CVT or Sequential transmission?

bolido2000

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Dec 3, 2001
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Which is going to be the transmission that will take over in the future? I'm pretty sure manual and automatics will eventually go away.
 

GTaudiophile

Lifer
Oct 24, 2000
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CVT is a new type of automatic transmission as far as I know. SMG is an evolution of the manual transmission. So, I have to go with SMG. Besides, do F1 drivers use CVT? No.
 

bolido2000

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Dec 3, 2001
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Originally posted by: TheEvil1
i dont know what either of thoes are.

i like standard its the only way to go

CVT = Continuously variable transmission. Infinite gear rations. The engine can be kept at its peak power when you accelerate. In other words, when you floor it the tach needle gets stuck in 5600RPM (or whatever the peak power is)

Sequential = Basically a manual with an electronically controlled clutch. No stupid torque converter. Best compromise IMO.

 

atom

Diamond Member
Oct 18, 1999
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CVT. SMG may make shifting easier, but most people are lazy as hell and CVT is still easier to drive.
 

KingNothing

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Apr 6, 2002
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CVTs are cool but they need to figure out how to make them withstand massive amounts of torque.

Assuming that doesn't happen, sequential (I assume you're talking about clutchless manuals ala BMW's SMG II) are the wave of the future.

Quick rundown:

CVT: Has no gears, adjusts the gear ratio by means of a belt (or chain, in Audi's case) and pulleys. All the efficiency of a manual and can accelerate a bit faster due to the fact that under hard acceleration it brings the RPMs to the power peak and leaves them there while it adjusts the gear ratios for acceleration.

Sequential:Clutchless manual means all the parts of a manual transmission - clutch pedal + hydraulics to operate clutch plates. BMW's SMG II can execute shifts in like 15 milliseconds, much faster than any human could. Also can do seamless downshifts and has an auto mode for when you don't want to hit the paddles to shift yourself.
 

bolido2000

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Dec 3, 2001
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Originally posted by: atom
CVT. SMG may make shifting easier, but most people are lazy as hell and CVT is still easier to drive.

Most SMG can shift automatically. Dunno what Toyota was thinking with the MR-2's SMG.
 

KingNothing

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Apr 6, 2002
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Originally posted by: bolido2000
Originally posted by: atom
CVT. SMG may make shifting easier, but most people are lazy as hell and CVT is still easier to drive.

Most SMG can shift automatically. Dunno what Toyota was thinking with the MR-2's SMG.

The MR2 costs a lot less than the BMW M3. Guess you have to cut corners somewhere. Was kind of stupid though.
 

bolido2000

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Dec 3, 2001
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Originally posted by: KingNothing
CVTs are cool but they need to figure out how to make them withstand massive amounts of torque.

Assuming that doesn't happen, sequential (I assume you're talking about clutchless manuals ala BMW's SMG II) are the wave of the future.

Quick rundown:

CVT: Has no gears, adjusts the gear ratio by means of a belt (or chain, in Audi's case) and pulleys. All the efficiency of a manual and can accelerate a bit faster due to the fact that under hard acceleration it brings the RPMs to the power peak and leaves them there while it adjusts the gear ratios for acceleration.

Sequential:Clutchless manual means all the parts of a manual transmission - clutch pedal + hydraulics to operate clutch plates. BMW's SMG II can execute shifts in like 15 milliseconds, much faster than any human could. Also can do seamless downshifts and has an auto mode for when you don't want to hit the paddles to shift yourself.


There are already CVT that can withstand lots of torque in Japan. Nissan Gloria (or Cima) in Japan.

Sequential still operates with a clutch. The difference is that the driver doesn't control it. Seamless downshift is just revv matching which any driver can do, although it would be slower than a computer of course.
 

KingNothing

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Apr 6, 2002
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Originally posted by: bolido2000
Originally posted by: KingNothing
CVTs are cool but they need to figure out how to make them withstand massive amounts of torque.

Assuming that doesn't happen, sequential (I assume you're talking about clutchless manuals ala BMW's SMG II) are the wave of the future.

Quick rundown:

CVT: Has no gears, adjusts the gear ratio by means of a belt (or chain, in Audi's case) and pulleys. All the efficiency of a manual and can accelerate a bit faster due to the fact that under hard acceleration it brings the RPMs to the power peak and leaves them there while it adjusts the gear ratios for acceleration.

Sequential:Clutchless manual means all the parts of a manual transmission - clutch pedal + hydraulics to operate clutch plates. BMW's SMG II can execute shifts in like 15 milliseconds, much faster than any human could. Also can do seamless downshifts and has an auto mode for when you don't want to hit the paddles to shift yourself.


There are already CVT that can withstand lots of torque in Japan. Nissan Gloria (or Cima) in Japan.

Sequential still operates with a clutch. The difference is that the driver doesn't control it. Seamless downshift is just revv matching which any driver can do, although it would be slower than a computer of course.

I never said sequential didn't have a clutch, only no clutch pedal. Sequentials can do a seamless downshift (by rev matching, yes) every time, and more perfectly than 98% of the drivers out there (myself included).

Link to the Gloria's CVT specs?
 

vi edit

Elite Member
Super Moderator
Oct 28, 1999
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CVT because good ones are superior to current gen automatics and even high dollar SMG shifters in nearly every way (performance wise)

 

bolido2000

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Dec 3, 2001
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Originally posted by: KingNothing
Originally posted by: bolido2000
Originally posted by: KingNothing
CVTs are cool but they need to figure out how to make them withstand massive amounts of torque.

Assuming that doesn't happen, sequential (I assume you're talking about clutchless manuals ala BMW's SMG II) are the wave of the future.

Quick rundown:

CVT: Has no gears, adjusts the gear ratio by means of a belt (or chain, in Audi's case) and pulleys. All the efficiency of a manual and can accelerate a bit faster due to the fact that under hard acceleration it brings the RPMs to the power peak and leaves them there while it adjusts the gear ratios for acceleration.

Sequential:Clutchless manual means all the parts of a manual transmission - clutch pedal + hydraulics to operate clutch plates. BMW's SMG II can execute shifts in like 15 milliseconds, much faster than any human could. Also can do seamless downshifts and has an auto mode for when you don't want to hit the paddles to shift yourself.


There are already CVT that can withstand lots of torque in Japan. Nissan Gloria (or Cima) in Japan.

Sequential still operates with a clutch. The difference is that the driver doesn't control it. Seamless downshift is just revv matching which any driver can do, although it would be slower than a computer of course.

I never said sequential didn't have a clutch, only no clutch pedal. Sequentials can do a seamless downshift (by rev matching, yes) every time, and more perfectly than 98% of the drivers out there (myself included).

Link to the Gloria's CVT specs?

Ok. You mentioned clutchless manual so I thought you meant no clutch.

"If Audi?s Multitronic is an evolution of the conventional CVT, Nissan?s Extroid is obviously a revolution. Instead of using a belt or chain as the media for varying transmission ratio, it uses two pairs of rollers. As shown in the picture, the rollers link between the input disc (which connects the crankshaft) and output disc (which connects the driveshaft). By varying the angle of rollers, different transmission ratio can be obtained. For example, for "low" gearing ratio, the rollers meet the input disc near its inside diameter, but meet the output disc near its periphery; thus the output disc turns much slower than the input disc. The overall ratio range is 4.4:1.
Compare with belt or chain, the solid rollers can withstand much higher torque. Moreover, since the input and output disc are located at the same axis, it is able to be packaged in a longitudinal gearbox and drive the rear wheels. In fact, it is already driving the Cedric / Gloria in Japan, handling the massive 286 lbft of torque from the turbocharged VQ6.

The rollers are actuated by electro-hydraulic. However, the rollers are not directly contact with the input / output disc. A specially developed viscous oil provides the traction between them while reduce friction and wearing.
Like other modern CVTs, it also provides 6 artificial sequential ratios for more driver involvement.

Link to transmissions


Nissan's CVT can handle more torque and works with an AWD setup unlike Audi's. However, Audi's CVT has a wider range of available gear rations.
 

StrangeRanger

Golden Member
Oct 9, 1999
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The new CVT systems whoop smg ass. You really gotta try one for a long drive to see what it can do. As far as handling tourque, read up on Audi's CVT drive trains. AMAZING stuff. I sell Audi's and have had a lot of time to beat on their CVT's and have been very impressed. I still like manual trannys tho, it's more fun to row thru the gears.
j
 

KingNothing

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Apr 6, 2002
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Originally posted by: bolido2000Ok. You mentioned clutchless manual so I thought you meant no clutch.

"If Audi?s Multitronic is an evolution of the conventional CVT, Nissan?s Extroid is obviously a revolution. Instead of using a belt or chain as the media for varying transmission ratio, it uses two pairs of rollers. As shown in the picture, the rollers link between the input disc (which connects the crankshaft) and output disc (which connects the driveshaft). By varying the angle of rollers, different transmission ratio can be obtained. For example, for "low" gearing ratio, the rollers meet the input disc near its inside diameter, but meet the output disc near its periphery; thus the output disc turns much slower than the input disc. The overall ratio range is 4.4:1.
Compare with belt or chain, the solid rollers can withstand much higher torque. Moreover, since the input and output disc are located at the same axis, it is able to be packaged in a longitudinal gearbox and drive the rear wheels. In fact, it is already driving the Cedric / Gloria in Japan, handling the massive 286 lbft of torque from the turbocharged VQ6.

The rollers are actuated by electro-hydraulic. However, the rollers are not directly contact with the input / output disc. A specially developed viscous oil provides the traction between them while reduce friction and wearing.
Like other modern CVTs, it also provides 6 artificial sequential ratios for more driver involvement.

Link to transmissions

I did define what I meant by clutchless manual. ;) :p

286 lb-ft isn't bad, but regular manuals and sequentials can still handle a ton more.
 

Bignate603

Lifer
Sep 5, 2000
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I think CVTs are more efficient in using an engine most efficiently but I think the torque problem holds it back.
 

KingNothing

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Apr 6, 2002
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Originally posted by: Bignate603
I think CVTs are more efficient in using an engine most efficiently but I think the torque problem holds it back.

By George, I think he's on to something!
 

bolido2000

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Dec 3, 2001
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Originally posted by: Jellomancer
If an SMG can only handle 280lbs... why not use two sets of pulleys instead of one?

CVT can handle 280lbs so far. CVT' will keep improving and will be able to handle more torque in the future. In Japan mini cars are offered with CVT's and not SMG. Although SMG is prolly cheaper to make. I always thought SMG would make more sense, but it seems like automakers are opting for CVTs.