high performance automatics better for high performance cars?

[Kaido]

While the number of gears in a particular type of transmission are, as you correctly point out, largely irrelevant, the type of transmission absolutely is.

As moderator, you should already know this:

CVT-slushbox
DCT-slushbox
9-speed-slushbox
etc.

 

[Zenmervolt]

As moderator, you should already know this:

CVT-slushbox
DCT-slushbox
9-speed-slushbox
etc.

The term "slushbox" derives from the fluid coupling of a torque converter, specifically referring to the old-style torque converter automatics without a lockup clutch but generally applied to anything using a torque converter.

A DCT, by definition, cannot be a "slushbox."

ZV

 

[smackababy]

For discussion's sake. Automatic 5-speed, automatic 6-speed, automatic 9-speed, CVT, DCT, 1-gear, it's all the same to me: automatic, not manual

For argument's sake, having to put it in drive (or reverse) manually means, to me ofc, that it is, in fact, a manual transmission.

 

[npaladin-2000]

??

If there's no shifting at all, there can't be automatic shifting, which is what distinguishes an automatic transmission. Plus, without a torque converter the fixed gear Tesla transmission has a direct connection to the electric motor which means you get manual-transmission levels of engine braking as well.

If there's no clutch pedal it's not a "true" manual transmission. Just ask any member of the Clutch Pedal Crazies.

 

[Drako]

I'll stick with my manual 5 or 6, thank you .

If I was racing, I could consider the automatic.

 

[npaladin-2000]

The term "slushbox" derives from the fluid coupling of a torque converter, specifically referring to the old-style torque converter automatics without a lockup clutch but generally applied to anything using a torque converter.

A DCT, by definition, cannot be a "slushbox."

ZV

You're arguing with one of the aforementioned Clutch Pedal Crazies.

And if the "slush" truly comes from the torque converter, then a transmission with no torque converter shouldn't be a slushbox. There's a few automatics, particularly performance ones, that dump the torque converter, or minimize the use for it, in favor of a lock-up clutch. In some ways they "shift" faster than DCTs because of the planetary design, there's less of a disengagement step, if any. DCT still has to disconnect the drivetrain to switch to the new gear, for however brief a period. Planetaries work differently, and CVTs don't even shift at all, therefore no disconnect at all.

CVTs have consistently shown themselves to be the fastest 0-60 transmission versus other options, they have a lot of good qualities. Feel however, isn't one of them (they're laggy as all hell), because no one is bothering working on a performance version. Partially because few races allow them, they're worried that they're too efficient and would be destabilizing, meaning they'd put the other tranny manufacturers out of business.

If it sounds like I have sour grapes about that, it's because I do. I want to see a frigging performance-oriented non-rubbery hyper-efficient and fast CVT transmission.

 

[kitatech]

re: npaladin-2000

Good points...one might say that shifting is one of the skill sets being tested in a race to be bested by the winner...it's not just about speed and steering...

 

[The Boston Dangler]

If there's no clutch pedal it's not a "true" manual transmission. Just ask any member of the Clutch Pedal Crazies.

of course it is. as long as you're manually selecting a ratio, it's a manual transmission. h-gate, up/down paddles/stick/pedal, double clutching with a pre-selector slider on the wheel...it makes no difference how the driver inputs his command, only that his command is obeyed.

 

[The Boston Dangler]

If it sounds like I have sour grapes about that, it's because I do. I want to see a frigging performance-oriented non-rubbery hyper-efficient and fast CVT transmission.

1993 Williams FW15C CVT
http://www.youtube.com/watch?v=x3UpBKXMRto

insta-banned, although it didn't help that all other driver aides and automation was banned for 94. if the concept was developed it would have made every track in the world obsolete and killed drivers left and right, as the cars would constantly produce max horsepower and max downforce.

 

[_Rick_]

of course it is. as long as you're manually selecting a ratio, it's a manual transmission. h-gate, up/down paddles/stick/pedal, double clutching with a pre-selector slider on the wheel...it makes no difference how the driver inputs his command, only that his command is obeyed.

Well, I suppose there's a gray area.
There is fully manual, where every gear change is mechanically directly effected by manual interaction. You'll either have an H-pattern or a ruddy big sequential lever, and usually a clutch pedal or handle, on the sequentials for downshifts only.
There's the robo-manuals, where a basic manual gear box is present, but the actual user interaction is transmitted as an electrical impulse to a computer, which uses actuators to actually change the gear. This includes the double clutch boxes, but also the single clutch robo boxes and sequential boxes with paddle operation. These boxes have partial to full clutch automation.
And then there is the full automatics, where user interaction is limited to the minimumm and user input only allowed for corner cases. (CVT and hydraulic torque converters)

Pure electric cars are usually fixies, as this is most efficient at low to medium speeds, while hybrids with the electric motor connected to the axles usually get a clutch so that at high speed the axle freewheels along.

Oh, and the next big thing will probably be the nav-enhanced auto which works really well in the latest Rolls Royce, according to the review. I suspect it may well be good enough for sporty driving as well, because the car will know how you're driving, what the upcoming corner looks like, and what gear best suits the change of direction.

 

[Fayd]

Give me a 2500lb 2-seater with 400hp and 5 on the floor and I'm in heaven.

http://en.wikipedia.org/wiki/Ariel_Atom

1200 lbs under, 100 hp over, and an extra gear as an added bonus

 

[MagickMan]

I thought you already had one of those. >_>

Well, I suppose the 12C is a bit heavier, but it gets 200+ more HP and a 7 speed IIRC.

The 12C is great, but I've driven cars that are more fun.

 

[MagickMan]

http://en.wikipedia.org/wiki/Ariel_Atom

1200 lbs under, 100 hp over, and an extra gear as an added bonus

We're building a TT small-block Cobra; 650-750bhp, ~2500lbs, w/ Tremec 6-spd manual. That'll do.

 

[Zenmervolt]

There's a few automatics, particularly performance ones, that dump the torque converter, or minimize the use for it, in favor of a lock-up clutch. In some ways they "shift" faster than DCTs because of the planetary design, there's less of a disengagement step, if any. DCT still has to disconnect the drivetrain to switch to the new gear, for however brief a period. Planetaries work differently, and CVTs don't even shift at all, therefore no disconnect at all.

Planetary gear transmissions still have a brief period of disengagement between gears. They shift by engaging and disengaging small multi-plate clutches ("clutchpacks") to freeze or free specific portions of the planetary set (i.e. locking the ring gear in place and using the planet carrier as output, locking the planet carrier and using the ring gear as output, locking the planet gears to give a 1:1 ratio, etc.). To shift from one gear set to another, everything is briefly uncoupled before the next gear is engaged.

There's the same "disengage prior gear, engage subsequent gear" process in a planetary automatic as there is in a DCT. In fact, a mal-adjusted planetary automatic can end up binding, or being "in two gears at once" if the "disengage/re-engage" process is not occurring properly. This was mostly an issue for very old planetary automatics (pre-electronic controls, and especially very early Hydramatic units).

Also, I know of no planetary automatic that completely dispenses with the torque converter. While almost all modern torque converter automatics have a lockup clutch for the top gear (it was common even in the late 1980s for a torque converter automatic to have lockup in 4th gear), and while many are now engaging the lockup clutch in lower gears, the fact remains that the lockup clutch only remains engaged at either zero or very slight acceleration; firm application of the accelerator will always disengage the lockup clutch, even before the transmission downshifts. Increased use of the lockup clutch is driven largely by fuel economy concerns, not by performance concerns since the torque converter's slippage actually provides torque multiplication and is beneficial to acceleration even if it can feel odd.

You're right that CVTs have no power interruptions when "shifting" though. However, historically, CVTs have had problems with high-torque applications. While it's true that CVTs were tested in F1, even F1 cars produce less than 300 ft-lbs of torque. They gain their high horsepower from being able to rev very high. Nissan has done great work with their CVTs, but they're still not offered on anything with over about 265 fl-lbs of torque.

DCTs, on the other hand, are as robust as traditional manuals transmissions and they have the same ultra-fast shifting times as are theoretically possible with planetary setups.

ZV

 

[npaladin-2000]

Well, I suppose there's a gray area.
There is fully manual, where every gear change is mechanically directly effected by manual interaction. You'll either have an H-pattern or a ruddy big sequential lever, and usually a clutch pedal or handle, on the sequentials for downshifts only.
There's the robo-manuals, where a basic manual gear box is present, but the actual user interaction is transmitted as an electrical impulse to a computer, which uses actuators to actually change the gear. This includes the double clutch boxes, but also the single clutch robo boxes and sequential boxes with paddle operation. These boxes have partial to full clutch automation.
And then there is the full automatics, where user interaction is limited to the minimumm and user input only allowed for corner cases. (CVT and hydraulic torque converters)

Pure electric cars are usually fixies, as this is most efficient at low to medium speeds, while hybrids with the electric motor connected to the axles usually get a clutch so that at high speed the axle freewheels along.

Oh, and the next big thing will probably be the nav-enhanced auto which works really well in the latest Rolls Royce, according to the review. I suspect it may well be good enough for sporty driving as well, because the car will know how you're driving, what the upcoming corner looks like, and what gear best suits the change of direction.

To get back to topic here, where would you put the performance automatics with full paddle/bumpshift gear selection and a near 100% "true manual" mode where it holds to redline and only shifts when the driver tells it? Sounds like that would straddle your robo and full categories, since user interaction is most definitely NOT limited, merely optional.

And some of the "enthusiasts" out there aren't going to consider a "robo" a manual under any circumstance. To them there are two transmission types: ones with clutch pedals (called "manuals") and everything else is an "automatic."

 

[MagickMan]

Yep. Either it has 3 pedals or it doesn't.

 

[Fenixgoon]

for absolute track performance, yes.

i still like the "feel" of shifting up gears, whether i'm on my bike or in my car.

 

[Pacfanweb]

For a sports car, I wouldn't mind a manual, although I don't think an automatic would be less fun. You can still manually shift it.

For my Jeep CJ, it has always had a manual. Old Jeeps should be sticks, because....well, just because.


For a daily driver that isn't some type of sports car? Automatic all the way. There's not much more of a downer to the driving experience than sitting in bumper-to-bumper traffic in a stick car.

 

[The Boston Dangler]

As explained in a response to another poster earlier, what you're experiencing is not a true mechanical "lock out" but rather simply the normal functioning of the blocker rings (or "baulk rings") for each gear's synchronizer. A true "lock out" is something in the linkage. I guarantee that if you applied sufficient force to the gear lever, you would be able to override the baulk rings and engage those lower gears.

so something can be damaged or destroyed with deliberate effort or severe abuse? i can't say that catches me by surprise.

 

[cbrsurfr]

It's only a matter of time before the manual fades into obsolescence. Fewer and fewer cars even offer it anymore (911 Turbo and GT3 are the latest victims). But but I'm going to vote with my wallet, you say. Good luck with that once its no longer economically viable to produce/test/certify a manual. You'll be stuck with 20 year old relics after everyone else in the world has moved on.

I for one welcome our DCT overlords. I refuse to buy a manual and I refuse to buy a traditional "auto". My last 2 cars were DCT's and I love them. Paddle, Auto, Sport, Tiptronic, I have a "mode" for however I feel at the time.

 

[The Boston Dangler]

It's only a matter of time before the manual fades into obsolescence. Fewer and fewer cars even offer it anymore (911 Turbo and GT3 are the latest victims). But but I'm going to vote with my wallet, you say. Good luck with that once its no longer economically viable to produce/test/certify a manual. You'll be stuck with 20 year old relics after everyone else in the world has moved on.

I for one welcome our DCT overlords. I refuse to buy a manual and I refuse to buy a traditional "auto". My last 2 cars were DCT's and I love them. Paddle, Auto, Sport, Tiptronic, I have a "mode" for however I feel at the time.

people that matter, the ones actually buying porsches, ferraris and other legit high-end hardware, have been voting with their wallets for a decade. people spending 6 figures on cars do not buy sticks.

 

[_Rick_]

To get back to topic here, where would you put the performance automatics with full paddle/bumpshift gear selection and a near 100% "true manual" mode where it holds to redline and only shifts when the driver tells it? Sounds like that would straddle your robo and full categories, since user interaction is most definitely NOT limited, merely optional.

And some of the "enthusiasts" out there aren't going to consider a "robo" a manual under any circumstance. To them there are two transmission types: ones with clutch pedals (called "manuals") and everything else is an "automatic."

When going for laptimes, I definitely want paddles. Taking a hand off the wheel while threading on the brakes/throttle through a chicane is just scary.
If I'm just driving at 80-90% grip levels for fun on public roads: a direct coupling is good enough, a stick will be very nice too. I wouldn't want more than 400 HP and 300Nm of torque from the engine, as beyond that the clutch pedal often gets very heavy, which doesn't make for fun driving. Fun driving requires a car that is agile and communicative.

Any car with more than 3 doors? If economy is okay, any smooth auto is good enough, even a CVT should do.

Edit: downside of double clutches? All the extra weight. Otherwise they're pretty awesome.

 

[NutBucket]

Forget the weight. I want to know how long those clutches last and what it will cost me to replace them! I highly doubt they will last over 100k.

 

[GoodRevrnd]

I would expect the clutch plates themselves would actually last longer since they're always making perfect shifts. As for the rest of the complicated components that factor into their operation, I suppose that's another story...

 

[cbrsurfr]

Forget the weight. I want to know how long those clutches last and what it will cost me to replace them! I highly doubt they will last over 100k.

There's plenty of VW DSG's over 100K. I've even seen some TDI's with over 200K.