Constant RPM Gearbox for Diesel Cars: Reviving the DAF Variomatic

In summary, the conversation discusses the differences between diesel and petrol cars, with diesel engines being more effective at low RPM but less effective at higher RPM. The speaker also mentions the idea of creating a constant RPM gearbox to maintain optimum performance and fuel consumption, and suggests looking into the DAF Variomatic or other continuously variable transmissions. The conversation ends with a link to a Wikipedia article detailing different types of CVTs.
  • #1
Andre
4,311
74
So I'm driving this super mini on diesel and I observe several differences with normal petrol cars.

At low RPM, some 1700-2000 cycles, the engine is super effective, the torque and the excess power is awesome, while the fuel consumption is unreal low. However at higher RPM, this surplus decreases vastly and above 3500 RPM, normal petrol cars seem to prevail for horsepower and fuel consumption. Obviously with a diesel, you'd like to drive at 1800-1900 RPM all time for optimum performance and minimum fuel consumption.

So how to construct the constant RPM gearbox, making sure that the engine runs at optimum torque all the time?

Can we revive the old DAF Variomatic from the moth balls?

http://www.classic-daf.nl/indexb.html
http://www.tocmp.com/pix/Europe/DAF/pages/1962%20variomatic_jpg.htm
 
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  • #2
While the DAF variomatic isn't the ideal setup, there are many cars with continuously variable transmissions (CVTs) available today (from the Fiat Punto to the Audi A6).

This Wikipedia article is excellent for detailing the different types of CVT and their associated mechanisms.
 

1. What is a Constant RPM Gearbox?

A Constant RPM Gearbox, also known as a CVT (continuously variable transmission), is a type of transmission that allows for a continuous range of gear ratios instead of discrete gears. This allows for a smoother driving experience and improved fuel efficiency.

2. How does the Constant RPM Gearbox work?

The Constant RPM Gearbox works by using a system of pulleys and belts or chains to vary the gear ratio. The gear ratio is constantly adjusted to maintain a consistent engine speed (RPM) while the vehicle's speed changes. This eliminates the need for shifting gears and allows for a seamless acceleration.

3. How does the Constant RPM Gearbox benefit diesel cars?

The Constant RPM Gearbox can greatly benefit diesel cars by improving their fuel efficiency. Diesel engines operate most efficiently at a specific RPM, and the Constant RPM Gearbox allows for the engine to stay in that optimal range, resulting in better fuel economy.

4. What is the DAF Variomatic?

The DAF Variomatic is an early version of the Constant RPM Gearbox, first introduced in the 1950s by Dutch car manufacturer DAF. It was one of the first commercially successful CVT systems and was used in their lineup of diesel cars.

5. Why is there renewed interest in the DAF Variomatic?

In recent years, there has been a growing interest in the DAF Variomatic due to its potential to improve fuel efficiency and reduce emissions in diesel cars. With advancements in technology, it is now possible to improve upon the original design and make it more suitable for modern vehicles.

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