Brake gear overlap and tiptronics

Brake gear overlap and tiptronics

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Discussion

wiliferus

Original Poster:

4,053 posts

197 months

Tuesday 18th August 2020
quotequote all
I’ve driven to the ‘the system’ for the last 20 years or so.
Approaching a bend, set your speed then select the appropriate gear. No issues at all.

However, more and more cars now are tiptronic, flappy paddle autos. When driving a manual the system makes total sense, but with tiptronics you can’t do a 5th to 3rd change for example. You have to 5,4,3. As such, with regards to the system and tiptronics, bearing in mind you don’t have a clutch to worry about, is brake gear overlap acceptable, as it seems to make sense?

NDNDNDND

2,001 posts

182 months

Tuesday 18th August 2020
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vonhosen

40,198 posts

216 months

Tuesday 18th August 2020
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Gunnery Sgt Thomas Highway said:
You adapt, improvise, overcome.

Len Woodman

168 posts

112 months

Tuesday 18th August 2020
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Check Reg Local's thread.

wiliferus

Original Poster:

4,053 posts

197 months

Tuesday 18th August 2020
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Len Woodman said:
Check Reg Local's thread.
Nicely done, just what I was after. Thank you .

DocSteve

718 posts

221 months

Wednesday 19th August 2020
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Thanks Reg, these are useful.

One thing I would say is that you mention the rev matching function in the manual M2C and appear to cite this as a "permission" to BGOL. The arguments I've heard to date against BGOL as part of the classical AD system have never included the need to heel and toe. I might be taking this out of context but I do think that either BGOL should be avoided at almost all costs on the public road or, in fact, there should be an open acknowledgement from the AD community that it has its place, especially when the focus is on safe performance driving.

Separately, the lack of ability to turn off rev matching on modern manual M cars without entirely disabling the DSC is an issue some of my enthusiast colleagues have taken great issue with.

I am more on the fence than some when it comes to manual vs good dual clutch systems. I don't find the third pedal adds that much more involvement for me apart from H&T and if that is removed then even less. I often get flamed for making such comments...

Lastly, I think the modern ZF autos are so responsive the "sluggishness" described in taking up drive when time analogous to a manual change is not accounted for is not really a genuine issue.

Just my comments and find the videos very educational as well as provoking discussion points.

thebraketester

14,192 posts

137 months

Wednesday 19th August 2020
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wiliferus said:
is brake gear overlap acceptable, as it seems to make sense?
Yes.

Dizeee

18,168 posts

205 months

Wednesday 19th August 2020
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BGOL has always been acceptable when circumstances dictate. Often I find myself doing this local to me on a left turn, leaving a 40mph road to enter a small side road where the angle of entry and road width is narrow. If I slowed to the 10mph entry speed required, released the throttle, revved the engine and selected 1 / 2 gear, clutch up and then started to push pull my way in, it would ordinarily impinge on traffic behind and cause slowing, bunching and potentially annoyance.

Public expectation is key.

Ironically, I now drive a ZF8 paddled gearbox in my BMW, meaning I regularly have to brake and change down through the gears whilst doing so. It is just life, and what is required with my setup. I have no issues with it as there is no way round it.

DocSteve

718 posts

221 months

Wednesday 19th August 2020
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Dizeee said:
BGOL has always been acceptable when circumstances dictate. Often I find myself doing this local to me on a left turn, leaving a 40mph road to enter a small side road where the angle of entry and road width is narrow. If I slowed to the 10mph entry speed required, released the throttle, revved the engine and selected 1 / 2 gear, clutch up and then started to push pull my way in, it would ordinarily impinge on traffic behind and cause slowing, bunching and potentially annoyance.
I get this "exemption" to BGOL which is well described, but I am talking about performance driving where, for example, BGOL is used at higher speeds on the approach to an open bend. If, as Reg's video appears to suggest, the argument against this has previously been the ostensibly risky manoeuvre of H&T that can now be mitigated by modern rev matching technology then this opens up the debate more widely in my view.

dvenman

219 posts

114 months

Wednesday 19th August 2020
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DocSteve said:
ostensibly risky manoeuvre of H&T
Two things. Avoiding BGOL is really to avoid non-rev matched gear changes in normal use in a manual car or an auto with a crap gearbox and allows the driver to maintain smoothness and stability. I get why it's excepted in specific circumstances as described.

Secondly, H&T isn't "ostensibly risky". All it does is to allow braking to continue while allowing a simultaneous rev-matched gear change. It's not risky per se, it's if the operator doesn't know how or when to employ it properly, it'll detract from the drive.

surveyor_101

5,069 posts

178 months

Wednesday 19th August 2020
quotequote all
wiliferus said:
I’ve driven to the ‘the system’ for the last 20 years or so.
Approaching a bend, set your speed then select the appropriate gear. No issues at all.

However, more and more cars now are tiptronic, flappy paddle autos. When driving a manual the system makes total sense, but with tiptronics you can’t do a 5th to 3rd change for example. You have to 5,4,3. As such, with regards to the system and tiptronics, bearing in mind you don’t have a clutch to worry about, is brake gear overlap acceptable, as it seems to make sense?
Option A you leave the system in manual set your speed on the brake and then select the required gear prior to turn in and balance on the throttle (sport mode is often quicker to match gears to speed but it depends if the driving is spirited or relaxed)


Until June I had spent the last 9 months driving two company vehicles skoda DSG/ KIA DCT trans and had gotten used to running the in manual to gain advantage if needed and auto 80% of the time. These can be pushed down the gears pretty quick.

Then I have gone to my manual mazda and an auto saab 6 sentronic, the older is slower being dated CVT systems down shifting is much like the volvo gear tronic not a rushed affair. So I will normally only use the older auto in manual if I just want to drop one gear,

Option B leave in auto the system should select the appropriate gear for the speed/corner just avoid kick down in bends that you in ideal circumstances be used when the vehicle is pointing straight


Edited by surveyor_101 on Wednesday 19th August 11:04

waremark

3,241 posts

212 months

Wednesday 19th August 2020
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dvenman said:
Two things. Avoiding BGOL is really to avoid non-rev matched gear changes in normal use in a manual car or an auto with a crap gearbox and allows the driver to maintain smoothness and stability. I
I think it was originally promoted in the days when cars were less stable under braking to get drivers to keep two hands on the wheel during braking. It was promoted to me with the following benefits additional to being able to rev match while braking without needing H & T:

Both hands on wheel until slow
Braking earlier gives additional margin of safety
One thing to do at a time

I am unclear whether anyone teaches/requires separation in a manual car now.

I am very clear that using a paddle shift in manual mode with more than one gear to go down before a bend it is sensible to start changing down with overlap during braking.

On the manual/auto thing, the pleasure of a manual for me is mostly about rev matching accurately - and so is ruined by auto rev matching (I still make my best effort and beat myself up if I sense the auto system correcting what I have done). However a further pleasure comes from either using H & T or making time and space for separation before a hazard. I find it far more satisfying if slower and less efficient to drive a car with a clutch pedal.

surveyor_101

5,069 posts

178 months

Wednesday 19th August 2020
quotequote all
waremark said:
I think it was originally promoted in the days when cars were less stable under braking to get drivers to keep two hands on the wheel during braking. It was promoted to me with the following benefits additional to being able to rev match while braking without needing H & T:

Both hands on wheel until slow
Braking earlier gives additional margin of safety
One thing to do at a time

I am unclear whether anyone teaches/requires separation in a manual car now.

I am very clear that using a paddle shift in manual mode with more than one gear to go down before a bend it is sensible to start changing down with overlap during braking.

On the manual/auto thing, the pleasure of a manual for me is mostly about rev matching accurately - and so is ruined by auto rev matching (I still make my best effort and beat myself up if I sense the auto system correcting what I have done). However a further pleasure comes from either using H & T or making time and space for separation before a hazard. I find it far more satisfying if slower and less efficient to drive a car with a clutch pedal.
Having meet Chris Gilbert his view was whilst still good discipline, it dates back to decades ago when I cars had drums front and rear and braking and steering was not a good idea.


DocSteve

718 posts

221 months

Wednesday 19th August 2020
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dvenman said:
DocSteve said:
ostensibly risky manoeuvre of H&T
Two things. Avoiding BGOL is really to avoid non-rev matched gear changes in normal use in a manual car or an auto with a crap gearbox and allows the driver to maintain smoothness and stability. I get why it's excepted in specific circumstances as described.

Secondly, H&T isn't "ostensibly risky". All it does is to allow braking to continue while allowing a simultaneous rev-matched gear change. It's not risky per se, it's if the operator doesn't know how or when to employ it properly, it'll detract from the drive.
I used the word "ostensibly" carefully there... I don't think it is risky but I know some AD organisations, including RoSPA consider it to be unnecessary and potentially risky on the public road. I do not think it is risky if done properly - in fact, if you don't do it, especially in a powerful RWD car in the wet under heavy braking, you could risk locking up. But I think you know that!

waremark

3,241 posts

212 months

Wednesday 19th August 2020
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DocSteve said:
I don't think it is risky but I know some AD organisations, including RoSPA consider it to be unnecessary ......
Does anyone consider H&T necessary? Enjoyable, satisfying and can contribute to a smooth flowing drive yes, but necessary no. The Rospa approach for the situations where Roadcraft endorses overlap of braking and gear changing (eg downhill sharp bend) is to let the clutch out without rev matching but towards the end of braking at low engine revs - in which case even an old Lamborghini would not be thrown off the road (refers to a particular accident some of us heard about).

I can believe that risk is increased rather than reduced in the early learning stages. I recommend early practice while not trying to drive quickly into bends - and prioritising on the braking rather than the rev match.

DocSteve

718 posts

221 months

Friday 28th August 2020
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waremark said:
DocSteve said:
I don't think it is risky but I know some AD organisations, including RoSPA consider it to be unnecessary ......
Does anyone consider H&T necessary? Enjoyable, satisfying and can contribute to a smooth flowing drive yes, but necessary no. The Rospa approach for the situations where Roadcraft endorses overlap of braking and gear changing (eg downhill sharp bend) is to let the clutch out without rev matching but towards the end of braking at low engine revs - in which case even an old Lamborghini would not be thrown off the road (refers to a particular accident some of us heard about).

I can believe that risk is increased rather than reduced in the early learning stages. I recommend early practice while not trying to drive quickly into bends - and prioritising on the braking rather than the rev match.
I think this is all very reasonable. I also think H&T is necessary in some circumstances (car, speed and available grip all contributing) and it shouldn't be shunned by advocates of advanced road driving.

PhilAsia

3,697 posts

74 months

Friday 28th August 2020
quotequote all
DocSteve said:
waremark said:
DocSteve said:
I don't think it is risky but I know some AD organisations, including RoSPA consider it to be unnecessary ......
Does anyone consider H&T necessary? Enjoyable, satisfying and can contribute to a smooth flowing drive yes, but necessary no. The Rospa approach for the situations where Roadcraft endorses overlap of braking and gear changing (eg downhill sharp bend) is to let the clutch out without rev matching but towards the end of braking at low engine revs - in which case even an old Lamborghini would not be thrown off the road (refers to a particular accident some of us heard about).

I can believe that risk is increased rather than reduced in the early learning stages. I recommend early practice while not trying to drive quickly into bends - and prioritising on the braking rather than the rev match.
I think this is all very reasonable. I also think H&T is necessary in some circumstances (car, speed and available grip all contributing) and it shouldn't be shunned by advocates of advanced road driving.
I think it boils down to skill level and situational awareness.

Separation of controls is a great way to get people to a reasonable level of competence with dialled in safety.

Paddle shifts allow BGOL to be entered into safely.

H & T can be fluffed and still remain in safe hands eg. Senna at Monaco on one of his famous laps. Fluffed the H&T change and went through the corner in neutral.




















Salted_Peanut

1,359 posts

53 months

Sunday 30th August 2020
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PhilAsia said:
Separation of controls is a great way to get people to a reasonable level of competence with dialled in safety.
It is. But the problem is when the means (avoiding BGOL) becomes a goal in itself. And the excessive hoo-ha about BGOL will – with Tiptronic and electric cars – soon become extinct.

Salted_Peanut

1,359 posts

53 months

Sunday 30th August 2020
quotequote all
Incredibly, I've managed to ride a motorcycle for years without too many crashes caused by BGOL tongue out If it has its place on two advanced wheels, why not in AD?

Motorcycle Roadcraft said:
During the latter stages of braking change to the appropriate gear.
And this down-change typically uses the motorcycle equivalent of H&T: both applying the front brake and blipping the throttle with the right hand simultaneously. As used by cop