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Scania old 730 with 12 speed takes more time in higher gear to get to speed from full stop compared to volvo.


McLaren2876

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I have a new volvo 750hp manual (latest model) and a scania streamline with 730hp manual.When I  try to accelerate in the scania in 4th gear or higher gear from a full stop it takes a fair amount of time to get to speed but when I do the same in volvo in 4th gear or higher gear  I takes much less time to accelerate from full stop.Also in scania when I press the accelerator key the rev needle drops,then rises slowly.I dont get the feeling of power.Whereas In volvo when I tap the accelerator key it instantly surges forward with delay with feeling of huge power.Im trying to say that in the scania when I press the accelerator button It dosent go forward instantly and takes more time to reach  to speed but in volvo when I press the accelerator button It surges forward with any delay and with strong power and reach the speed early .The transmission in scania I think is not good or responsive.   Have you guys encountered this problem?

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I drive both volvo and scania but the volvo picks up instantly in high gear but scania takes time and it doesn't instantly kick down the power like volvo.Also when I press the accelerator key in scania the rev needle first dips and then increases and this causes it not to instantly response and in volvo when I press the accelerator key the rev needle doesn't decrease like scania and this causes volvo to kick down instantly.   And another question 6 speed or 12 speed scania is faster with no load and with load. PLEASE BRO INVITE YOUR OTHER FRIENDS OR PLAYERS TO ANSWER THE QUESTION.

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Hey, I'll try to explain why you experience a slower acceleration with the Scania Streamline 12 speed (direct drive) in 4th gear compared to a Volvo FH12 2012 12 speed (direct drive). If you are good with mathematics, that's good, if not, I hope I will not give a headache.

 

Transmissions play a very important role when it comes to acceleration. But first, you need to understand what is a gear ratio. A ratio of 14.94 for example means that the input will make 14.94 revolutions to make 1 output revolution. The higher the number, the higher the torque, the slower the max speed. Certain transmissions will accelerate better than others with light load, but will struggle to get started with heavy load on a steeper hill.

 

The Volvo FH12 2012 with 12 speed has a 4th gear ratio of 7.09 : 1, with a differential ratio of 2.64 : 1.

For one full revolution of wheels, the engine will make 18.7176 revolutions.

The Scania Streamline with 12 speed has a 4th gear ratio of 5.823 : 1, with a differential ratio of 2.71 : 1.

For one full revolution of wheels, the engine will make 15.78033‬ revolutions.

 

The Volvo FH16 750 HP engine has an optimal torque range between 1050 - 1400 RPM.

The Scania Streamline 730 HP (Euro 6) engine has an optimal torque range between 1000 - 1400 RPM.

 

We'll assume the drive wheels are 3180 mm diameter.

The Volvo will reach between ~33.63 km/h to ~44.83 km/h in its optimal torque range in 4th gear.

The Scania will reach between ~37.99 km/h to ~56.98 km/h in its optimal torque range in 4th gear.

 

The weight of the chassis of these trucks vary a little bit, but we will neglect those values. From the looks of it, the Scania will reach a higher speed on 4th gear, but will have slower acceleration. The Volvo will take less time to reach the speeds within its optimal torque.

 

On another note, the newer Scania with 12 speed will shift faster on automatic transmission (at 0.7 the normal shifting time). That is why they are faster than normal 12 speed older Scania and any Volvo with 12 speed transmissions, despite that the newer Scania trucks are heavier. Also with some more testing I've done before, the 6 speed transmission is considerably faster than any other transmissions on a relatively flat road and with lighter load. They take about 3-5 seconds less time to reach from 0-90 km/h on a flat road, depending with which transmissions you compare it to, and what trailer + cargo you have. But the 6 speed transmissions are not very good at going uphill with heavier loads.

KkdaC1b.png

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@McLaren2876 It depends on how heavy the load it, and if the road has lots of hills. The 6 speed will still beat the 12 speed on a flat road, but as soon as you reach a hill, that's when you will realize that the 12 or 14 speed would have been best with such heavy load.

 

Someone has done some testing with a 6 speed vs 14 speed:

 

I hope that helps you understand better.

KkdaC1b.png

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  • 2 weeks later...

Hello,

 

Firstly, thank you for creating a thread on our forum. Sadly, it has been 14 days since the last reply.

 

For the reason stated above, I must lock and archive this thread to keep our forums organized.

 

Kind Regards,
Chev
Community Moderator

 

//Locked & Archived.

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