The Automatic Gearbox And Its Failings
Discussion
Sump said:
You don't know how to drive with an auto.
use the throttle to control all the gear changes. It's very simple actually.
This^^.use the throttle to control all the gear changes. It's very simple actually.
Mr Will said:
I'd echo this. After a while with a particular autobox you learn how far you need to press the pedal to get it to shift down, or where to hold it to prevent unwanted upshifts. A quick blip/lift then returning to the original position can work wonders. You do need to learn the car though, rather than attempting to force it to bend to your will.
And this^^.Driving an auto is as much of a skill as driving a manual.
My first car (1972) was a Mini Clubman Estate with an autobox - 'J' reg (1971) & it was almost new.
Unusually all 4 gears were selectable on the lever. Pootling around in 'D' was normal but if you wanted to play then select first, floor the throttle & move the selector lever at appropriate moments keeping the pedal on the floor.
Surprised more than a few traffic light Grand Prixers (OK so I was 18 & daft!
)
I've driven a few autos since & my current Range Rover Classic is an auto (4 speed ZF) & with every one you can either stick it in 'D' & hope for the best or drive it.
An auto can be better offroad & not unusual to see serious trials Land Rovers with autoboxes.
ETA The Bowler EXR S is a six speed auto. http://www.bowlermotorsport.com/portfolio/bowler-e...
Unusually all 4 gears were selectable on the lever. Pootling around in 'D' was normal but if you wanted to play then select first, floor the throttle & move the selector lever at appropriate moments keeping the pedal on the floor.
Surprised more than a few traffic light Grand Prixers (OK so I was 18 & daft!
)I've driven a few autos since & my current Range Rover Classic is an auto (4 speed ZF) & with every one you can either stick it in 'D' & hope for the best or drive it.
An auto can be better offroad & not unusual to see serious trials Land Rovers with autoboxes.
ETA The Bowler EXR S is a six speed auto. http://www.bowlermotorsport.com/portfolio/bowler-e...
Edited by paintman on Thursday 17th July 09:25
DonkeyApple said:
cerb4.5lee said:
TurboHatchback said:
There are good and bad boxes of course, bad ones are really obviously bad but good ones should be unnoticeable in their operation. I think that torque converter autos only work well with really torquey engines, either diesels or 4.0l+ petrols.
I think this hits the nail on the head and makes sense why the ZF slushbox doesn't work in my 330i very well and is a bad gearbox as the engine doesn't have much torque and it only has a relatively small capacity but as with anything you don't know until you try it and in our old 330d it seemed to worked a treat because of the torque and short powerband.I've been working on a gearbox conversion to fit a modern box into a classic car and have learnt quite a bit about how to install these types of boxes and get them to work properly. Obviously in OEM guise the TCU talks openly with the ECU and this allows torque management for smoother changes and the changing of line pressures based on engine criteria, rpm, throttle position and much more.
What I have noticed is that it takes hundreds of man hours to calibrate and tune the TCU for a specific application. It doesn't take many hours to get a lovely, smooth, predictable shift in normal driving conditions but it takes a massive amount of time to map each of the less common driving scenarios.
If we look at BMW, the ZF6 works wonderfully in their 3 series diesels, 5 and 7 series but the same unit is a bit of a turd in comparison in the 3.0 petrol small cars. If we then look at the classifieds I think we suddenly see the answer. BMW will sell nigh on 1m 3 series diesel autos, almost every 5 series will be an auto and diesel and all 7s are autos. In contrast they will only ever sell a few thousand 130 autos (none currently on PH and about 2 in AutoTrader) and still only ever sell a small number of 330 autos in relation to other models.
I think that because they know they will sell bugger all of these combos that they do not invest the hours in tuning the box to match the specific car. My guess is that they take the TCU map from a 5 Series petrol 6 or maybe even a 3 series diesel and just fine tune, re calibrate the basic everyday conditions in a few hours and leave the complex tuning as it wouldn't be profit efficient for the number of units they will sell.
However, a couple of the OPs issues are really down to driver misjudgement. The box can't predict the road ahead (apart from in a Rolls) it can only read the current data and make a descision. There are times when you know that these conditions are going to change quicker than the box can work out so you have to take control. Joining slip roads off roundabouts going uphill is a classic. You know exactly what is about to happen and what needs to be done but the gearbox has no data on how long the corner is, how steep the gradient is or that you now need to go from 30 to 70. It knows non of this and so you must take control by starting your exit from the apex by putting the car in the right gear yourself. So typically that means manually notching down a gear or two to find the bottom of the torque curve going into the start of the corner etc.
I find you don't notice how good an auto box is, you just notice the bad ones, the Dodge Minivan I had in the states was hilarious, bad pairing of a fairly peaky V6, a heavy car and auto box that didnt really know what was going on, I get the changing gear using the throttle but you had to be so bloody direct with it, then it would change down two gears and wake everybody up.
I don't do enough miles for an manual to get on my nerves, would love to try one of the more recent 8 speeders or dual clutch jobs, the latter sounds like it is a good halfway house, I do like the rather robust clutch and gearchange in my 350Z but it is rather archaic, just wonder whether I would miss it if I go DSG next.
I don't do enough miles for an manual to get on my nerves, would love to try one of the more recent 8 speeders or dual clutch jobs, the latter sounds like it is a good halfway house, I do like the rather robust clutch and gearchange in my 350Z but it is rather archaic, just wonder whether I would miss it if I go DSG next.
cerb4.5lee said:
DonkeyApple said:
cerb4.5lee said:
TurboHatchback said:
There are good and bad boxes of course, bad ones are really obviously bad but good ones should be unnoticeable in their operation. I think that torque converter autos only work well with really torquey engines, either diesels or 4.0l+ petrols.
I think this hits the nail on the head and makes sense why the ZF slushbox doesn't work in my 330i very well and is a bad gearbox as the engine doesn't have much torque and it only has a relatively small capacity but as with anything you don't know until you try it and in our old 330d it seemed to worked a treat because of the torque and short powerband.I've been working on a gearbox conversion to fit a modern box into a classic car and have learnt quite a bit about how to install these types of boxes and get them to work properly. Obviously in OEM guise the TCU talks openly with the ECU and this allows torque management for smoother changes and the changing of line pressures based on engine criteria, rpm, throttle position and much more.
What I have noticed is that it takes hundreds of man hours to calibrate and tune the TCU for a specific application. It doesn't take many hours to get a lovely, smooth, predictable shift in normal driving conditions but it takes a massive amount of time to map each of the less common driving scenarios.
If we look at BMW, the ZF6 works wonderfully in their 3 series diesels, 5 and 7 series but the same unit is a bit of a turd in comparison in the 3.0 petrol small cars. If we then look at the classifieds I think we suddenly see the answer. BMW will sell nigh on 1m 3 series diesel autos, almost every 5 series will be an auto and diesel and all 7s are autos. In contrast they will only ever sell a few thousand 130 autos (none currently on PH and about 2 in AutoTrader) and still only ever sell a small number of 330 autos in relation to other models.
I think that because they know they will sell bugger all of these combos that they do not invest the hours in tuning the box to match the specific car. My guess is that they take the TCU map from a 5 Series petrol 6 or maybe even a 3 series diesel and just fine tune, re calibrate the basic everyday conditions in a few hours and leave the complex tuning as it wouldn't be profit efficient for the number of units they will sell.
However, a couple of the OPs issues are really down to driver misjudgement. The box can't predict the road ahead (apart from in a Rolls) it can only read the current data and make a descision. There are times when you know that these conditions are going to change quicker than the box can work out so you have to take control. Joining slip roads off roundabouts going uphill is a classic. You know exactly what is about to happen and what needs to be done but the gearbox has no data on how long the corner is, how steep the gradient is or that you now need to go from 30 to 70. It knows non of this and so you must take control by starting your exit from the apex by putting the car in the right gear yourself. So typically that means manually notching down a gear or two to find the bottom of the torque curve going into the start of the corner etc.
DonkeyApple said:
However, a couple of the OPs issues are really down to driver misjudgement. The box can't predict the road ahead (apart from in a Rolls) it can only read the current data and make a descision. There are times when you know that these conditions are going to change quicker than the box can work out so you have to take control. Joining slip roads off roundabouts going uphill is a classic. You know exactly what is about to happen and what needs to be done but the gearbox has no data on how long the corner is, how steep the gradient is or that you now need to go from 30 to 70. It knows non of this and so you must take control by starting your exit from the apex by putting the car in the right gear yourself. So typically that means manually notching down a gear or two to find the bottom of the torque curve going into the start of the corner etc.
Quite right. I think I get more frustrated by these things than other drivers might too, hence my post. I do use the manual shift quite often, but I find on my 12 mile commute that I'll slip the box into manual mode on probably 5 occasions in maybe 20 minutes of driving...which probably suggests that I should have chosen a manual as the auto isn't really suitable for my needs. Oh well, live and learn.wiliferus said:
The slush box in my 2.6 Omega needs to be controlled and driven. Stick it in D and just drive it wafts around and makes clumsy changes at inappropriate times.
If I use tactical use of the 'Sport' mode, it will hold the gear longer for sweeping bends or a series of corners. I even flick it into sport for bigger roundabouts so I don't get a mid junction change.
Often I'll use the stick to lock it into 2nd or 3rd on approaches to bends to get a smoother drive out, and then pop it back into D once I've cleared it.
It's all about how lazy you want to be and what you want the car to do.
Nice car - I had a 2.6 CDX Omega and its not a bad autobox at all. The trouble is the Car is just too darn heavy for the engine, admittedly its a sight better than the 4 cylinder cars but it needs quite a bit more than 180bhp with the autobox to not feel a little leaden. If I use tactical use of the 'Sport' mode, it will hold the gear longer for sweeping bends or a series of corners. I even flick it into sport for bigger roundabouts so I don't get a mid junction change.
Often I'll use the stick to lock it into 2nd or 3rd on approaches to bends to get a smoother drive out, and then pop it back into D once I've cleared it.
It's all about how lazy you want to be and what you want the car to do.
Edited by wiliferus on Wednesday 16th July 21:56
Point is, its a little under powered so the box has to make the best of it.
bennyboysvuk said:
DonkeyApple said:
Quite right. I think I get more frustrated by these things than other drivers might too, hence my post. I do use the manual shift quite often, but I find on my 12 mile commute that I'll slip the box into manual mode on probably 5 occasions in maybe 20 minutes of driving...which probably suggests that I should have chosen a manual as the auto isn't really suitable for my needs. Oh well, live and learn.
You're overcomplicating this! You don't know how to drive with an auto. Give it some time and you will learn...Edited by Sump on Thursday 17th July 13:09
BL Fanboy said:
Nice car - I had a 2.6 CDX Omega and its not a bad autobox at all. The trouble is the Car is just too darn heavy for the engine, admittedly its a sight better than the 4 cylinder cars but it needs quite a bit more than 180bhp with the autobox to not feel a little leaden.
Point is, its a little under powered so the box has to make the best of it.
My previous cars were Omegas, a 2.5 then a 3.0. In both cases the autobox was excellent but only after I had the firmware upgraded. If the cr is as it left the factory I can guarantee its not nice, the upgrade changes the shift points and also introduces a modulated change which smooths out the shifts making it a very nice box indeed.Point is, its a little under powered so the box has to make the best of it.
Dodsy said:
My previous cars were Omegas, a 2.5 then a 3.0. In both cases the autobox was excellent but only after I had the firmware upgraded. If the cr is as it left the factory I can guarantee its not nice, the upgrade changes the shift points and also introduces a modulated change which smooths out the shifts making it a very nice box indeed.
Hmm, 2.5 and 3.0 litre you say? Wonder if the software on the box was changed for the later 2.6 and 3.2 litre cars.. wiliferus said:
The slush box in my 2.6 Omega needs to be controlled and driven. Stick it in D and just drive it wafts around and makes clumsy changes at inappropriate times.
If I use tactical use of the 'Sport' mode, it will hold the gear longer for sweeping bends or a series of corners. I even flick it into sport for bigger roundabouts so I don't get a mid junction change.
Often I'll use the stick to lock it into 2nd or 3rd on approaches to bends to get a smoother drive out, and then pop it back into D once I've cleared it.
It's all about how lazy you want to be and what you want the car to do.
If you go to all that effort then why not buy a manual in the first place?If I use tactical use of the 'Sport' mode, it will hold the gear longer for sweeping bends or a series of corners. I even flick it into sport for bigger roundabouts so I don't get a mid junction change.
Often I'll use the stick to lock it into 2nd or 3rd on approaches to bends to get a smoother drive out, and then pop it back into D once I've cleared it.
It's all about how lazy you want to be and what you want the car to do.
Edited by wiliferus on Wednesday 16th July 21:56
There is no comparison between putting some thought and a little bit of effort into getting an automatic to bend to your will in the few circumstances, usually predictable once you learn how to drive it properly, where the transmission brain can't deal with perfectly, mainly because it doesn't have a crystal ball, and all the effort needed in heavy traffic, clogged cities and long delays on motorways.
I used to be in the never have an auto camp. Mainly because of experience with limited ratios and slush boxes, no compression braking, points at the old Met SD1 with zero brakes after any distance at pace.
Converted by dual clutch, firstly the Volvo/Ford Power shift, then DSG and now PDK. Even grudgingly put up with a multispeed torque converter job that seems to achieve lock up in most gears. Not perfect but it's only used as a wafter and off road so it's Ok.
I used to be in the never have an auto camp. Mainly because of experience with limited ratios and slush boxes, no compression braking, points at the old Met SD1 with zero brakes after any distance at pace.
Converted by dual clutch, firstly the Volvo/Ford Power shift, then DSG and now PDK. Even grudgingly put up with a multispeed torque converter job that seems to achieve lock up in most gears. Not perfect but it's only used as a wafter and off road so it's Ok.
Dont't flame me, but I quite like the CVT in my Rav4 we use in the hills. My other cars are all manual and RWD, but for shuttling duties the cvt is great and suits the car and task in hand just fine. Very smooth, with paddles and pseudo gears for overtaking but rarely used, it's not a sports car! 8 speed XF box sounds excellent but is reserved for cars costing lot more than Rav4s.
FiF said:
Converted by dual clutch, firstly the Volvo/Ford Power shift, then DSG and now PDK.
The gear changes are far superior in the twin clutch though loads quicker and smoother and if you like using paddles you get a nice throttle blip on down changes, I still prefer the slower dark aged manual set up though as it just cant be bettered for feel, enjoyment and overall satisfaction for me personally.
I am very impressed by the 8 speed ZF box in my Q7.
It can lock the torque converter up in any gear I believe from about 1500 rpm so you can use all the diesel torque (4.2tdi) but one of the best features is the fact it is about the only auto box that can block change/miss a gear or more going up or down where as most have to go through each gear.
The worst has to be the dct box in the Fuso I drive at work as that is never in the right gear and takes so long to decide what gear it needs it often stops in the middle of junctions or even stalls!
It can lock the torque converter up in any gear I believe from about 1500 rpm so you can use all the diesel torque (4.2tdi) but one of the best features is the fact it is about the only auto box that can block change/miss a gear or more going up or down where as most have to go through each gear.
The worst has to be the dct box in the Fuso I drive at work as that is never in the right gear and takes so long to decide what gear it needs it often stops in the middle of junctions or even stalls!
St John Smythe said:
wiliferus said:
The slush box in my 2.6 Omega needs to be controlled and driven. Stick it in D and just drive it wafts around and makes clumsy changes at inappropriate times.
If I use tactical use of the 'Sport' mode, it will hold the gear longer for sweeping bends or a series of corners. I even flick it into sport for bigger roundabouts so I don't get a mid junction change.
Often I'll use the stick to lock it into 2nd or 3rd on approaches to bends to get a smoother drive out, and then pop it back into D once I've cleared it.
It's all about how lazy you want to be and what you want the car to do.
If you go to all that effort then why not buy a manual in the first place?If I use tactical use of the 'Sport' mode, it will hold the gear longer for sweeping bends or a series of corners. I even flick it into sport for bigger roundabouts so I don't get a mid junction change.
Often I'll use the stick to lock it into 2nd or 3rd on approaches to bends to get a smoother drive out, and then pop it back into D once I've cleared it.
It's all about how lazy you want to be and what you want the car to do.
Edited by wiliferus on Wednesday 16th July 21:56
jamieduff1981 said:
lord trumpton said:
we've recently bought an old gen X3 3.0d Auto.
Its the perfect family hack and the torquey diesel works well with the auto box. I couldn't have a TC auto box on a weekend car though - far too lethargic for a sporty type drive
This is a torque converter auto http://youtu.be/Ic3hmg4qb90 driven by PH round the Nurburgring for a recent article there's an ongoing thread about.Its the perfect family hack and the torquey diesel works well with the auto box. I couldn't have a TC auto box on a weekend car though - far too lethargic for a sporty type drive
I can't speak for anyone else but that gearbox is the furthest thing from lethargic and it's easily quicker than I could get through the T5 manual gearbox in my Cerbera. Despite being faster on paper, my Cerbera wouldn't see which way my wife's XF went, let alone the F-Type R. That's not the reason I'm keeping the Cerbera for the time being, but we all need to stop pretending manual cars are fast because nowadays because they just aren't. Certainly not when the clutch itself lasts under 30k when driving normally and costs £900 just for the parts. Powershifting and general mechanical abuse seem like a decidedly poor way to try to keep up with a modern auto in a powerful car. They can still be fun within the realms of our own little world when driving, but nobody is going to convince me they could hustle a comfortable, well equipped sports car round a challenging track like the Nurburgring quicker with a manual gearbox than they could with the ZF auto.
It's missing the tactility, I get that and somewhat subscribe to the idea myself, but the latest TC autos are anything but lethargic.
Apparently the ZF 'box in the BMW M135i is the one to have.
For the record - I'm not a "manual or nothing' man. Ive owned a fair few automated cars SMG2, DCT, DSG etc and they are fab. Id go so far as to say that Manual cars seem pretty pointless in the face of todays modernity on the cog swappers.
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