matchers.
Observe any 30mph road where traffic has to slow and speed up and count how many cars crash, nearly crash, swerve to avoid etc. I think the outcome will be a very long wait. You could easily place any template over a driver's technique and criticise it to pieces but unless they are doing something awful on the road, what's the point? Human are excellent at adapting technique until it works for them and just because it may not conform to a system, doesn't necessarily make it wrong or bad. I think most drivers would feel incredibly patronised if they were told that despite zero claims over many years, that they're holding a wheel wrongly or braking while changing gear dangerously just because a system says so.
What we need are thinking drivers, not pattern matchers.
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