Acceleration -- CVT vs auto

[Contipro]

2 hours ago, Passion said:

You put a 241hp car on dual clutch, you see who go faster. It’s not the gearbox now, it’s the engine pack with power and that’s why the pull force is amazing.

You have answer the mystery that everyone debating.

it down to engine power for how fast the acceleration, not the gearbox.

finally someone know what he talking about.

great work!!

[Eaststargrouper]

The gearbox does make a lot of difference in how car shift gear, and thus how car perform and accelerate, why not?  If one is talking about 0-100km acceleration, of course not much difference. Because most sports car can do century sprint within the 1st or 2nd gears, no or much gear shift involved.

But if one is talking about scenarios beyond and requiring shifting of gears up and down frequently then there is a lot difference. A lot of people is fascinated by the name dual clutch transmission but it is nothing more than 2 half set of manual gears. In most budget models, it is cheaper to produce than a CVT gear box.

[Passion]

18 hours ago, Eaststargrouper said:

The gearbox does make a lot of difference in how car shift gear, and thus how car perform and accelerate, why not?  If one is talking about 0-100km acceleration, of course not much difference. Because most sports car can do century sprint within the 1st or 2nd gears, no or much gear shift involved.

But if one is talking about scenarios beyond and requiring shifting of gears up and down frequently then there is a lot difference. A lot of people is fascinated by the name dual clutch transmission but it is nothing more than 2 half set of manual gears. In most budget models, it is cheaper to produce than a CVT gear box.

What scenario require shifting of gear up and down so frequently? Unless when you want to overtake? Then it’s back to the engine power again. Without a powerful output from the engine, no way a car can accelerate fast enough. Nothing to do with gearbox. You put 2 cars with different gearbox, cvt and auto and DCT, it’s not 100% cvt will accelerate faster. It’s when the car engine can reach the max torque. You drive a turbo charged engine, the max torque comes in at 1.5k rpm, give you a cvt also can be faster than a non turbo car who’s max torque only at 4K rpm but with a DCT. 

what I’m trying to say is, it’s the engine. Turbo engine has max torque earlier thus acceleration is faster, regardless what gearbox its pair with. 

Edited December 4, 2020 by Passion

[andrewyewkc]

19 minutes ago, Passion said:

What scenario require shifting of gear up and down so frequently? Unless when you want to overtake? Then it’s back to the engine power again. Without a powerful output from the engine, no way a car can accelerate fast enough. Nothing to do with gearbox. You put 2 cars with different gearbox, cvt and auto and DCT, it’s not 100% cvt will accelerate faster. It’s when the car engine can reach the max torque. You drive a turbo charged engine, the max torque comes in at 1.5k rpm, give you a cvt also can be faster than a non turbo car who’s max torque only at 4K rpm but with a DCT. 

what I’m trying to say is, it’s the engine. Turbo engine has max torque earlier thus acceleration is faster, regardless what gearbox its pair with. 

Haha, agree exactly, NPNT. Once I tried to overtake driving a CVT car in Malaysia, rpm hit 5000 and I am still far behind tha car I'm trying to overtake. I did this a few more times and later the CVT kaput and need total replacement.

[Toeknee_33]

12 minutes ago, andrewyewkc said:

Haha, agree exactly, NPNT. Once I tried to overtake driving a CVT car in Malaysia, rpm hit 5000 and I am still far behind tha car I'm trying to overtake. I did this a few more times and later the CVT kaput and need total replacement.

Hahaha! You make your CVT gearbox sound like its made out of recycled plastic.

What were you trying to overtake and at what speed? Is it within the capability of your car? Latio at 150kmh trying to overtake Camry at 180kmh?

 

[andrewyewkc]

1 minute ago, Toeknee_33 said:

Hahaha! You make your CVT gearbox sound like its made out of recycled plastic.

What were you trying to overtake and at what speed? Is it within the capability of your car? Latio at 150kmh trying to overtake Camry at 180kmh?

 

I was an early adopter of CVT technology, this was 20 years ago. Not so fast, I was trying to overtake at around 120kmh from around 70?.

CVT technology has improved over the years and has become more reliable. I was quite impressed when I test drove the Forester XT.

[Ake109]

1 hour ago, Passion said:

What scenario require shifting of gear up and down so frequently? Unless when you want to overtake? Then it’s back to the engine power again. Without a powerful output from the engine, no way a car can accelerate fast enough. Nothing to do with gearbox. You put 2 cars with different gearbox, cvt and auto and DCT, it’s not 100% cvt will accelerate faster. It’s when the car engine can reach the max torque. You drive a turbo charged engine, the max torque comes in at 1.5k rpm, give you a cvt also can be faster than a non turbo car who’s max torque only at 4K rpm but with a DCT. 

what I’m trying to say is, it’s the engine. Turbo engine has max torque earlier thus acceleration is faster, regardless what gearbox its pair with. 

I need to nitpick (its a peeve of mine on this topic).

It is not max torque. It is max power which you need for acceleration. Because torque becomes power after multiply by rpm. 

e.g. If you have an engine that gives you 1000Nm of torque but its at 500rpm, you will lose to a 100Nm at 6000rpm engine (all else being same).

A theoretical 100% efficient CVT will accelerate faster at max power rpm, not max torque rpm.

When most people say high torque, what they are referring to is low end torque = low end power.

[Symrise]

Cvt no go

[Stratovarius]

Just look at the specs of wrx. Cvt is slower than mt by 0.3sec. And dct is faster than mt. So yeah, cvt is slower. Good old cvt is usually slower than mt, except for the swift sport where cvt is as fast as mt on paper. 

Unless u bring ur car to track, I don't see any issues with cvt. I kinda like the electric car feel. Lol. Plus fuel efficiency might be more important for some than the 0.X secs faster in acceleration. 

[Eaststargrouper]

6 hours ago, Passion said:

What scenario require shifting of gear up and down so frequently? Unless when you want to overtake? Then it’s back to the engine power again. Without a powerful output from the engine, no way a car can accelerate fast enough. Nothing to do with gearbox. You put 2 cars with different gearbox, cvt and auto and DCT, it’s not 100% cvt will accelerate faster. It’s when the car engine can reach the max torque. You drive a turbo charged engine, the max torque comes in at 1.5k rpm, give you a cvt also can be faster than a non turbo car who’s max torque only at 4K rpm but with a DCT. 

what I’m trying to say is, it’s the engine. Turbo engine has max torque earlier thus acceleration is faster, regardless what gearbox its pair with. 

Refer to my earlier post.

btw thought this thread is about gearbox, not so much about the engine

[Eaststargrouper]

6 hours ago, andrewyewkc said:

Haha, agree exactly, NPNT. Once I tried to overtake driving a CVT car in Malaysia, rpm hit 5000 and I am still far behind tha car I'm trying to overtake. I did this a few more times and later the CVT kaput and need total replacement.

Repeat the same fake "joke" over and over again. Yawn

The reason why you failed to overtake were either because your car had a much smaller engine capacity and hence less power and torque, your driving skill, or type of vehicle may be your car is much heavier than the one you are trying to overtake, etc. All these had nothing to do with the CVT

[Ake109]

In _theory_, a 100% efficient DSG vs a 100% efficient auto vs a 100% efficient CVT, the CVT should win because it can stay at max power while the other 2 need to suffer the rest of the power curve.

Back in the days when CVT was first mooted, I thought it would be like autos, at first slower but get faster and faster thru refinement and tech improvements till  it beats manual. But I think with electrics coming, maybe its a dead end.

[Brass]

10 hours ago, Toeknee_33 said:

Hahaha! You make your CVT gearbox sound like its made out of recycled plastic.

What were you trying to overtake and at what speed? Is it within the capability of your car? Latio at 150kmh trying to overtake Camry at 180kmh?

 

I think Nissan Jatco's CVT are a nightmare, from folklore and many real examples around me. I heard that the CVT in the 3.5L Murano can fail relatively easily due to its power, so people are naturally afraid of the CVT.

Dont get me wrong, I think CVT is a gem on its own, it is the application and quality that counts. If you mate a ZF 8 speeder to a 1.5L vios, I dont think that would better than putting a CVT in it.

On another note, lawnmovers use CVT due to their low cost and fuel efficiency, and resonable durability. If CVTs broke down like nobody's business they would have gone the way of the dodo.

[markw12]

7 hours ago, Ake109 said:

In _theory_, a 100% efficient DSG vs a 100% efficient auto vs a 100% efficient CVT, the CVT should win because it can stay at max power while the other 2 need to suffer the rest of the power curve.

Back in the days when CVT was first mooted, I thought it would be like autos, at first slower but get faster and faster thru refinement and tech improvements till  it beats manual. But I think with electrics coming, maybe its a dead end.

cvt has a 10% power loss. Also I think a slight delay if suddenly hard accelerate.

[Si4dr]

Driving a BnB car and mostly city drive like Singapore, fuel efficiency & reliability are my priority choice.   

The few milliseconds or 2-3 seconds faster is not in my consideration. 

[ferrytales]

to be fair, cvt gives you a smooth flawless drive aka lifeless while the old school auto gearboxes give you more driving feel. personally i will prefer to have the feel of driving rather than a lifeless and soul-less car.

[yellowshaun]

1 hour ago, Si4dr said:

Driving a BnB car and mostly city drive like Singapore, fuel efficiency & reliability are my priority choice.   

The few milliseconds or 2-3 seconds faster is not in my consideration. 

 

16 minutes ago, ferrytales said:

to be fair, cvt gives you a smooth flawless drive aka lifeless while the old school auto gearboxes give you more driving feel. personally i will prefer to have the feel of driving rather than a lifeless and soul-less car.

I guess in SG got two gang of driver:

1. Petrol very expensive so happy to have a more sian drive to save money
2. Spend so much money on car already might as well enjoy the ride, who cares about burning petrol =D

[Contipro]

I thought the topic already come to a conclusion if want fun, then get a more powerful engine...