Constant RPM Gearbox for Diesel Cars: Reviving the DAF Variomatic

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SUMMARY

The discussion centers on optimizing diesel car performance through the construction of a constant RPM gearbox, specifically reviving the DAF Variomatic system. Users noted that diesel engines operate most efficiently at low RPMs, around 1700-2000, but performance declines significantly above 3500 RPM. The conversation highlights the potential of continuously variable transmissions (CVTs) as modern alternatives, with examples from vehicles like the Fiat Punto and Audi A6. Participants emphasize the importance of maintaining optimal torque for fuel efficiency.

PREREQUISITES
  • Understanding of diesel engine performance characteristics
  • Familiarity with continuously variable transmissions (CVTs)
  • Knowledge of gearbox design principles
  • Basic mechanical engineering concepts
NEXT STEPS
  • Research the mechanics of the DAF Variomatic transmission
  • Explore modern CVT technologies and their applications
  • Investigate diesel engine tuning for optimal RPM performance
  • Learn about torque management in automotive engineering
USEFUL FOR

Automotive engineers, diesel vehicle enthusiasts, and anyone interested in improving fuel efficiency and performance in diesel cars.

Andre
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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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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.
 

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