Traxxas XRT Ultimate (Model 78097-4) Owner's Manual

Introduction

This manual provides essential instructions for operating and maintaining your Traxxas XRT Ultimate model, ensuring years of enjoyment. Traxxas models are designed for peak performance and satisfaction, backed by professional factory support. This manual is crucial for unlocking the full potential of your model and understanding safe operation and maintenance procedures. Even experienced RC enthusiasts should review this manual.

Before You Proceed: Carefully read and follow all instructions to prevent damage. Failure to do so may be considered abuse or neglect. Examine the model and manual thoroughly before use. Once the model has been run, it cannot be returned or exchanged.

Warnings, Helpful Hints, & Cross-References: Icons throughout the manual indicate important warnings (⚠️), helpful tips (?), and references to related topics (➡️).

Support: For questions, contact Traxxas Technical Support toll-free at 1-888-TRAXXAS (1-888-872-9927) daily from 8:30 AM to 9:00 PM Central Time. Assistance is also available at Traxxas.com/support or via email at support@Traxxas.com. Traxxas offers a full-service repair facility and replacement parts are available online or through local dealers.

Registering Your Model: Register your product within 10 days of purchase at Traxxas.com/register.

Quick Start: A dedicated Quick Start path is included to help you get your model running quickly. Refer to page 9 for these procedures. This guide is not a substitute for the full manual.

Why It's The Ultimate

The XRT Ultimate builds upon the XRT's 8s platform, combining X-Maxx strength with race truck handling. It features high-strength aluminum upgrades in key performance areas, all-new belted Gravix™ tires, and color-matched aluminum components for enhanced durability and aesthetics. The model is equipped with ultra-smooth GTX shocks and the TQi Radio System with the Traxxas Link Wireless Module, enabling real-time telemetry for tuning and versatility. It represents the pinnacle of XRT performance, incorporating nearly every factory option.

Key Features:

• Aluminum C-hubs and Steering Blocks
• Precision Steering Components
• Aluminum Rear Hub Carriers
• 2085X Metal Gear Servo
• Belted Gravix™ Tires on XRT Race Black Wheels
• GTX Aluminum Shocks with TiN shafts

FCC Compliance: This device complies with Part 15 of the FCC Rules for Class B digital devices, operating under specific conditions to prevent harmful interference.

Canada, Industry Canada (IC): This Class B digital apparatus complies with Canadian ICES-003 and RSS-210 standards.

Radio Frequency (RF) Exposure Statement: Equipment should be installed and operated with a minimum distance of 20 cm between the radiator and the user's body. Operation Frequency: 2414~2453 MHz. Maximum Radio Frequency Power: 9.7 dBm.

Company Information: Traxxas, 6250 Traxxas Way, McKinney, TX 75070. Phone: 972-549-3000. Toll-free: 1-888-TRAXXAS. Internet: Traxxas.com. Email: support@Traxxas.com.

Safety Precautions

General Safety: Always follow all instructions and precautions for safe operation. This model is not intended for use by children or minors under 18 years of age and requires advanced driver experience.

LiPo Battery Hazards (⚠️ FIRE HAZARD!):

• LiPo batteries require special care and handling due to fire/explosion risks.
• Always use LiPo-specific balance chargers and Traxxas iD chargers for Traxxas iD batteries. Never use NiMH or NiCad chargers.
• Do not charge LiPo batteries in series or parallel.
• Inspect batteries for damage before charging. Do not charge or use damaged batteries.
• Store and charge LiPo batteries in a cool, dry place, away from other batteries. Do not exceed 140°F (60°C) storage temperature.
• Do not disassemble LiPo batteries or attempt to build your own.
• Always confirm charger settings match battery specifications. Do not exceed recommended charge rates.
• Do not charge batteries with internal charge circuits or altered configurations.
• Prevent short circuits by ensuring exposed battery contacts do not touch.
• Charge/discharge batteries in a fire-retardant container on a non-flammable surface.
• Never charge batteries inside or while driving in an automobile.
• Always charge in a well-ventilated area, away from flammable materials.
• Disconnect batteries and unplug chargers when not in use.
• If a battery becomes hot, disconnect immediately. Allow batteries to cool before charging.
• Always unplug the battery from the ESC when the model is not in use or stored.
• Do not expose chargers to water or moisture.
• Do not modify battery plugs/connectors.
• Store batteries out of reach of children and pets; adult supervision is required.
• Use common sense at all times.

Driving Safety:

• Radio interference can cause loss of control; maintain a safety margin around the model.
• Motor, batteries, and ESC can become hot; avoid touching until cool.
• Do not drive on public roads or congested areas.
• Drive with a spotter.
• Do not operate at night or when visibility is impaired.
• Avoid driving too close to yourself or spectators.
• Never pick up the model by its tires or wheels. Keep hands clear of moving parts.
• Always disconnect batteries when not in use. Never store the vehicle with batteries installed.
• Use good common sense; avoid abusive driving.
• Periodically check wheel nuts and hardware for tightness.

Speed Control (ESC) Precautions:

• Disconnect batteries when not in use.
• Insulate exposed wiring.
• Turn the transmitter on before the ESC.
• Avoid touching hot ESC/motor components. Ensure adequate airflow.
• Use Traxxas High Current Connectors; do not change connectors.
• The ESC is not protected against reverse polarity voltage.
• Adhere to ESC limitations. Do not mix battery types/capacities.

Risk of Injury: Do not stand directly behind the XRT Ultimate during operation to avoid injury from thrown objects. Keep spectators and animals at a safe distance. Eye protection is recommended.

Tools, Supplies, and Required Equipment

Your model includes specialty metric tools. Additional items are available from your hobby dealer.

Supplied Tools: 2.5mm "T" wrench, 2.5mm "L" wrench, 2.0mm "L" wrench, 17mm wheel nut wrench.

Required Equipment:

• Two identical LiPo batteries with Traxxas iD® High-Current Connectors (minimum 5000mAh 11.1V 3-cell, recommended 6700mAh 14.8V 4-cell). Do not use NiMH batteries.
• A compatible LiPo battery charger (Traxxas EZ-Peak series recommended for safety and performance).
• 4 AA alkaline batteries for the transmitter.

Recommended Equipment: Safety glasses, Traxxas Ultra Premium Tire Glue (#6468), hobby knife, side cutters/needle nose pliers.

Anatomy of the XRT Ultimate

The XRT Ultimate features a complex assembly of components. Key parts include:

• Front Suspension: Upper Suspension Arm, Lower Suspension Arm, Steering Block, Caster Block (C-hub), Front Bumper, Front Shock Tower, Shock (Damper), Toe Link.
• Chassis & Drivetrain: Chassis, Spur Gear, Pinion Gear, Gear Cover, Electronic Speed Control, Receiver Box, LED Light Pipe.
• Rear Section: Wing, Rear Shock Tower.
• Power System: Motor with Cooling Fans, Battery Hold-Down, Battery Compartment, Traxxas High-Current Connector, Accessory Power Panel.
• Electronics: Steering Servo (under chassis), Receiver Access Plug.

Quick Start: Getting Up to Speed

Follow these steps to get your model running:

1. Read Safety Precautions (page 4).
2. Charge two LiPo battery packs (page 13).
3. Install 4 AA batteries in the transmitter (page 13).
4. Install charged battery packs in the model (page 14).
5. Turn on the radio system (page 15).
6. Check servo operation (page 16).
7. Range test the radio system (page 16).
8. Apply decals if desired (page 10).
9. Drive your model (page 21).
10. Maintain your model (page 26).

Note: The Quick Start Guide is a summary; read the full manual for complete instructions.

TQi Radio & Velineon Power System

Introduction: The XRT Ultimate is equipped with the Traxxas TQi 2.4GHz transmitter featuring Traxxas Link™ Model Memory. This system offers intuitive control and advanced tuning features like adjustable Exponential, End Points, and Sub-Trims for steering and throttle. The Multi-Function knob can be programmed for various functions.

Radio and Power System Terminology: Familiarize yourself with terms like 2.4GHz Spread Spectrum, BEC, Brushless Motor, Cogging, Current, ESC, Frequency Band, kV Rating, LiPo, mAh, Neutral Position, NiCad, NiMH, Receiver, Resistance, Rotor, Sensored, Sensorless, Servo, Transmitter, and Trim.

Key Terms Explained:

• 2.4GHz Spread Spectrum: Offers superior interference resistance and automatic frequency selection.
• BEC: Powers the receiver and servos from the main battery pack.
• Brushless Motor: High-performance motor using electronic commutation.
• ESC (Electronic Speed Control): Manages motor speed and provides features like Low-Voltage Detection.
• LiPo: Lithium Polymer batteries offering high energy density, requiring specific care.
• mAh: Measures battery capacity (run time).
• Thermal Shutdown Protection: Protects the ESC from overheating by limiting power.

Important Radio System Precautions: Do not kink or cut the antenna wire. Extend the antenna wire for maximum range, but protect it from damage. Ensure proper connections.

Model Wiring Diagram: Illustrates connections between the transmitter, receiver, servos, ESC, motor, and sensors (Voltage/Temp, RPM). The Velineon 1200XL motor specifications are provided (Type: Sensorless brushless, rpm/volt: 1200, etc.).

Transmitter Batteries: Uses 4 AA alkaline batteries. Use new batteries for optimal performance. Weak batteries can lead to loss of control.

Selecting Batteries: Requires two identical LiPo batteries with Traxxas iD® High-Current Connectors. Traxxas Power Cell LiPo iD® batteries are recommended. Do not use NiMH batteries with the VXL-8s ESC.

Selecting a Charger: Use a Traxxas EZ-Peak iD charger for safe and optimal charging of LiPo batteries.

Battery iD: Traxxas' feature that allows chargers to automatically recognize battery packs and optimize charging settings.

Body and Battery Installation: The model uses a clipless latching system for the body. Battery packs are secured by a hold-down mechanism. The Traxxas High-Current Connector ensures efficient power transfer.

Radio System Controls: Familiarize yourself with the transmitter layout: Steering Wheel, Throttle Trigger, Steering Trim, Multi-Function Knob, Set Button, Menu Button. Always turn the transmitter on first and off last.

Automatic Fail-Safe: The system returns the throttle to neutral and holds steering in the event of signal loss.

TSM (Traxxas Stability Management): Enhances control in low-traction conditions. Controlled by the Multi-Function knob. TSM is deactivated automatically in reverse.

Antenna Setup: Ensure the receiver antenna wire is properly routed and secured within the antenna tube.

Adjusting the Electronic Speed Control (ESC)

The VXL-8s ESC has factory default settings that are generally suitable for normal operation. Advanced settings can be customized.

Throttle Modes:

• Sport Mode (1 blink): Full forward, reverse, and brake.
• Race Mode (2 blinks): Forward and brake only (no reverse).
• Training Mode (3 blinks): 50% forward and reverse throttle, 100% brake, for easier control.

ESC Setup Programming (Calibration): If the ESC LED flashes green, recalibrate by following the steps to set the neutral throttle position.

VXL-8s Profile Selection: Profiles determine throttle/brake behavior:

• Profile #1 (Sport): 100% Forward, 100% Brakes, 100% Reverse.
• Profile #2 (Race): 100% Forward, 100% Brakes, No Reverse.
• Profile #3 (Training): 50% Forward, 100% Brakes, 50% Reverse.

LED Codes and Protection Modes: The ESC features protection modes indicated by LED lights:

• Solid Green: Power on, Low-Voltage Detection active.
• Current LED (A) Solid Red: Overcurrent Protection, Stage 1 (limits power to 50%). Check gearing.
• Current LED (A) Fast Blinking Red: Overcurrent Protection, Stage 2 (automatic shutdown). Remove obstruction.
• Voltage LED (V) Solid Red: Low Voltage Protection, Stage 1 (limits power to 50%). Stop driving.
• Voltage LED (V) Slow Blinking Red: Low Voltage Protection, Stage 2 (automatic shutdown). Stop driving.
• Voltage LED (V) Fast Blinking Red: Overvoltage Protection. Input voltage too high (exceeds ~33.6V). Stop driving.
• Temperature LED ( ) Solid Red: Thermal Shutdown Protection, Stage 1 (limits power to 50%). Check cooling fan.
• Temperature LED ( ) Fast Blinking Red: Thermal Shutdown, Stage 2 (automatic shutdown). Check cooling fan.
• Solid Red or All LEDs Fast Blinking Red: Critical error or simultaneous protection modes. Contact Traxxas Customer Service.

Driving Your Model

Where to Drive: Choose large, open areas away from pedestrians and traffic. Be considerate of property and avoid damage to landscapes. Confirm local ordinances permit RC vehicle operation.

Driving Conditions: Mixed surfaces are recommended. High load conditions (tall grass, deep sand) can cause overheating. Allow the model to cool between runs. Monitor temperatures to extend component life.

Low Battery Warning: Stop immediately if the model shows signs of low battery power (slow operation, delayed response, ESC shutdown). For the transmitter, a flashing red light indicates weak batteries.

General Driving Rules: Do not drive at night, on public streets, or in crowds. Do not run the motor if the model is stuck; remove the obstruction. Avoid driving directly toward yourself or others. Check hardware for tightness due to vibrations.

Run Time: Affected by battery type (mAh rating) and driving style. Higher mAh batteries provide longer run times. Aggressive acceleration and high speeds can decrease run times.

Tips for Increasing Run Time: Use high mAh batteries, a quality charger, follow maintenance instructions, keep the ESC cool, lower gear ratio, and maintain the drivetrain.

Running in Wet Conditions: The model has water-resistant electronics but is not submersible. Additional maintenance is required after wet use to prevent corrosion.

• Precautions: Not all batteries are wet-environment compatible. The Traxxas TQi transmitter is not water-resistant. Avoid rain and lightning storms. Do not use salt water or contaminated water.
• Before Running Wet: Consult "After Running" section. Cut small holes (3mm) in tires for water drainage. Ensure receiver box O-ring and cover are secure. Confirm battery compatibility. Use lower gearing in mud/puddles.
• Motor Precautions: Motor life can be reduced in mud/water. Use light throttle until excess water is expelled. Do not submerge the motor. Do not gear by temperature in wet conditions. Avoid mud buildup on the motor.
• After Running Wet: Drain tires by spinning at high speed. Remove batteries. Rinse with low-pressure water. Blow dry with compressed air (wear safety glasses). Spray bearings/drivetrain with water-displacing oil (WD-40®). Allow to dry.
• Receiver Box Maintenance: Ensure O-ring and cover are secure to maintain watertight seal. Periodically clean latches and mounts.

Basic Tuning Adjustments

Adjusting Gear Mesh: Proper gear mesh prevents stripped spur gears. A pin system helps set the motor position. Access by removing the motor and gear cover. Ensure pins are correctly placed for the chosen gearing. Manual adjustment using paper strips is also possible.

Centering Your Servo: If the servo horn is removed, re-center the servo before installation. Connect servo to Channel 1, ESC to Channel 2. Turn on the transmitter, turn off TSM, set steering trim to zero. Disconnect motor wires. Connect battery to ESC and turn it on; the servo will center. Install servo horn vertically. Check for equal steering throw and adjust trim if needed.

Fine Tuning the Shocks: GTX shocks influence handling. Periodic maintenance is recommended. Tune shocks in pairs (front/rear). Disassembly involves removing the cap screw, spring retainer, cartridge/shaft assembly, locknut, piston, and washer. Reassemble using pure silicone shock oil (30W front, 40W rear from factory). Adjust ride height by threading the spring retainer to keep suspension arms slightly above parallel.

Maintaining Your Model

Regular maintenance ensures optimal performance and longevity. Inspect for damage, binding, loose connections, and loose screws. Check radio system operation and battery condition.

Periodic Maintenance:

• Cush Drive: Inspect for play; disassemble and replace elastomer if needed.
• Chassis: Keep motor and ESC clean for optimal cooling.
• Suspension: Inspect for damage, bent pins, loose links, or stress.
• Steering: Check for looseness; replace worn toe links.
• Shocks: Maintain oil level; use pure silicone shock oil. Inspect for leaks and rebuild if necessary (rebuild kit #7762).
• Driveline: Inspect driveshafts and drive pins. Check spur gear for wear and set screw tightness.
• Torque-biasing center drive unit: Requires specific procedure and 20MM weight differential oil (#5040) for rebuilding.

Storage: Blow off debris. Always disconnect and remove batteries from the model and transmitter when storing.

Contact: For questions or technical assistance, call Traxxas at 1-888-TRAXXAS.

Suspension Module Removal/Installation: Detailed steps are provided for removing and reinstalling the front and rear suspension modules, including specific screw types (e.g., 3x15mm BCS, 4x25mm BCS). Ensure correct alignment and gear mesh during reassembly.

Advanced Tuning Adjustments

Roll Center: Adjusting roll center affects handling balance and stiffness. Raising the roll center increases stiffness. The default factory setup provides forgiving handling. Two positions are available: upper (lowers roll center) and bottom (raises roll center).

Gearing: Changing gear ratios (spur/pinion) affects speed and temperatures. Lower gear ratios (numerically higher) reduce current draw and heat. Higher gear ratios (numerically lower) increase top speed. Use the formula: (# Spur Gear Teeth / # Pinion Gear Teeth) x 8.11 = Final Gear Ratio. Monitor temperatures when using higher gear ratios.

Temperatures and Cooling: The model includes a motor temperature sensor, cooling fans, motor heat sink, and ESC cooling fan to manage heat.

Tuning Sealed Gear Differentials: Differentials can be tuned with different viscosity silicone oils. Higher viscosity oil acts like a limited-slip differential, distributing power more evenly, beneficial for low-traction surfaces. Factory fill: 10,000W front, 30,000W rear. Accessing differentials requires removing bumpers and differential covers. Refilling involves disassembling the differential case and adding oil.

TQi Advanced Tuning Guide

Traxxas Link App: Transforms your smartphone or tablet into a tuning tool via the Traxxas Link Wireless Module. Displays real-time telemetry (speed, RPM, temperature, voltage) and allows adjustment of Drive Effects like TSM, steering sensitivity, and throttle trim.

Pairing: Connect the transmitter and wireless module to your mobile device via Bluetooth through the Traxxas Link App. Follow on-screen prompts and LED indicators.

Tuning Adjustments via App/Transmitter:

• Steering Sensitivity (Exponential): Adjusts steering response. Negative exponential makes steering less sensitive near center.
• Throttle Sensitivity (Exponential): Adjusts throttle response for forward throttle only.
• Steering Percentage (Dual Rate): Controls the maximum steering throw.
• Steering and Throttle End Points: Set the maximum travel for steering and throttle/brake servos to prevent binding.
• Steering and Throttle Sub-Trim: Fine-tunes the servo's neutral position.
• Braking Percentage: Adjusts brake response (electric models).
• Throttle Trim: Adjusts throttle neutral position to prevent brake drag.

Setting Lock: Disables the Multi-Function knob to prevent accidental changes.

Traxxas Link Model Memory: Stores settings for up to 30 models (receivers). Automatically recalls settings when bound transmitter and receiver are powered on. Model Lock prevents deletion of stored models.

Menu Tree Navigation: The transmitter's MENU and SET buttons allow access to various functions and settings. Detailed diagrams illustrate navigation paths for adjustments like Servo Reversing, Sub-Trim, End Points, and TSM settings.