[slamnos]

Originally Posted by noopster

This car didn't have a manual mode either, nor a Sport mode (the new Nissan Sunny CVT comes with one, though fat good I see it doing!)

Hi noopster, want to correct you on this. Micra CVT always came with Sports mode since launch and its even visible as a small button on the stick (also visible in the pic posted by you).

[noopster]

Originally Posted by slamnos

Hi noopster, want to correct you on this. Micra CVT always came with Sports mode since launch and its even visible as a small button on the stick (also visible in the pic posted by you).

Thanks. I rechecked with our official review and this is indeed the case. I got misled by the fact that there is no 'S' mode in the transmission options.

Though this has got me wondering now...why is Sunny advertising the Sports mode so late?!!

Originally Posted by Ram R.

"Honda’s new City CVT now gets a torque converter along with the usual pulleys-and-belts business".
- The Source and Full Review:
http://www.topgear.com/india/our-car...s/city?id=2826

There's so much growth in automobile technology and technology in general, that it's a challenge just to keep up with the updates.

CVTs have evolved big time, and this article kinda proves it. In fact, I rate the modern CVTs a notch higher than the other automatics out there.

The exact quote is:

Honda’s new City CVT now gets a torque converter along with the usual pulleys-and-belts business. It replaces the old dual-clutch ’box, which was marred by sluggish acceleration, and felt too strained up the rev band. And via various other advancements, Honda has made the new CVT lighter by 10 per cent.

As far as I know, the City never had a "dual-clutch box"- previous generation was 5-speed torque convertor. Also don't know why he says the new City has a torque convertor when Honda themselves call it a CVT.

Much confusion! Is Top Gear getting it wrong or have things really got so complicated in the slushbox business?

[jfxavier]

Thanks noopster for the report.

As I understand, the main point where the existing "manual" users get confused/ unhappy is the lack of clutch pedal and the requirement to lift off from accelerator pedal completely before changing the gears.
In my opinion, the zero throttle position input to ECU or a limit switch on the throttle pedal must be used for activating the clutch.
As some of us like not to lift off completely or like to keep the revs up a bit while engaging the next gear, it might be irritating a bit.
However the makers could use a limit switch on the clutch pedal to replace the zero throttle position requirement and provide the same result, but with increased driving pleasure for the existing "manual" users.
The physical exertion on the left leg also will not be an issue if the limit switch is all that has to be activated instead of de-clutching the transmission.
Maybe then the half throttle gear changes will also be possible for the enthusiastic driver.

[Wagon R Rocks!]

Originally Posted by naikameya

Help me understand.

Does that mean the clutch is electronically pressed every time you lift your foot off the accelerator? I have an habit of coasting where I do not press any pedal and let the car cruise, this helps improve efficiency. If this is what happens in an ECM setup that would definitely reduce efficiency and might even be annoying.

Also on a downward slope in ghats your car is not in any gear if you lift you leg from the accelerator...isn't that bad?

Or may be this ECM setup doesn't exactly work that way...

The ECM may not necessarily work this way. It depends on a number of factors as to when should the clutch actuation takes place; the main parameters in deciding the clutch actuation are the vehicle speed and the corresponding engine speed. The control logic decides when to actuate the clutch; for example the clutch may not disengage if you release your foot off the throttle at cruising speeds (as the clutch will slip once it engages back at higher engine speeds) but the clutch will definitely be disengaged when you would be crawling in traffic to avoid engine stalling and you are in lower gears. The gear ratio step makes all that difference.

Also, AFAIK you would be saving a little more on fuel when you would be lifting off your foot from the throttle while in gear rather than putting the transmission in neutral. Although the difference in fuel consumption may be very minimal, the fuel economy while coasting in gear would always be higher than while coasting in neutral. That's because when you are in Neutral, the engine needs to be fed with a constant supply of fuel to keep in at idling. But when you are coasting in gear, the engine is driven by the wheels (power reversal) and hence the fuel is not fed during this event. I am not sure about Indian cars to use this logic but this is surely used by manufacturers like Ford, GM.

[tanwaramit]

Originally Posted by Wagon R Rocks!

The ECM may not necessarily work this way. It depends on a number of factors as to when should the clutch actuation takes place; the main parameters in deciding the clutch actuation are the vehicle speed and the corresponding engine speed. The control logic decides when to actuate the clutch; for example the clutch may not disengage if you release your foot off the throttle at cruising speeds (as the clutch will slip once it engages back at higher engine speeds) but the clutch will definitely be disengaged when you would be crawling in traffic to avoid engine stalling and you are in lower gears. The gear ratio step makes all that difference.

How will it decide my behaviour on when I am going to change gears next. As long as my foot is not on accelerator, it may keep clutch engaged thinking I am going to shift up/down OR I am going to press brakes.

Since this system just removes the clutch pedal and not the clutch, so the clutch is working behind the scenes and is actually getting engaged at all scenarios.

It makes me wonder, how much the life of clutch will be? and if clutch overhaul can be done independently without touching this system.

[Wagon R Rocks!]

Originally Posted by tanwaramit

How will it decide my behaviour on when I am going to change gears next. As long as my foot is not on accelerator, it may keep clutch engaged thinking I am going to shift up/down OR I am going to press brakes.

Since this system just removes the clutch pedal and not the clutch, so the clutch is working behind the scenes and is actually getting engaged at all scenarios.

It makes me wonder, how much the life of clutch will be? and if clutch overhaul can be done independently without touching this system.

It depends in which gear are you driving and what is the corresponding engine and vehicle speed. If you already are in top gear, you cannot go further up. But the clutch actuation is driven by the control logic which continuously monitors your engine and vehicle speeds (as disengagement and re-engagement at higher speeds lead to clutch slip and wear) and takes decision on engagement/ disengagement. Some vehicles also have brake pedal position sensor input to calculate the deceleration (which it may compare with corresponding vehicle speed) and decide when it should allow the clutch to disengage.

[Ferruccio]

Originally Posted by noopster

OK then, they challenged me, what would you do to resolve this? How about a straight shifter, I suggested. A linear 1-2-3-4-5 configuration that at least makes the process a bit more fun. Or paddle shifters on the steering!

Great post noopster.

IMHO a linear 1-2-3-4-5 configuration would not be fun for experienced drivers. The current Swift gear arrangement allows me the possibility of skipping gears while downshifting when I need added engine braking (e.g. for the Ghats) or for a quick overtaking maneuver on a highway. A sequential / linear 1-2-3-4-5 does not allow that flexibility.

While I agree it will be weird to remember to lift-off the foot from the Accelerator pedal every time to shift the gear, IMHO it will take a few days to get used, that's all. I for one have a painful left knee whenever my driver takes the day off and would love this solution as a retrofit on my Safari or even on my next car.

I have driven the entire gamut of AT options in India and abroad and sincerely feel that of all the options, the one that will reach the tipping point for the Indian mango-man needs to be 1) Cost effective 2) Fuel efficient 3) Reliable.

This solution has that potential. A big thumbs up from me in case the Shaeffler chaps are reading. I will happily pay Rs. 20,000 extra at retail level for this feature.

[SDP]

Don't know how I missed this thread till date.
After reading about the ECM, there was a sense of deja vu.

Originally Posted by SDP

#1 Why clutch pedal?

Learning to drive a manual geared car is a decently daunting task (for most people who don't live and dream cars). Depress the clutch pedal, shift the gear and then release the clutch pedal SLOWLY and press the gas-pedal SLOWLY at the same time. Just too many things to do and needs a good amount of coordination.

I have always wondered if all that circus is really necessary. Yes, I have heard about automatic gearboxes, which can choose and change the gear for you. I am not talking about that. Lot of us just love the stick-shift, why should a computer decide which gear in which my car should run? The point over here is why can't the car be designed in such a way that there is a stick-shift, but no clutch pedal? When the driver slots the car in let's say 2nd gear using the stick, let the clutch disengage automatically, then the 2nd gear-ratio would be set automatically and the clutch would be engaged once again, all in one smooth action because the car would be doing it and not the driver.

No more stalling and no more riding the clutch!

The original post is here:
http://www.team-bhp.com/forum/techni...ml#post2621944

BTW, that post is 3.5 years old.

[noopster]

Originally Posted by Ferruccio

IMHO a linear 1-2-3-4-5 configuration would not be fun for experienced drivers. The current Swift gear arrangement allows me the possibility of skipping gears while downshifting when I need added engine braking (e.g. for the Ghats) or for a quick overtaking maneuver on a highway. A sequential / linear 1-2-3-4-5 does not allow that flexibility.

True. Plus it would totally defeat the purpose of an ECM since the cost involved in changing the shifter would be prohibitive.

This solution has that potential. A big thumbs up from me in case the Shaeffler chaps are reading. I will happily pay Rs. 20,000 extra at retail level for this feature.

Oh trust me they are! And am sure they're heartened by the opinions of you and several others here. Even if there is a niche segment to which the ECM appeals, it may be a worthwhile investment especially in the A/B segments!

[svsantosh]

Though a Apple to Chalk Comparision, this reminds me of the step-thru mobike segment like Hero Street and TVS Jive (IIRC).

No clutch, just step on the gear pedal, and some smart-shifter inside the GB does the work.

Sadly, it didnt work in India.

One Sees a Gear Stick - One Expects a Clutch Pedal/Lever - Period

[low_rider]

AFAIK, a similar concept of clutchless gear-shift was launched by Hero-Honda in their two wheeler "Street" in 1997. But the concept was not adopted by mass market users, maybe due to the styling of this bike (moped type) or maybe the users didn't perceive this to be of sufficient use.

Coming to cars, there are majority of people who question the need for auto transmission (I had everyone in my circle asking me as to why I need an automatic). These people are happy with manual clutch and will not pay extra for ECM/AT which they consider useless.

The second category of people (albeit minority), are those who definitely want an automatic, and for them ECM doesn't suffice in place of full AT.

[k_ajay]

If I understood this ECM right, this should be a fun solution, no? Imagine quick slotting of slick shifts without pressing the clutch. Left leg is saved without forfeiting any of the fun.

Of course, if the ECM can keep up with fast shifts.

Am I the only one thinking this ECM may be good (imagine this on cars like MS Swift, Polo)?

[vijaycool]

Instead of creating confusion between gear shifting and idle left leg. Engineers can easily adopt simple resistance pot in the dummy clutch pedal. Driver can press the clutch pedal which in turn electronically actuate the clutch. clutch pedal action will be pretty light as it not directly controlling the clutch. The resistance in varied degrees can easily cope up with Half clutch manners when needed. Also they can add a simple button with bypass this operation and do the conventional ECM stuff (no clutch). This idea will give ECM a push for sure

[shashanka]

Originally Posted by noopster

With all the foreplay done, now came the time for the main act!

Test Drive #5: Maruti Swift 1.4 + ECM

Cheap innuendos apart,all these technologies leads to a fuel saving of ten percent.

Great thread noopster - you have captured the mind-state and sentiments of the vast majority of drivers here. I have never driven any form of auto box yet, but being a dedicated gearhead have been swallowing the various systems hook, line and sinker. But you have very neatly captured just what someone like me would be up against in such a situation. Extraordinary bit of writing!

Thanks again,
Shashanka

[naikameya]

Originally Posted by Wagon R Rocks!

The ECM may not necessarily work this way. It depends on a number of factors as to when should the clutch actuation takes place; the main parameters in deciding the clutch actuation are the vehicle speed and the corresponding engine speed. The control logic decides when to actuate the clutch; for example the clutch may not disengage if you release your foot off the throttle at cruising speeds (as the clutch will slip once it engages back at higher engine speeds) but the clutch will definitely be disengaged when you would be crawling in traffic to avoid engine stalling and you are in lower gears. The gear ratio step makes all that difference.

May be that is the logic in Dual Clutch systems where it is important to know whether you are going to upshift or downshift. ECM is not an automated gearbox. Simply put it is automatic clutch.

I think this ECM setup should have sensors that simply detect when you use the gear lever and attempt to change gear...but I am not sure of this logic hence requesting someone who exactly knows how this system is engineered.