The new CVS raises the standard of transmission bringing our scale cars into the 21st Century by utilizing the technology as used on pretty much all modern day Full size cars.
The advantage of running constant veolcity driveshafts has been well known for nearly the last 100 years and it is a major factor in maintaining wheel compliance with the ground.
The new shaft provides constant velocity equalising input and output shaft speeds reduces wheel vibration to a minimum providing a much smoother transmission increasing steering and overall grip levels on the car by reducing unwanted tyre scrub.
Using the CVS in both the front and rear of the car provides a more stable and precise car that is easier to drive with the added benefit of improving transmission wind up and tyre wear.
The potential benefit of running constant velocity drive shafts can be seen when looking at the standard UJ.
Theoretically a motor spinning at 40000 rpm with a gear ratio of 7 to 1 will produce a wheel speed of 5714 rpm. At zero angle this will remain at 5714rpm. However introduce angle into the joint and it begins to fluctuate. It is common to run with the drive shafts with some angle given the ride height to diff height toe angle and camber. At 30 degrees (front) the speed fluctuation will be approximately 29% giving an actual speed fluctuation of: 1657 rpm which occurs twice per revolution in both directions.
5714 45 rotation accelerating
7371 90 rotation decelerating
5714 135 rotation accelerating
4057 180 rotation decelerating
5714 225 rotation accelerating
7371 270 rotation decelerating
5714 315 rotation decelerating
4057 0 rotation accelerating
5714 45 rotation
This can produce excessive tyre wear and load the transmission wearing drive shafts, cups, pulleys and belts.
At the same time the rear of the car will also produce some results. Assuming 3 degrees toe in and a shaft operating angle of some 10 degrees there will be an approximate speed fluctuation of 3 %.
That is +/- 171 rpm again in both directions.
Since the suspension on the car is relatively soft every time that car leans in a corner the speed fluctuation is increased maybe up to as much as 12% assuming the angle is now operating at close to 20 degrees.
This is as much as 685 rpm.
For more information please log on to www.quantumracing-rc.com or contact us at enquiries@quantumracing-rc.com
