The Automatic Gearbox And Its Failings

The Automatic Gearbox And Its Failings

Author
Discussion

Clivey

5,108 posts

203 months

Saturday 26th July 2014
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DonkeyApple said:
That's a humongous amount of rubber. I think this is also why some people at that the manual box gives more control.
One of the reasons. wink Occasionally, I wish for a manual when off-road in the Discovery.

DonkeyApple said:
To get cars with this much rubber to break away and be a laugh while still being safe you have to bugger about with the clutch.
As I see it, having a manually-operated, analogue clutch is the main thing that gives you more control over a manual 'box than you get with an auto (where you're lucky if you can vary the shift speed etc via pre-programmed modes or in increments).

An auto (paddleshift) box is like hunting with a rifle; pull the trigger and "boom". A manual however is like getting up close and personal with a knife.

DonkeyApple said:
With that much rubber the speed you'd need to be travelling to break away via the throttle and the skill to catch and hold something that is going to be snapping so suddenly it's just not sensible.
yes For me, the first time I slid mine was on one of those dual carriageway slip roads that goes around 3/4 of a circle. It was sudden but at least the balance is there with the E46 chassis. From what's been said here, it seems as if more and more understeer is being dialled-in to the setup of the newer cars.

JagXJR

1,261 posts

128 months

Saturday 26th July 2014
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CR6ZZ said:
I'll admit to being one of the minority. I just enjoy changing gear myself - ......................

One thing an auto falls down (correct me if I'm wrong) on is that, if by some chance the battery goes flat, you can't give it a push to get it going.
The big thing that is continually getting overlooked is you CAN in an auto! Jaguar even made it easier with the J box (a superb design so you know by feel if you are in manual or automatic mode).

So the driving gods can still control the car manually.

Perhaps having driven millions of miles in urban traffic I have gotten fed up of doing so, but I still manually change the gears myself sometimes, just prefer the car to do it itself as it does such a good job of doing so.

As for the flat battery point, perhaps the failing is not the auto but the dufus leaving their lights on and flattening the battery? Or not maintaining the car properly and changing the battery when it is failing? Or how about keeping a pair of jump leads in the boot? This is silly scenario and not a failing of an automatic gearbox.

I put it to the board that a good automatic does not have a failing, except perhaps the operator?


JagXJR

1,261 posts

128 months

Saturday 26th July 2014
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ORD said:
McSatan said:
E65Ross said:
McSatan said:
Wheelspins. I couldn't spin the wheels on my Mum's Daf 44 Variomatic. But I could on her Vauxhaull Viva. Cars with manual clutches are better, there's an end of it. smile
So you're saying that the manual is better because you couldn't do something on an old variomatic gearbox? OK....
Yes. I'm glad you agree with me.
The rear wheels on my car will spin and spin with an appropriately ham-footed application of throttle. Not sure what a manual clutch has got to do with that. It's more about the power/traction relationship and how intrusive the settings for the electronic driver aids.
I can assure you the XJR is more than capable of spinning the wheels, that's why it has traction control rolleyes

E65Ross

34,947 posts

211 months

Saturday 26th July 2014
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If you reach understeer on the public road in a modern 3er then you'll be going too quick imo. Even reaching understeer in my old 7er takes some silly speeds.

JagXJR

1,261 posts

128 months

Saturday 26th July 2014
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FiF said:
For me the one thing that autos are bad at is dealing with the typical situation when entering such as a busy roundabout. It's the "prepared to stop looking to go" situation, especially if it's in D, less so in sports but can still be an issue.

It's the slowing, slowing, getting really slow now, go go go scenario.

The sort of thing where in a true manual you would either be in first or second ready and able to go without any hesitation while it has a think. The gear you are in could of course be the wrong one and the engine could bog or whatever, but that's just the case of any vehicle in learning the envelope of what it can do and knowing wwhether for thatvehicle first or second Iis the best option.

So far the auto I have so far owned that dealt with this scenario the best was a Volvo power shift DCT. In 'manual' mode get it into second and it would not change to first until you physically stopped. Even if the wheels were only just rolling it would hold second and still give a reasonable getaway.
Non of my autos do this, perhaps those complaining have bought the wrong car? Or maybe they are broken?

Clivey

5,108 posts

203 months

Saturday 26th July 2014
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E65Ross said:
If you reach understeer on the public road in a modern 3er then you'll be going too quick imo.
Yeah, yeah... wink

Welshbeef

49,633 posts

197 months

Saturday 26th July 2014
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E65Ross said:
If you reach understeer on the public road in a modern 3er then you'll be going too quick imo. Even reaching understeer in my old 7er takes some silly speeds.
Very true - I could go round very right corners in the 3er at a good 60mph.

Some slip roads I'd push 80-95 and even then it gripped so well the TC light would flicker at the upper end of that range zero unsteer god knows what speeds you must be doing to achieve this

JagXJR

1,261 posts

128 months

Saturday 26th July 2014
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E65Ross said:
I can tell you that I was bloody glad I had an auto on the way into work Tuesday.......

you could start another thread "manual gearbox and its failings" and complain about how you have to use your left arm and leg to change gear when you could have a computer do it for you; how it's slower, less efficient; or how if you're pootling along in 4th or 5th gear (or higher) and suddenly need to overtake someone and nail the throttle you find yourself in the wrong gear and the time to change gear and floor it is too slow, when an automatic or DCT box will downshift 2-3 gears in the blink of an eye and bam you're gone.......I had that exact scenario yesterday I was on a dual carriageway 70mph limit overtaking someone before it went into 1 lane and they suddenly decided to speed up so I had to floor it, at the time I was in 6th gear but the car quickly shifted into 3rd and got a shift on and I got round them, in a manual car I'd probably have been caught out and got stuck behind them.
exactly this.

My manual gearbox car failed me when the clutch went recently. Could not put in gear with the engine on, Had to be towed to the garage.

I have the manual car for county drives and the auto for commuting. If I only had one car it would be a (decent) auto. It does exactly what I tell it to do, without fail. Perhaps I am happier to use technology than some.

An auto is always in gear, when you are changing gear in a manual it is not. So for a short time you are not in control with a manual.

I get the argue about feel, however in a mundane car even the best gearbox it will still feel mundane to drive. I never had that feeling in the Jaguars. The Subaru however can feel boring to drive.

I still think based on my experience it is the car that feels boring, not the transmission. Can a manual gearbox really make a silk purse out of a pigs ear? I think not.

JagXJR

1,261 posts

128 months

Saturday 26th July 2014
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bennyboysvuk said:
You may be right. I wrote a list earlier with 23 items on it that annoy me about the car. They're nearly all things that probably wouldn't frustrate anyone that didn't have an interest in cars though. I really feel that a Mondeo for half the price would do just as good a job as the 330 and possibly better it in the handling department.
So you are in agreement it is the car you bought that you don't like rather than the gearbox?

Nothing wrong with Mondeos, after all the X-type Jaguar is based on its platform laugh

bennyboysvuk

Original Poster:

3,491 posts

247 months

Sunday 27th July 2014
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E65Ross said:
If you reach understeer on the public road in a modern 3er then you'll be going too quick imo. Even reaching understeer in my old 7er takes some silly speeds.
It happens at anything over about 35mph, right upto NSL and above.

E65Ross

34,947 posts

211 months

Sunday 27th July 2014
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bennyboysvuk said:
E65Ross said:
If you reach understeer on the public road in a modern 3er then you'll be going too quick imo. Even reaching understeer in my old 7er takes some silly speeds.
It happens at anything over about 35mph, right upto NSL and above.
Well if you're going around a hairpin, maybe.

bennyboysvuk

Original Poster:

3,491 posts

247 months

Sunday 27th July 2014
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JagXJR said:
I can assure you the XJR is more than capable of spinning the wheels, that's why it has traction control rolleyes
If that's why the Jag has it I've no idea why the 330 does. wink


GroundEffect

13,819 posts

155 months

Sunday 27th July 2014
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DonkeyApple said:
liner33 said:
As I mentioned earlier many cars use the throttle pedal as an input to the ecu with the latter making the decision on how much to actually open the engines throttle. I know my 370z will only open the throttle 70% maximum in first gear , and about 85-90% in second , to help support traction , that may well be the case with yours

Luckily this can be mapped out smile
It's also about torque management, arguably more so than traction which may well be a bit of marketing spin. The lowest/smallest gears are obviously the weakest.
Lowest gears are the largest. The problem is the torque multiplication...you can get 10000Nm in first gear on the output shaft.

E65Ross

34,947 posts

211 months

Sunday 27th July 2014
quotequote all
bennyboysvuk said:
JagXJR said:
I can assure you the XJR is more than capable of spinning the wheels, that's why it has traction control rolleyes
If that's why the Jag has it I've no idea why the 330 does. wink
I reckon there's something amiss, if I could get the wheels to spin on an E46 330i with an automatic gearbox, no reason the more powerful and similarly-tyred E90 wouldn't.

Either way, this thread has gone way, way off topic. Basically, you've tried slating an automatic gearbox for somewhat daft reasons and one could very easily write a similar thread about manuals (as per my somewhat sarcastic post a while ago).


bennyboysvuk

Original Poster:

3,491 posts

247 months

Sunday 27th July 2014
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E65Ross said:
Well if you're going around a hairpin, maybe.
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.

DonkeyApple

54,934 posts

168 months

Sunday 27th July 2014
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GroundEffect said:
Lowest gears are the largest. The problem is the torque multiplication...you can get 10000Nm in first gear on the output shaft.
Thanks.

jsp56

161 posts

116 months

Sunday 27th July 2014
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Would you mind my asking if there are any really quite small cars with good automatic gear boxes in them? Something about the size of a KA?

Thanks!

ORD

18,086 posts

126 months

Monday 28th July 2014
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Classic PH - two people who own or have recently driven a car say it understeers at perfectly safe speeds; others come on and say they must have been driving really fast! As the OP says, a current model 3 with the basic suspension will understeer at well below NSL on moderate bends (i.e. the kind of bends for which none of us would lift off, let alone brake).

We're not talking leave-the-road-trough-a-hedge understeer. It just fails slightly to hold its line as the fronts run wide by a foot or two. It's very noticeable if you are used to cars that corner more neutrally. Old 3s were a lot more neutral, in my experience.

va1o

16,029 posts

206 months

Monday 28th July 2014
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jsp56 said:
Would you mind my asking if there are any really quite small cars with good automatic gear boxes in them? Something about the size of a KA?

Thanks!
Not really, most cars that size are better suite to a manual. Best bet would be stepping up to something like a Polo DSG or Fiesta Powershift

Ozzie Osmond

21,189 posts

245 months

Monday 28th July 2014
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There really are some very, very good autos out there. It's not 1975 any more!