Acceleration -- CVT vs auto

[Passion]

On 12/6/2020 at 1:15 AM, Eaststargrouper said:

so you think DCT and automatic have no power loss  with 100% efficiency? fat hope! btw 10% loss where you get this figure from? 

If you change gear from 1st to 2nd, 2nd to 3rd, 3rd to 4th, 4th to 5th and so no, Dual Clutch and Automatic will have delay either if you hard accelerate. The delay in CVT is more or less due to software programmable to reduce slippage under high torque from engine

 

So is CVT good? Honestly, want to longevity of gearbox, then smooth delivery of power is a must. 
 

Quote and unquote from this guy in Malaysia, Audi DCT when press down the accelerator, it will boom! And speed off. Mercedes and BMW DCT, it will slowly deliver the power. Whose gearbox last longer? No need to say also know. But who can move off the line faster? No need to say also know. 

so you are right. It’s the programming. And you are also right that everything has power loss. What I want to correct you is DCT has lesser power loss due to the set up. It’s just like GDI vs MPI, GDI gets more out of the petrol while MPI don’t. Reason why? GDI engine spray direct into the chamber, with minimum loss, while MPI inject along the rail and let it combust. So which one more efficient? Same for gearbox, the torque converter take in 100% energy, itself need to spin, will take out say 10% energy away. Left with 90% for output. DCT on the other hand, take in 100%, because there’s no redundant parts in between, 100% in May result in 95% out. So it’s more efficient. To make the most efficient car, pair a DCT to a high compression engine like skyactiv. You will get the best performance.

[Didu]

3 hours ago, Passion said:

So is CVT good? Honestly, want to longevity of gearbox, then smooth delivery of power is a must. 

It depends on your definition of "smooth delivery of power".

If you define it as not being able to feel the change in gears as your speed increases, then both DCT & traditional autobox will fail you.

If you define it as the vehicle speed increase proportional to gas pedal travel, then CVT will also fail you.

[Didu]

Some car company chooses CVT, some go for DCT, some stick with auto. There's no right or wrong. Buyers just need to choose the type that appeals to them most.

Edited December 7, 2020 by Didu

[Eaststargrouper]

BMW has never won championship in F1 big big. So how good could their engine and gearbox in real field racing be. 

[Contipro]

3 hours ago, Didu said:

Some car company chooses CVT, some go for DCT, some stick with auto. There's no right or wrong. Buyers just need to choose the type that appeals to them most.

i dont trust what Mazda said anymore. 
last time said want perfecting the NA engine only as they believe this is the direction of future . Eventually now still resorted to turbocharged engine.

Mazda focus on best handling, but because to save cost. Drop the multi link suspension switch to torsion beam. 

As for their gearbox, if long term the economy of scale cannot be achieved, i believe they will soon drop this auto gearbox as well. 

let see... may be i am right, may be i am wrong.. 

 

 

 

[ER-3682]

7 hours ago, Eaststargrouper said:

BMW has never won championship in F1 big big. So how good could their engine and gearbox in real field racing be. 

F-1 Cars Engine & Gearbox are 100% not the same as Road Going Cars,cannot compare like this...Take Mercedes Benz F-1,they may be World Champion,but do you find any bits of F-1 Parts in their Mass Production Cars.?Nope...only thing can find the same is the 3 Pointed Star Logo.😆

[ER-3682]

7 hours ago, Contipro said:

i dont trust what Mazda said anymore. 
last time said want perfecting the NA engine only as they believe this is the direction of future . Eventually now still resorted to turbocharged engine.

Mazda focus on best handling, but because to save cost. Drop the multi link suspension switch to torsion beam. 

As for their gearbox, if long term the economy of scale cannot be achieved, i believe they will soon drop this auto gearbox as well. 

let see... may be i am right, may be i am wrong.. 

 

 

 

Torsion Beam Rear Suspension only on based model Mazda 3,the Mazda 6 still using Multi Link Suspension.

[Gew]

The "clutch-lessness" per se is told to achieve the best acceleration nowadays.

Can't say if it's true though, I only drive stick.

[inlinesix]

8 hours ago, Eaststargrouper said:

BMW has never won championship in F1 big big. So how good could their engine and gearbox in real field racing be. 

BMW wins DTM that’s based on road going car.

 

[Passion]

15 hours ago, Didu said:

It depends on your definition of "smooth delivery of power".

If you define it as not being able to feel the change in gears as your speed increases, then both DCT & traditional autobox will fail you.

If you define it as the vehicle speed increase proportional to gas pedal travel, then CVT will also fail you.

Smooth means it doesn’t send the wheel screeching when accelerate hard. Of course you can say that’s good traction control... those who driven the big 3 German conti will know what I mean 

[Didu]

2 hours ago, Passion said:

Smooth means it doesn’t send the wheel screeching when accelerate hard. Of course you can say that’s good traction control... those who driven the big 3 German conti will know what I mean 

Yep, you're someone who knows what you want all the while. 

[Ake109]

On 12/6/2020 at 10:27 PM, Eaststargrouper said:

If your "the electrics coming will lead to a dead end" scenario is true, then it would not be only applicable to CVT but the whole petrol car industry and all other petrol engines related gearbox including DCT, AT and manual all dead.

Yes. But I singled out CVT because compared to manual which has already come to a dead end with the 6 spd, and auto which has matured from rubber band to manual beating, the CVT will not have the time and space to mature.

[Ake109]

5 hours ago, ER-3682 said:

F-1 Cars Engine & Gearbox are 100% not the same as Road Going Cars,cannot compare like this...Take Mercedes Benz F-1,they may be World Champion,but do you find any bits of F-1 Parts in their Mass Production Cars.?Nope...only thing can find the same is the 3 Pointed Star Logo.😆

As far as I am concerned, F1 is waste money rich man plaything.

DTM, WRC (those homologation days was so fun) and Le mans much more rooted to road cars and even then, very little makes it thru to road cars.

 

[Hamburger]

And the saga of this transmission thingy goes on.... 

Folks, it's the engine that matters. 

I had a lancerCS3 5 sp stick and it's slow like nobody business. Cos the 1.6Lengine only produces that much power. 

Now wifey driving a 1.5T Mini w/DCT and is much quicker. Why? Cos engine more power!! 

 

[Rickster]

20 hours ago, Didu said:

It depends on your definition of "smooth delivery of power".

If you define it as not being able to feel the change in gears as your speed increases, then both DCT & traditional autobox will fail you.

If you define it as the vehicle speed increase proportional to gas pedal travel, then CVT will also fail you.

I think it all means different things to different folks.

So there is a market for all transmissions. 😁

[Rickster]

14 hours ago, Eaststargrouper said:

BMW has never won championship in F1 big big. So how good could their engine and gearbox in real field racing be. 

So does that make Renault good cars? They have won F1 big big for a period of time ma. Even the mighty Schumacher + Ferrari cannot beat Renault + Alonso.

I don't think F1 performance are that closely related to the road vehicles we are driving.

[Rickster]

6 hours ago, ER-3682 said:

F-1 Cars Engine & Gearbox are 100% not the same as Road Going Cars,cannot compare like this...Take Mercedes Benz F-1,they may be World Champion,but do you find any bits of F-1 Parts in their Mass Production Cars.?Nope...only thing can find the same is the 3 Pointed Star Logo.😆

Talking about that, back in 2005 when my family owned a Renualt Megane, they (Renault) are so proud of their F1 heritage that they say these technologies flow down to their road cars.

When i asked what exactly flowed down? Its the hole for fuel pump to go in. Normal cars have a cap u have to unscrew, but for Renault cars, its some sort of a spring loaded mechanism when u use the fuel pump nozzle to press against it, it will open. No need to unscrew the fuel cap....so much for F1 technologies that goes into their road cars 

Edited December 8, 2020 by Rickster

[Rickster]

14 minutes ago, Hamburger said:

And the saga of this transmission thingy goes on.... 

Folks, it's the engine that matters. 

I had a lancerCS3 5 sp stick and it's slow like nobody business. Cos the 1.6Lengine only produces that much power. 

Now wifey driving a 1.5T Mini w/DCT and is much quicker. Why? Cos engine more power!! 

 

Yes, the engine is indeed important. However, I would say gearbox is the other half of the story.