This summary of the video was created by an AI. It might contain some inaccuracies.
00:00:00 – 01:15:52
The video provides an in-depth comparison of the Rivian R1T and R1S's dual motor and quad motor systems, focusing on technical aspects, driving experience, and efficiency. It features detailed explorations of both drivetrain configurations, emphasizing the in-house designed dual motor Enduro system, which offers improvements in efficiency, quietness, and smoother operation. The quad motor system, while beneficial for tougher off-road conditions due to its advanced torque vectoring, faces challenges with efficiency and noise.
Key terms discussed include battery pack options (small LFP, middle spec, and Max pack), permanent magnet setups, silicon and silicon carbide motor versions, inverter chassis, and differential locks. Important places mentioned include the Rivian factory in Normal, Illinois, where these innovations are being developed and tested.
Test drives and off-road trials demonstrate the dual motor's advantages in most scenarios, particularly for everyday use and smoother, quieter performance. The quad motor, though powerful and better suited for extreme off-road conditions, has limitations such as increased noise and less efficient thermal management. The video concludes with a recommendation favoring the dual motor system for its practicality and overall efficiency for the average user.
00:00:00
In this part of the video, the presenter addresses the concerns about the video’s length, offering a detailed exploration of the new Rivian R1T and R1S drivetrain options, specifically focusing on the dual motor Enduro system. They plan to compare the quad motor and dual motor systems by driving and towing with both configurations. The presenter is at the Rivian factory in Normal, Illinois, and discusses upcoming improvements and feedback with Rivian engineers. They explain the different battery pack options (small LFP, middle spec, and Max pack) and how the new dual motor system, designed and built in-house, fits into the lineup. The video emphasizes technical details and driving differences between the motor configurations, appealing to a knowledgeable audience interested in in-depth information about Rivian’s offerings.
00:10:00
In this part of the video, the speaker discusses potential updates to the quad motor system and provides details on the currently available systems. The original quad motor, designed by Bosch, has some limitations and inefficiencies. In contrast, the new dual motor system is an in-house design meant to improve efficiency and integration, featuring a dual permanent magnet setup with a primary front and secondary rear axle. The speaker highlights notable features such as a quick disconnect clutch on the rear axle, improvements in efficiency, and quieter operation. Additionally, there are two motor versions, silicon and silicon carbide, each offering different efficiency and cost benefits.
Later, the speaker transitions to showcasing the Rivian R1T truck with a Max pack, detailing its 410-mile range and battery pack changes. A test drive is conducted on Rivian’s test track, highlighting differences in daily driving between the dual and quad motor systems. The dual motor system’s dynamic rear axle disconnect feature optimizes performance and efficiency. Throughout the test drive, various aspects of performance, including regenerative braking and the response of the powertrain under different modes, are explored.
00:20:00
In this part of the video, the discussion centers around vehicle performance and handling, specifically focusing on speed limits, torque limits, and launch techniques. It is mentioned that lower ride heights enable faster launches due to torque limits being dependent on ride height. The segment also includes a detailed comparison of dual motor versus quad motor systems, highlighting aspects such as axle performance, suspension tuning, and the impact on various terrains. The speaker performs a two-foot launch and explains the effects of different driving modes, such as all-terrain and rock crawl modes, on the vehicle’s performance. The video further explores off-road handling, demonstrating how the truck manages obstacles like berms, rock gardens, and steep grades, emphasizing the importance of stability control and the benefits of brake traction control in maintaining torque transfer.
00:30:00
In this part of the video, the speakers discuss and demonstrate the performance differences between dual motor and quad motor systems in trucks. They focus on the regenerative braking (regen) feature, which aids in descending hills and controlling speed. The quad motor system is noted for its refinement, silent operation, and effective torque vectoring, which allows for better handling of tough obstacles and an enhanced driving experience.
They highlight the advantages of the quad motor in off-road scenarios, particularly its ability to overdrive the rear wheels and adjust the vehicle’s yaw balance. The speakers also touch upon the vehicle software improvements, like reducing phantom drain and the convenience of over-the-air updates.
During the test drive, they mention the audible differences between the dual and quad motor systems, with the dual motor having more noticeable gear noise. They also address the clutch disconnect feature and the distinct power responses of both systems, particularly in different driving modes like conserve and all-purpose.
Finally, they showcase the launch performance and discuss the benefits of the quad motor’s torque vectoring in providing better on-throttle oversteer and handling during cornering and off-road conditions.
00:40:00
In this segment, the video compares a dual motor and a quad motor truck, focusing on how they handle various off-road situations. The dual motor is noted for its smoother performance and better handling at low speeds, particularly in crawling scenarios where it easily navigates inclines without much throttle. The quad motor, however, shows strengths in high-speed off-roading but struggles more on steep inclines, requiring more throttle and showing delays in power distribution.
The segment includes a test on a specific hill where the dual motor succeeded effortlessly, whereas the quad motor needed more encouragement but ultimately managed. The discussion highlights issues with torque vectoring when a wheel loses traction and the challenges both systems face when stuck. The quad motor exhibited a more audible noise at low speeds and occasionally required adjustments to overcome obstacles.
The video also touches on the differences in regenerative braking, noting that the quad motor felt slightly stronger in this aspect compared to the dual motor. Both drivetrain options have their pros and cons, with the dual motor being quieter and smoother for general use, while the quad motor offers a bit more excitement and speed on challenging back roads. The analysis concludes with insights into clutch disconnect mechanisms and their impact on efficiency and performance in various driving conditions.
00:50:00
In this segment of the video, the speaker discusses the development and fine-tuning of the vehicle’s dual and quad motor systems. They highlight the teamwork involved in smoothing out the design and performance of the chassis and software components. Key points include the dual motor’s superior noise performance and efficiency compared to the quad motor, and the ongoing challenges with the quad motor system, particularly around drive train concerns and differential locks. The speaker suggests opting for the dual motor system due to its refined design, quieter operation, and in-house integration. The segment transitions to a factory tour where the speaker showcases the production line, motor components, and the design and functionality of the drive unit, emphasizing how these elements are optimized for performance and efficiency in their vehicles.
01:00:00
In this part of the video, the speaker discusses the flexibility and efficiency of using silicone IGBT and silicon carbide MOSFETs in power modules, highlighting the efficiency differences between the two semiconductor devices. The primary focus is on the inverter chassis with custom-designed components such as capacitors and a gate driver card, which utilize press-fit connections instead of soldering. The inverter aims to minimize fasteners and harnesses, simplifying its assembly.
Furthermore, the segment details the mechanical and electrical design improvements, including the integration of a custom control card and current sensor without external harnesses. It also explains the operational mechanics behind the power flow from the inverter to the vehicle’s wheels, detailing the transformation of DC to AC power and the torque multiplication process through a two-stage gear reduction. Emphasis is placed on the integration of cooling systems into the drive unit for efficient thermal management. Finally, the explanation covers the differential assembly and its operational modes, including an electromagnetic coupling system for gear engagement and disengagement.
01:10:00
In this part of the video, the speaker addresses a question about battery preconditioning in motors and mentions the heat production per motor, which is roughly four kilowatts each. They discuss the thermal management systems of electric motors, highlighting differences between water-cooled inverters and oil-cooled rotors and stators. The conversation then shifts to comparing dual motor and quad motor systems, with a preference for dual motors for most users due to their quieter operation and nearly equal performance in everyday scenarios. The quad motor offers enhanced off-road capabilities but has limitations in thermal management and is louder. The recommendation favors the dual motor for 99% of use cases, suggesting that it is more practical and cost-effective for most drivers.