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So, just throwing out an idea to see if anyone else can think of some practical uses for the idea and whether we might see a "manual CVT" in the future.

I know I've read probably a thousand times "I'll never touch a CVT because I like control over my car, so I drive a manual transmission", but what do you naysayers have to say about a CVT you can actual control with a shifter that has a continuous range to match the CVT (rather than discrete gears)?

Personally, I think it would be too complex for most people (or people period) to use effectively since a manual transmission typical has less than 10 gears and opening up the range to a more continuous range (1-1000 say), you would probably end up feeling for discrete gear positions for certain speeds within the continuous range anyways (but you could shift gradually between them to stay in the power band). In this sense, I think it would be kind of gimmicky (but then again, so are our current paddle shifters for a lot of people too).

One area that I can think the idea might take is a CVT-based sports car (if they beef up the CVT to mate with more powerful engines of course).

What do you all think, is there are a market for a manual CVT? Apart from saying "it's useless, it's stupid, and there's no need for that", are there any practical applications you can think of?
 

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So, just throwing out an idea to see if anyone else can think of some practical uses for the idea and whether we might see a "manual CVT" in the future.

I know I've read probably a thousand times "I'll never touch a CVT because I like control over my car, so I drive a manual transmission", but what do you naysayers have to say about a CVT you can actual control with a shifter that has a continuous range to match the CVT (rather than discrete gears)?

Personally, I think it would be too complex for most people (or people period) to use effectively since a manual transmission typical has less than 10 gears and opening up the range to a more continuous range (1-1000 say), you would probably end up feeling for discrete gear positions for certain speeds within the continuous range anyways (but you could shift gradually between them to stay in the power band). In this sense, I think it would be kind of gimmicky (but then again, so are our current paddle shifters for a lot of people too).

One area that I can think the idea might take is a CVT-based sports car (if they beef up the CVT to mate with more powerful engines of course).

What do you all think, is there are a market for a manual CVT? Apart from saying "it's useless, it's stupid, and there's no need for that", are there any practical applications you can think of?
What little I know about the CVT has been gained from watching You Tube videos. Apparently the CV part is just hooked to a torque converter, instead of the gear set of an ordinary automatic. I therefore assume you're talking about mating the CV portion to a clutch....which then reverts to the question of how gears are selected. Maybe what would make the manual CVT different would be the ability to program the ratios yourself, since they could be set anywhere within the limits of the transmission. Of course, the number of optimal ratios would be pretty limited, so the whole concept of the CVT might be best as an automatic after all.
 

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What little I know about the CVT has been gained from watching You Tube videos. Apparently the CV part is just hooked to a torque converter, instead of the gear set of an ordinary automatic.
Not quite. The CVT has two pulleys. A chain transfers power between them. The pulleys can effectively change diameters, thereby changing the gear ratio.

The pulleys actually gt wider or narrower, and that changes where the chain rides on them. The effect is the same as having a different diameter. The torque converter is only there to keep the engine from stalling. It locks up at a very low speed and stays locked until the engine comes down to idle speed.

Many CVT equipped cars do not have torque converters at all, but achieve the same result using clutches.
 

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...are there any practical applications you can think of?
Not for the OB -- but for high performance cars, acceleration could
be optimized by holding the engine at constant rpm (max hp) while
smoothly advancing the CVT ratio from "neutral" up to top gear.

Problem is, automotive CVTs can't get down to a 0.00 ratio, so
launching from 6000-ish rpm @ 0.0 mph is a bit of a challenge.

There are CVT designs with a continuously variable range extending
through zero (neutral) and including a continuously variable reverse.
Such CVTs do not require a clutch of any kind -- but IAFAIK, none of
this type have been adapted for automobiles.

Looby
 

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To answer an above post, GTR does not have a CVT. It uses a dual clutch automated manual. Mechanically, it's a manual transmission but has an automated clutch.

I picture a manual CVT having a lever that you can adjust forward or backward to select anywhere within the transmission's range of possible gearing. The problem with this is that you would have a hard time controlling speed, since both the throttle and shifter would have analog control over speed.
 

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Discussion Starter #8
I therefore assume you're talking about mating the CV portion to a clutch....which then reverts to the question of how gears are selected.
In regards to this statement, I was thinking more along the lines of what jonlong says:

I picture a manual CVT having a lever that you can adjust forward or backward to select anywhere within the transmission's range of possible gearing.
I would imagine such a shifter to be electronic instead of a mechanical part that controls the CVT in much the same way the computer currently controlling the CVT in auto mode does.

Not for the OB -- but for high performance cars, acceleration could
be optimized by holding the engine at constant rpm (max hp) while
smoothly advancing the CVT ratio from "neutral" up to top gear.

Problem is, automotive CVTs can't get down to a 0.00 ratio, so
launching from 6000-ish rpm @ 0.0 mph is a bit of a challenge.

There are CVT designs with a continuously variable range extending
through zero (neutral) and including a continuously variable reverse.
Such CVTs do not require a clutch of any kind -- but IAFAIK, none of
this type have been adapted for automobiles.

Looby
Good information--thank you for the insight, Looby. If the only goal for a high performance car is to hold the engine at constant RPM, then the car's computer could theoretically do a better job of this in a track situation without hills or other severely varied road gradations, no?

Your comments do bring to mind that a continuous gear ratio selector is a rather abstract concept though. So how about, rather than having a continuous gear ratio selector having a continuous RPM selector (same type of continuous electronic controller, just different logic) and let the gear ratios be computer-controlled to best maintain the selected RPM depending on what the accelerator is doing. This might be too much of a mindset change for drivers though to make it practical to adopt, especially when car computers in a few years will already be adapting your RPM, engine speed, and otherwise by using information about changes in road gradation (using image processing, radar/lidar, and/or localized GPS information about elevation to determine road gradation changes). To be honest, I'm surprised this isn't something they tried to incorporate into EyeSight and other adaptive cruise control systems yet since it's roughly the same complexity of the other features they have made available. Probably some holder is still hoarding the patent and refusing to license at a reasonable enough price to let us small folk have access--even though the technology itself is not prohibitively expensive. A quick search turned up the following patent: Patent US6374173 - Terrain adaptive cruise control - Google Patents At least it's due to expire in 10 years...
 

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Given a CVT that could handle the power, I could see one being good on one of those 80's style turbocharged cars - the ones with a small engine and big turbo, with big turbo lag but big power. With a CVT the engine could quickly rev up to full boost, and stay there as the car accelerated without losing boost during the shift.

I don't think a continuously-variable shifter would be practical to use; figuring out how many gears to downshift when entering a curve is hard enough with a standard 6-speed manual. But the CVT could be programmed so that instead of giving the user 6 fixed gears, maybe the downshift paddle drops the revs by 1000 rpm, and the upshift paddle increases them by 1000 rpm. In such a shifter the ratio between the "gears" would change depending on how fast you are going, but it would be trivial to tell exactly what that engine would be doing after the shift (with the fixed-speed setup it's a bit of a guess, and needs a fair bit of experience with the transmission). Since it's a CVT the wheels don't lose power during the shift. And since the ratios would vary depending on the speed, even frequent use of the manual mode won't result in localized wear on the transmission's cones.
 

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If the only goal for a high performance car is to hold the engine at constant
RPM, then the car's computer could theoretically do a better job of this in a
track situation without hills or other severely varied road gradations, no?
Yes. A computer could easily do a better job at holding constant rpm --
regardless of severe road gradations. Humans with a conventional MT
are better at anticipating gear changes (IMO, the #1 major weakness
of automatic transmissions) but holding constant rpm doesn't require
any look-ahead capability.

Looby
 

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I'm a bit confused. Are you asking for a CVT with a Clutch? Or a CVT with more gears?

If you mean a CVT with a clutch that you can have a wider selection of gears, then I don't see how this is different from a 8 or 10 or 12 speed manual transmission. Personally I prefer a MT due the fact that I can shift through a few gears and gain the performance I want.

If you mean a CVT that you can manually adjust the gear ratios to meet your needs, I don't see how a human could do a better job than a computer. Anyone wanting a MT for the "sport" aspect isn't going to want to shift through countless gears. If you want it to optomize performance, I think Looby hit the nail on the head. A computer could hold the rpms better than a human could.

As far as using adaptive technologies to better anticipate the terrain to maintain a set RPM.. That makes it even more Automatic, as the computer is deciding what to do. If you are implying that allowing the driver to choose what RPM to hold to makes it a MT, then it's no different than the current AT with paddles that let you decide what gear to hold to. You can manually choose the options, but the car engages them.. just semantics.

I don't understand a CVT well enought to understand how you could mate a clutch to it and allow you to slide through gear ratios at your pleasure. But even if you could move the shifter to any infinite gear ratio, it would be pretty hard to know what accelerator input to give to maintain performance at said ratio (as someone has pointed out).

With a true MT you know what gear you are getting and how to apply fuel when you release the clutch. Your mind can process 5 or 6 gear inputs. 100 would be pretty tough.
 
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