The Automatic Gearbox And Its Failings
Discussion
redtwin said:
That's because the RR has a conventional auto with a torque converter not an automated manual with a clutch controlled by an indecisive ECU.
A world of difference between the two.
That's going back to basics a bit.. Cars still have four wheels yet they're massively different from decades ago. A world of difference between the two.
The modern auto with a torque converter is way faster shifting, can block shift 3 gears and can hold on to gears intelligently. Half of this new functionality is down to very intelligent software, the other half is better mechanical design.
To solely blame a not so good auto design on the ECU isn't quite correct since all types of autos rely on incredible computing power. A bad system could be down to mechanical design as much as the ECU, or the calibration of how the two interface.
Welshbeef said:
Turn TC off
Like I hadn't thought of that. 
I tried it with both DTC on and off.
When off it actually didn't spin at all initially on decent soaking wet tarmac, but then the tarmac changed to that glossy, smooth stuff and it spun up as it went past 5k rpm.
The auto means that it's just uber-smooth the way that it goes from a standstill to maximum acceleration and therefore doesn't really trouble the traction very much at all...and that's in the wet!
bennyboysvuk said:
There and roundabout exits and s bends and dual carriageway slips, most corners really.
It should feel so much more rewarding than it does, with that feeling of all four tyres being hooked up and depending on whether you close or open the throttle the chassis and line the car takes changes. Instead I could apply full lock at 45 mph on a roundabout and steer the same course with the fronts scrubbing wide. Lifting off would stop the understeer, but the front shouldn't be that unbalanced in the first place. Of course changing all the bushes, suspension arms etc would help massively but this is so different from Sports of old. They've lost their verve.
I'm not sure if you're speaking hypothetically, but I'd be amazed if it could steer accurately on full lock at 10MPH never mind 45MPH.It should feel so much more rewarding than it does, with that feeling of all four tyres being hooked up and depending on whether you close or open the throttle the chassis and line the car takes changes. Instead I could apply full lock at 45 mph on a roundabout and steer the same course with the fronts scrubbing wide. Lifting off would stop the understeer, but the front shouldn't be that unbalanced in the first place. Of course changing all the bushes, suspension arms etc would help massively but this is so different from Sports of old. They've lost their verve.
ORD said:
Sheepshanks said:
I'm not sure if you're speaking hypothetically, but I'd be amazed if it could steer accurately on full lock at 10MPH never mind 45MPH.
I read it to mean "on a full turn of the wheel", but I might be wrong!Sheepshanks said:
Well, it doesn't really matter - if you apply a lot of (rather than full) lock at some speed then, hey, guess what, it'll understeer. If it didn't, you'd get dramatic oversteer. If it gripped at both ends the centrifugal force would probably put you into the passenger seat!
Dramatic oversteer is what he was after - he was trying to get the back end to let go so that he could slide it a bit.bennyboysvuk said:
Like I hadn't thought of that.
I tried it with both DTC on and off.
When off it actually didn't spin at all initially on decent soaking wet tarmac, but then the tarmac changed to that glossy, smooth stuff and it spun up as it went past 5k rpm.
The auto means that it's just uber-smooth the way that it goes from a standstill to maximum acceleration and therefore doesn't really trouble the traction very much at all...and that's in the wet!
Is that pressing the DTC button or holding it for 5 seconds?I tried it with both DTC on and off.
When off it actually didn't spin at all initially on decent soaking wet tarmac, but then the tarmac changed to that glossy, smooth stuff and it spun up as it went past 5k rpm.
The auto means that it's just uber-smooth the way that it goes from a standstill to maximum acceleration and therefore doesn't really trouble the traction very much at all...and that's in the wet!
The latter turns everything off the former does something else. I think just pressing it keeps DSC on but allows a little bit of traction slip. Holding it down for 5 seconds should turn the lot off.
DonkeyApple said:
bennyboysvuk said:
Like I hadn't thought of that.
I tried it with both DTC on and off.
When off it actually didn't spin at all initially on decent soaking wet tarmac, but then the tarmac changed to that glossy, smooth stuff and it spun up as it went past 5k rpm.
The auto means that it's just uber-smooth the way that it goes from a standstill to maximum acceleration and therefore doesn't really trouble the traction very much at all...and that's in the wet!
Is that pressing the DTC button or holding it for 5 seconds?I tried it with both DTC on and off.
When off it actually didn't spin at all initially on decent soaking wet tarmac, but then the tarmac changed to that glossy, smooth stuff and it spun up as it went past 5k rpm.
The auto means that it's just uber-smooth the way that it goes from a standstill to maximum acceleration and therefore doesn't really trouble the traction very much at all...and that's in the wet!
The latter turns everything off the former does something else. I think just pressing it keeps DSC on but allows a little bit of traction slip. Holding it down for 5 seconds should turn the lot off.
Sheepshanks said:
Well, it doesn't really matter - if you apply a lot of (rather than full) lock at some speed then, hey, guess what, it'll understeer. If it didn't, you'd get dramatic oversteer. If it gripped at both ends the centrifugal force would probably put you into the passenger seat!
Once it starts understeering it is possible to simultaneously apply more throttle and more lock until it gets to full lock, yet steering the same course. It's as easy to do in this car as many, many FWD cars I've owned over the years, but it's a terribly boring trait in a car. What I'm trying to highlight is how much the car understeers. It's far, far less neutral than pre-2005 3 series BMWs, to a ridiculous degree. There's no balancing the front and back end through a corner on the throttle and feeling the suspension load and unload front to rear as the weight transfer changes, there is only managing understeer. It will only steer even the slightest bit neutrally when trail braking from corner entry to exit, which is the opposite of all driving recommendations and feels dreadful. I know the 3 series used to have a reputation as being a little loose at the rear in the wet, but IMO BMW have gone way too far in trying to make it unbelievably safe for the average driver. I wouldn't be surprised if all crashes in 2006+ 3 series were all front end smashes.Congrats if you got this far, I hadn't realised how much I'd babbled on.
ORD said:
E65Ross said:
Are you for real? The DCT box in the new M6 is every bit as smooth and good as an auto as the old 5 or 6 speed traditional autos. Only faster and more responsive. And more efficient. And they give you more control.
I've not driven the M6 so cant comment on that. I find the ZF's attempts to mimic a dual clutch box just make it neither one thing nor the other and a bit irritating to drive (except mated to a diesel engine, where it gets the most of the smoker, but that is mostly because of the number of ratios).jamieduff1981 said:
ORD said:
E65Ross said:
Are you for real? The DCT box in the new M6 is every bit as smooth and good as an auto as the old 5 or 6 speed traditional autos. Only faster and more responsive. And more efficient. And they give you more control.
I've not driven the M6 so cant comment on that. I find the ZF's attempts to mimic a dual clutch box just make it neither one thing nor the other and a bit irritating to drive (except mated to a diesel engine, where it gets the most of the smoker, but that is mostly because of the number of ratios).It is a perfectly adequate 'box (and suits the diesels better than the petrol engines) but it is not better than a decent auto from years ago. Like a lot of things found in BMWs and/or VWs, it gets unjustifiably gushing reports from the motoring press.
bennyboysvuk said:
Sheepshanks said:
Well, it doesn't really matter - if you apply a lot of (rather than full) lock at some speed then, hey, guess what, it'll understeer. If it didn't, you'd get dramatic oversteer. If it gripped at both ends the centrifugal force would probably put you into the passenger seat!
Once it starts understeering it is possible to simultaneously apply more throttle and more lock until it gets to full lock, yet steering the same course. It's as easy to do in this car as many, many FWD cars I've owned over the years, but it's a terribly boring trait in a car. What I'm trying to highlight is how much the car understeers. It's far, far less neutral than pre-2005 3 series BMWs, to a ridiculous degree. There's no balancing the front and back end through a corner on the throttle and feeling the suspension load and unload front to rear as the weight transfer changes, there is only managing understeer. It will only steer even the slightest bit neutrally when trail braking from corner entry to exit, which is the opposite of all driving recommendations and feels dreadful. I know the 3 series used to have a reputation as being a little loose at the rear in the wet, but IMO BMW have gone way too far in trying to make it unbelievably safe for the average driver. I wouldn't be surprised if all crashes in 2006+ 3 series were all front end smashes.Congrats if you got this far, I hadn't realised how much I'd babbled on.
ORD said:
I was pretty amazed at the lack of turn in on the F30 that I drove recently. It has made me really question everything that Autocar says given that they rate that car as "sublime". It handles like an Audi.
Could it be that the DSC is trying to straighten the car up all the time? I've seen reports that F10's are eating rear pads as it intervenes even in fairly normal driving.ORD said:
jamieduff1981 said:
ORD said:
E65Ross said:
Are you for real? The DCT box in the new M6 is every bit as smooth and good as an auto as the old 5 or 6 speed traditional autos. Only faster and more responsive. And more efficient. And they give you more control.
I've not driven the M6 so cant comment on that. I find the ZF's attempts to mimic a dual clutch box just make it neither one thing nor the other and a bit irritating to drive (except mated to a diesel engine, where it gets the most of the smoker, but that is mostly because of the number of ratios).It is a perfectly adequate 'box (and suits the diesels better than the petrol engines) but it is not better than a decent auto from years ago. Like a lot of things found in BMWs and/or VWs, it gets unjustifiably gushing reports from the motoring press.
jamieduff1981 said:
As mentioned numerous times in this thread and others, BMW haven't quite got the hang of this ZF gearbox lark and absolutely should not be used to judge the capabilities of the gearbox. JLR are far superior at programming it.
Are you talking about the new 8 speed box? If so, you're talking utter tripe 
Read the M135i reviews etc?
E65Ross said:
jamieduff1981 said:
As mentioned numerous times in this thread and others, BMW haven't quite got the hang of this ZF gearbox lark and absolutely should not be used to judge the capabilities of the gearbox. JLR are far superior at programming it.
Are you talking about the new 8 speed box? If so, you're talking utter tripe Read the M135i reviews etc?
I'm defending the gearbox. I think it's brilliant. I just don't think that odd-ball low volume BMW engine/gearbox combinations like the NA 3.0 petrol should be used as a benchmark of what can be done with that gearbox.
Specifically I'm referring to ORD claiming it's not any different from the sorts of old 4 and 5 speed autos from decades ago, based upon test driving a few BMWs.
Sheepshanks said:
Could it be that the DSC is trying to straighten the car up all the time? I've seen reports that F10's are eating rear pads as it intervenes even in fairly normal driving.
Perhaps in the faster corners, but not at sedate speeds, surely? Nowhere near the limits of grip.Gassing Station | General Gassing | Top of Page | What's New | My Stuff