Nissan’s continuously variable transmissions (CVTs) are paired to work with the vehicles’ engine in order to give responsive passing performance. Pulling out to pass another vehicle is a good way to appreciate the responsiveness designed for the engine and transmission.
Nissan introduced the Xtronic CVT ® with the release of the Murano in 2003. It was designed to provide smoother, quieter, and virtually shift shock free transmission performance at higher MPG than the traditional A/T. Now, the Xtronic CVT is found in all of Nissan’s front-wheel drive car models. For sale today - 21610! New 2021 Nissan Sentra Xtronic CVT SR- VIN: 3N1AB8DV0MY203682 at Town North Nissan - New and Used Nissan Dealer Serving Austin, TX.
When you do not need maximum acceleration, the vehicle’s CVT response changes to enhance comfort. Nada dering hp jadul nokia 3310. To demonstrate, while driving safely, accelerate to a speed of 45 MPH (72 km/h). Then, depress the throttle about three-quarters of the way to the floor and accelerate to the speed limit. Notice that the CVT simulates shifts — like a conventional automatic transmission shifting between gears. This provides a more linear acceleration feel and also relieves the engine noise that can come from constant high-rev acceleration.
INTRODUCING D-STEP TRANSMISSION TUNING
Many customers are bothered and have communicated that they believe that their transmissions are malfunctioning due to the lack of a discernible change in gears. D-Step Shift Logic should serve to relieve those concerns by giving drivers a more traditional driving experience.
To give drivers the option of feeling gearshifts while on the road, our Nissan® design engineers have added a D-Step Shift Logic feature to the CVT for many new vehicles in our lineup. D-Step Shift Logic is a software update that will give drivers the feeling that their vehicle is shifting gears like a conventional automatic transmission. The revised transmission tuning provides stepped ratio changes during moderate to heavy acceleration to reduce noise and produce a linear acceleration.
During rapid acceleration, once the vehicle reaches 4,000 RPM such as when merging onto a busy highway, the software commands the electronic brain of the Xtronic CVT gearbox to hold a ratio and then shift. It then helps create a subtle momentary drop in driving force to give a sense of gear change. It allows engine speed to build as vehicle speed builds, which also relieves the engine noise that can come from constant high-rev acceleration.
At cruising speed, the new tuning also allows the transmission to immediately change ratios when quick acceleration is needed, such as to pass another vehicle on a two-lane road.
During normal driving, the transmission retains the smooth, seamless response for which the Xtronic CVT is known.
DEMONSTRATING D-STEP
There is a simple 3-part demonstration that you can use to show customers how D-step tuning adds to the versatility of their transmission. Find a road or empty lot without traffic where you can accelerate from a standing start to accelerate three times – mildly, aggressively, and full-throttle, (make sure to observe the speed limit).
1. Mild acceleration – Press the accelerator no more than halfway, and accelerate as you would in normal city driving. Point out how the engine revs gently and then holds at a steady RPM level as the vehicle accelerates gradually and smoothly
2. Aggressive acceleration – Press the accelerator about three-quarters of the way to the floor. Point out that the engine revs high for strong acceleration. Once the vehicle speed reaches about 40 MPH, the response becomes more like a conventional automatic transmission shifting between gears. The revs drop to about 4,000 RPM and then build to about 5,000 RPM. Then it “shifts” again and repeats the process as long as you continue to accelerate.
3. Full-throttle acceleration – Fully depress the throttle and accelerate to the speed limit. Point out that the engine revs high and maintains an RPM level near the redline for maximum engine response.
The new tuning maintains the Xtronic CVT’s advantages in everyday driving and helps enhance its appeal. It is intended to provide smooth acceleration, keep the engine in its optimum power band, and eliminate “hunting” for the right ratio on hills. When quick or aggressive acceleration is needed, it provides responsive, stepped acceleration with a more linear feel.
Xtronic Cvt Reliability
The Continuously Variable Transmission (CVT) allows engines to work at their greatest potential by freely moving through gear ratios to maximize performance and fuel economy. The advantage of the CVT is that it can choose the optimum transmission gear ratio. Solid gears are a thing of the past. The CVT uses the readings of multiple sensors to keep the engine rotating at a precise number of RPM with two variable pulleys and a steel belt. The system consists of seven smaller systems, including the vehicle’s mechanical, electrical, and oil systems, to provide fuel efficiency and continuous power. The following information on the CVT will guide you through its history, the systems and components involved and their operation.
HISTORY AND EVOLUTION OF CVT
The first visionary that conceptualized a stepless, continuously variable transmission was none other than painter, architect and inventor Leonardo da Vinci. Iron man 2 pc game compressed download. He first sketched a stepless, continuously variable transmission in 1490.
In the centuries that followed, Adiel Dodge received a U.S. patent for a toroidal CVT. It still took years before the continuous variable transmission idea was brought to fruition in sawmills, tractors and motorcycles. Nissan® first used the CVT in the 1992 March, which was a super mini car also known as the Micra. The cube® and the Primera, which was introduced as the Infiniti G20® in North America, also ran with CVTs. After extensive research and development, Nissan developed a CVT that would run in high-torque engines in 2002. Nissan introduced the Xtronic CVT® with the release of the Murano in 2003. It was designed to provide smoother, quieter, and virtually shift shock free transmission performance at higher MPG than the traditional A/T. Now, the Xtronic CVT is found in all of Nissan’s front-wheel drive car models.
Nissan has continued making design changes ever since the CVT first hit the streets in North America. The newest models of this transmission are lighter and shorter and utilize optimum hydraulic control technology, which has enabled their use in a wider range of vehicles. They also have a broader gear ratio range by an entire gear, up to 7.3:1 in some vehicles from 6.0:1, providing fuel efficiency at a greater range of speeds.
CVT BASIC OPERATION
Nissan’s Xtronic CVT is a complex system that involves the use of sensors from the combination meter, the gear shifter and under the hood on both sides of the vehicle.
It is important to understand gears before we move forward. The rotating axes on a bicycle are gears. Imagine the bicycle with just two gear axes, both capable of expanding or contracting to the size of the largest and smallest gears that were on the bike, and you have imagined a continuously variable transmission. The CVT’s gears are capable of changing rotational direction, changing the speed of rotation, and optimally pairing the rotational speeds of the two axes.
When the driver presses the accelerator pedal, this sends a slew of signals to the CVT’s control valve assembly and the Transmission Control Module (TCM). The TCM controls the oil pressure system, which has two valves that control line pressure. The other signals are translated to voltages to activate the entire transaxle, including two variable pulleys and one steel-plated belt. The pulleys constantly adjust themselves to stay in the proper ratio. At around 5 MPH (8 km/h), the lock-up converter and the select control system engages, reducing slippage to get the best possible fuel efficiency. Contributors to the CVT’s functionality include the pulleys, belt CVT control valve assembly, shift lock system, oil pressure control system, fluid warmer system and the lock-up and select control system.
CVT SYSTEMS – Transaxle
Pulleys and Belt – The two pulleys and the belt are the heart of the CVT system. The primary, or drive pulley, connected to the engine lies on the input shaft side. The secondary, or driven pulley, lies on the output shaft side to the drive wheels. There is a cone-shaped slope on the fixation sheave half of the pulley that works with the slope on the mobile sheave halves that can move in the axial direction.
Xtronic Cvt Automatic
The movable sheave slides on the shaft to change the groove width of the pulley. As the pulley sheave halves come closer together and the width of the pulley changes, the belt is forced to ride higher on the pulley, effectively making the pulley’s diameter longer. Changing the diameter of the pulleys varies the transmission’s ratio (the number of times the output shaft spins for each revolution of the engine). Making the output pulley diameter longer gives a low ratio (a large number of engine revolutions producing a small number of output revolutions) for low-speed acceleration.
Xtronic Cvt
Input signals of engine load (accelerator pedal opening), primary pulley speed and secondary pulley speed change the operation pressures of the primary pulley and the secondary pulley and control the pulley groove width. Pp 25 download windows. As the car accelerates, the pulleys vary their diameter to lower the engine speed as the car speed rises, continuously varying the ratio.