Introduction
Thank you for purchasing this Serpent RC car. You are now part of a large community of Serpent fans worldwide. This Serpent car is designed to provide many hours of racing excitement.
Serpent has been a leader in RC racing since 1980, developing numerous model cars. This extensive experience and knowledge are evident in their current vehicles.
The Serpent Cobra SRX8 RTR features state-of-the-art specifications and leads in 1/8 scale chassis design, incorporating years of racing knowledge from Serpent's designers. It continuously pushes performance boundaries.
The Serpent Cobra SRX8 RTR is an excellent entry point into RC racing, offering affordability and a solid foundation for a racing career. It is based on the high-end competition version of the Cobra SRX8, sharing its geometry and many parts, yet remains easy to use, maintain, and set up. The SRX8 RTR Cobra is fully upgradable to high-end competition specifications. Further details are available on the Serpent website.
Designed, tested, and raced by Billy Easton, USA. World Champion.
This manual provides essential steps for operating your Serpent car correctly. It includes a quick-start section, parts lists, exploded views, and setup guidance. A full assembly manual is available online at Serpent.com.
Please read this manual carefully before racing your car. This will ensure your safety, the safety of others, and allow you to enjoy your Serpent car for a long time.
Serpent is more than just the car; the company and its worldwide network of distributors and dealers are available to assist you.
The Serpent website, social media, and forum offer additional assistance and information.
Enjoy your Serpent, the racing experience!
Read This First
This is a highly technical hobby product intended for use in a safe racing environment. This car is capable of speeds exceeding 80 km/h (50 mph).
- Please follow these guidelines when building and operating this model.
- Parental guidance is required for builders/users under 16 years of age.
- Follow the building instructions. If in doubt, contact your dealer or importer.
- Use appropriate tools when assembling the car. Exercise caution with electric tools, knives, and other sharp objects.
- Be careful when using liquids like lubrication oil or glue; do not swallow. Follow manufacturer instructions if irritation occurs.
- When operating the car, stay clear of rotating parts such as wheels, gears, and the transmission.
- Avoid contact with hot parts immediately after use.
- Protective gloves are recommended.
- Operate the car only in safe environments, such as dedicated racing tracks or closed parking lots. Avoid public roads, crowded areas, or proximity to infants.
- Before operating, always check the car's mechanical status and ensure transmitter and receiver batteries are fully charged. After use, re-check all mechanics.
- Clean the car immediately after use and inspect parts for wear or fractures. Replace as necessary. Do not use water, methanol, thinner, or other solvents for cleaning.
- Store the car in a dry, heated place to prevent corrosion.
- Avoid operating in wet conditions, as water can cause corrosion on metal parts and bearings, leading to malfunction. If driven in wet conditions, ensure all electronic equipment is waterproofed and dry all moving parts immediately after use.
Safety Matters
All instructions in this manual must be followed to ensure safe use of the car. This model is not intended for use by children under 14 years.
Important Pre-cautions
- Only operate the car in designated areas or areas with very few people to prevent injury.
- The car has high power and rotating parts that can cause damage. Engine and motor parts can become very hot. Wear protective clothing as a driver and helper, and be careful when handling the car.
- Do not operate the car in dark conditions, as visibility is reduced, increasing the risk of accidents due to loss of control.
- Use good common sense while operating the car to ensure enjoyment and safety.
Battery and Battery-Charging
- The battery and battery charger are not included. The transmitter requires 4 AA NiMH batteries. The car requires a NiMH or LiPo battery with a capacity of 1600 mA or more.
- Use a battery charger specifically designed for the battery type and follow the supplier's and charger's instructions precisely.
- Always keep batteries and chargers in dry locations and never leave them unattended during charging.
- Dispose of batteries at the end of their life at a recycling facility. Check www.call2recycle.org for more information.
Quick-Start
This quick-start section is not a substitute for the full instructions. For optimal use, read the complete manual.
- Read the manual and safety pre-cautions.
- Purchase and install batteries in the transmitter (refer to the Transmitter manual). Install the receiver battery pack (not included) in the battery box and connect as shown in the manual.
- Turn on the transmitter (refer to the Transmitter manual). Always turn on the transmitter before switching on the car, and turn off the transmitter only after switching off the car.
- Fill the fuel tank with purpose-made model car fuel. Start and run in the engine as described in the separate engine manual.
- Check servo operation. Verify the servo functions correctly and that the car runs straight in neutral position; adjust trim as needed.
- Perform a range test with the radio system.
- Personalize your car's body by applying decals if desired.
- Drive your model car.
- Maintain your model car (refer to page 8).
Equipment
Included with Your Model
- Serpent model car, factory assembled and set-up.
- Dragon-RC transmitter.
- Serpent .21 high performance pull-start engine.
- Serpent .21 Inline Pipeset polished.
- Dragon-RC racing tires, pre-mounted.
- Dragon-RC digital servo.
Required for Your Model
- 4 x AA batteries for the transmitter.
- Receiver battery (NiMH / LiFe / LiPo).
- Fuel with 16% or 25% nitro and a fuel bottle.
- Glow plug starter.
- Tools: selection of Allen tools and screw-drivers.
- Hobby knife.
- Camber gauge.
Recommended Materials
- Side cutter and nose plier.
- Cleaning brush and towel.
- Safety glasses and gloves.
- Cleaning gum.
- Thin bearing oil.
- Transmission grease.
- CA glue.
- Degreaser.
Model Specs / Overview
This section provides a visual overview of the car's components. The diagram shows:
- Front Section: Steering block, Caster block, Front wishbone, Front camber link, Steering system, Shocktower front, Front body mount, Front shocks, Front driveshafts, Race-tyres.
- Central Components: Steering link, Steering servo, Speed controller, Receiver, Center diff, Chassis, Fuel tank, Exhaust, Clutch, Engine, Central rear driveshaft.
- Rear Section: Rear body mount, Rear upright, Rear camber link, Rear shocks, Shocktower rear, Rear anti-roll bar, Rear wing, Rear wishbone.
Diagram illustrating the layout and naming of key components on the Serpent Cobra SRX8 RTR.
Basic Tuning
Springs
Softer springs allow more suspension sag, chassis roll/lean, and dive, resulting in a less responsive car, which can be better on low-grip surfaces. Harder springs reduce sag, body lean, and dive, making the car more responsive. The choice depends on driving style and surface grip. Softer springs are generally more suitable for high-grip surfaces.
Shock-angle
The angle at which the shocks are mounted affects suspension feel. More vertical mounting makes the suspension feel harder, while more horizontal mounting makes it feel softer.
Oil
The viscosity of the shock oil determines the dampening effect. Thinner oil provides softer, slower damping, while thicker oil offers harder, faster damping. Damping can be further tuned by using optional pistons with different hole configurations.
Differential
The gear differential's hardness can be adjusted using different oil viscosities. Lighter oil creates a looser differential, increasing rear traction on acceleration but potentially causing more understeer. A harder differential reduces rear traction on acceleration but allows for more on-throttle steering.
Front Anti-roll Bar
A softer anti-roll bar increases suspension sag, chassis roll/lean, and dive, making the car less responsive but providing more steering once the corner is entered.
Rear Anti-roll Bar
A softer anti-roll bar increases sag, roll/lean, and dive, making the car less responsive. However, it enhances rear traction and stability.
Rear Toe Adjustment
Adjusted using suspension blocks (optional). More toe-in increases traction and stability but reduces speed. Less toe-in results in a less stable car with less traction but higher speed.
Front Toe Adjustment
Adjusted by lengthening or shortening the track rods. More toe-in provides more steering but less stability. Toe-out creates a more stable car with less steering.
Tuning (Continued)
Front Camber
Increasing negative camber in the front improves steering response but can also increase the possibility of traction roll.
Rear Camber
Increasing negative camber in the rear enhances grip, leading to more understeer.
Front Caster
Optional caster blocks can be used to adjust caster. Less caster reduces steering response and decreases the likelihood of traction roll.
Wheelbase Length
A longer wheelbase results in a more stable car that reacts slower. A shorter wheelbase makes the car more nervous and direct.
Wing Angle
The wing has two positions. Angling the wing more increases rear downforce, generating more traction and stability, but at the cost of speed. Conversely, a less angled wing reduces downforce.
Gear Ratio
For correct gear mesh between the spur and pinion gears, use a piece of notebook paper as a guide.
Ride-Height
Ride-height can be adjusted by applying more or less pre-load on the springs. Turn the pre-load adjusters to set the desired height, ensuring it is consistent on both left and right sides.
Maintenance
Shockabsorbers
Check for smooth operation and air bubbles by pushing the shock up and down rapidly after removing the spring. Clean shock absorbers as needed and refill with fresh 100% pure silicone oil.
Tyres
Replace tires if worn or damaged. Clean the tire surface if dirty to improve grip.
Wheel-axles and Driveshafts
Remove wheels and check wheel-axles, driveshafts, and adaptors for dirt, play, and pins. Clean thoroughly as needed and lubricate moving parts with a small amount of grease or oil.
Differentials
Check differentials and gears for wear and dirt, and clean as needed. Verify differential function by turning the wheels in opposite directions; it should feel smooth. If it feels gritty, the silicone oil may need replacement.
The full assembly manual for this model is available online. Visit www.serpent.com, enter your model number, part number, or select your car from the car page, then navigate to the download section to get the full manual.
Differential and Clutch Exploded View
This section details the components of the differential and clutch assembly.
Differential Parts: 601068 HTD diff set 44T fr/rr SRX8, 601069 HTD diff set 46T center SRX8. Other numbered parts include gears (601062, 600421, 601212, 600214), bearings (600562, 110502, 601067), diff cases (601205, 110211), and various screws and pins (e.g., 110115, 110127, 600627, 601060).
Clutch Parts: Clutch bells (600217 14T, 600218 15T, 600219 16T, 600220 17T), clutch springs (600578 1.0mm, 600579 1.1mm), clutch shoes (600883 alu 6061, 600884 alu 7075), and associated components (e.g., 6503, 600563, 110440, 600564, 600565, 600566, 110424, 600216, 110500, 110152).
Exploded view diagram of the differential and clutch assembly with part numbers.
Central Exploded View
This view shows the central chassis components and their assembly.
Main Chassis: 601211.
Drive Train Components: Center gear (601069), drive shafts (e.g., 600742), and associated mounting hardware (screws like 110146, 110105, nuts, washers like 600748, 600524, 601210, 601213).
Braking System: Brake plate mount set (600743), brake disks (600744), brake plates (600829). Other parts include brake adjust collars (600963, 600964).
Other Parts: Body mounts (600745, 600746), receiver box components, and various screws and pins (e.g., 110109, 110115).
Exploded view diagram of the central chassis and drivetrain components with part numbers.
Rear Exploded View
This section details the components of the rear suspension and drivetrain.
Rear Suspension Arms/Links: Antiroll bars (e.g., 600237, 600239, 600338, 600339, 600434, 600969, 600970, 600971, 600972), suspension brackets (600734, 600735, 600823), rear uprights (e.g., 600546, 600544), rear wishbones (e.g., 600553, 600545).
Rear Shocks/Shocktower: Shocktower rear (600847), rear shocks (e.g., 600554 REAR), springs (e.g., 600652, 600653, 600655, 600656, 600657), and associated hardware.
Rear Drivetrain: Rear driveshafts (e.g., 110502), hub carriers (e.g., 600641), and related pins and screws.
Other Parts: Rear wing mount (601066), transmission brace (600845), hingepins (600108), and various screws and fasteners.
Exploded view diagram of the rear suspension and drivetrain components with part numbers.
Front Exploded View
This section details the components of the front suspension and steering assembly.
Front Suspension Arms/Links: Antiroll bars (e.g., 600240, 600242, 600336, 600337, 600881, 600965, 600966, 600967, 600968), suspension brackets (600736, 600737), front uprights (e.g., 600183, 600223), front wishbones (e.g., 600326, 600554, 600539).
Front Shocks/Shocktower: Shocktower front (600846), front shocks (e.g., 600575 FRONT), springs (e.g., 600646, 600647, 600649, 600650, 600651), and associated hardware.
Front Drivetrain: Front driveshafts (e.g., 110502), hub carriers (e.g., 600481), and related pins and screws.
Other Parts: Transmission brace (600844), hingepins (600108), suspension bracket inserts (600823), and various screws and fasteners.
Exploded view diagram of the front suspension and drivetrain components with part numbers.
Steering Exploded View
This section details the components of the steering system.
Steering Servo Mounts and Linkages: Servo levers (600290, 600291, 600292), servo saver components (e.g., 600759, 600170, 600178, 601052, 601203, 601207), steering arms, and connecting rods.
Other Steering Parts: Various screws, nuts, and pins (e.g., 110102, 110184, 1321, 110105, 600729, 600754, 110104, 110110, 110511, 110402, 600227, 600178, 110439, 601203, 110125, 600750, 600167, 110102, 110159, 601206, 110127, 110401, 110101, 600764).
Exploded view diagram of the steering system components with part numbers.
Central Exploded View (Engine Mount)
This section details the central components including the engine mount and related parts.
Engine Mount: Enginemount low S811 RTR (600928).
Throttle/Brake Linkages: Servo levers for throttle (600841, 600842, 600843), brake adjust collars (600963, 600964).
Engine Components: Exhaust system parts (e.g., DRC 210021), engine mount screws (e.g., 600761, 804181, 600880, 110116, 110127, 600762, 600763, 600760, 110128, 110146, 1606, 110188, 600757, 110149, 110152, 110169, 600724, 110108, 110105).
Exploded view diagram of the engine mount and associated central components with part numbers.
Radio Exploded View
This section details the radio control system components and their placement.
Receiver and Related Parts: Receiver (600832), antenna tubes, and mounting hardware.
Suspension/Chassis Components: Shock absorbers (e.g., 600184), suspension arms (e.g., 110137, 600224), shock towers (e.g., 600767), and associated screws and pins (e.g., 600243, 600756, 600340, 110195, 600767, 1494, 110146, 600115, 600765, 110116, 600166, 600773, 130005, 130006, 130001).
Body/Wing Components: Wing parts (e.g., 600439, 600440, 600840), and body mounting hardware (e.g., 1601, 110157, DRC 214002, 600222, 600297).
Other Parts: Various screws, nuts, and clips (e.g., 110146, 600833, 600301, 600439, 600440, 600825, 600840).
Exploded view diagram of the radio control system and related chassis components with part numbers.
Shocks Exploded View
This section details the components of the shock absorbers.
Shock Body and Internals: Shock bodies (FRONT 600575, REAR 600576, FRONT 600393, REAR 600640), shock shafts (600180), pistons (e.g., 600234, 600235), seals, and O-rings.
Springs: Various front (FR) and rear (RR) springs are listed with their part numbers and load ratings (e.g., 600646 orange V2, 600647 red V2, 600649 blue V2, 600650 purple V2, 600651 green V2 for front; 600652 orange V2, 600653 red V2, 600655 blue V2, 600656 purple V2, 600657 green V2 for rear).
Spring Sets: Spring set FR V2 (600658), Spring set RR V2 (600659).
Other Parts: Top caps (600574), bottom caps (600573), shock collars (600111), shock mounts (600925, 600926), and associated hardware.
Exploded view diagram of the shock absorber components with part numbers and spring specifications.
Final Exploded View
This section shows the final assembly of the car, including the body and wheels.
Body: Body SRX8 (600718), Body SRX8 High Downforce (600719). Body mounting hardware (1601, 110157).
Wheels and Tires: Pre-mounted tires (DRC 214002), wheel nuts (600222, 600297 opt).
Exploded view diagram of the final car assembly, showing body and wheel placement with part numbers.
Team Serpent Network
Explore spare parts, optional parts, tools, and merchandise from Serpent.
- Cobra SRX8 RTR Spare Parts: www.serpent.com/600023/spares/
- Cobra SRX8 RTR Optionals Parts: www.serpent.com/600023/Optionals/
- Serpent Tools: www.serpent.com/product/Tools/
- Serpent Merchandising: www.serpent.com/product/Merchandising/
Serpent Website and Blog
Find more information and community resources:
- Website: www.serpent.com
- Team Serpent: www.teamserpent.com
- Dragon-RC: www.dragon-rc.com
- Promo Pages: http://promo.serpent.com
- Facebook Groups: www.facebook.com/serpentmrc
Serpent Social Media
- Facebook: www.facebook.com/SerpentMRC
- Twitter: www.twitter.com/SerpentMRC
