The Hot Bodies Cyclone D4 is going to revolutionize the off-road racing scene! Combining intelligent & efficient design, a proven 4WD shaft drivetrain, and streamlined manufacturing processes, the Cyclone D4 is the result of months of non-stop testing and years of ambition!

Already a winner at its first major race, the IFMAR Worlds Warm-Up, the Cyclone D4 is destined to be the top choice for racers around the world in the increasingly popular 4WD off-road class!

The world wide HB racing team didn't want to stop with the World Championship winning Cyclone Touring Car. The D4 is the team's next step in making top level racing machines for a wide variety of racing classes. Every D4 driver will benefit from the racing experience of our world wide HB Off-Road Racing Team through the latest, top performance setup sheets and state of the art option parts development.

The HB website provides extensive set up sheets from the latest races and detailed build tips to get the best performance out of your D4 buggy.

The HB racing team will constantly develop the car and new options to stay on top of the competition. This means you will always have access to these developments and also stay on top of the competition with a future-proof platform.

Off-road racers will also be able to easily find spares and options - comprehensive parts lists, exploded views and the power of the world wide HPI/HB logistics system means that parts will be easy to find and supply will be constant and free of interruptions for D4 owners around the world.

Hot Bodies designers had an important decision to make before getting started on the off-road platform: what kind of drivetrain would be best? While the belt-drive Cyclone touring car is certainly the best on-road 4WD racer there is, the designers weren't sure a belt drivetrain could properly deal with the rigors of off-road racing.


Finally the decision was made for the shaft drive design for two main reasons:

1. The more direct response of a shaft drive system gives competitive Off Road racers the extra control they need. In Off-Road racing, throttle response on rough terrain or in the air is much more important for controlling the car than in an on-road environment.

2. Using a shaft drive train, meant our designers could ensure a sealed drivetrain that would be protected against the elements and be more reliable over bumps and through the ruts and therefore deliver a higher efficiency.

One word about torque steer: This is an issue in on-road cars with their narrower track, smaller tyres and shorter suspensions. In Off-Road cars, however, the mass of the tyres is much higher and the suspension is much wider. Therefore the force created by the rotating shafts is insignificant in relation. Bottom line torque steer is not an issue at all and the advantages of the shaft drive make it the superior system for Off-Road.

The foundation of the Cyclone D4 is its sturdy double-deck chassis. Made from woven graphite because of its low weight and high strength, the lower chassis is 2.5mm thick and the front and rear upper chassis pieces are each 2.5mm thick. Connecting the upper and lower chassis are the front and rear moulded composite gearboxes and the aluminium motor mount/middle bulkhead.

To make sure the chassis is extra-stiff and allows the suspension to do the work it's designed to do, the upper decks are held in place with a total of 11 flat head countersunk screws. The screws are arranged in a fully symmetrical pattern to minimise the effects of tweak on the suspension.

The lower chassis is as narrow as possible to place the weight as close to the center line of the car as possible. This improves the speed of weigh transfer for faster cornering.

Because of the clean layout there is enough room to easily fit any current electronics package, whether brushless or standard brushed system.
The motor fits into a large cooling cutout on the main chassis to allow it to get plenty of air, and to let it sit as low as possible in the chassis.

Fitting the batteries is very easy, too! The saddle pack style arrangement makes sure you get equal weight distribution and the moulded battery trays allow mounting the battery in two positions, all the way to the rear or slightly forward. This lets you tune the weight balance of the D4 for extra rear traction or more steering. Convenient straps hold the battery in place securely and allow you to quickly install and remove the batteries simply by removing body clips.

Keeping everything in place on the chassis are high quality Japanese-made hex head steel screws. The high grade steel resists breaking and the precision cutting ensures the screws tap the carbon plastic properly, letting you go through rebuilds without wearing the threads out.

All the screws feature a hex head which looks great and makes the car much easier to work on.
The standard steel ball ends are heavy duty and feature long threaded shafts to allow infinite adjustments with a selection on aluminium shims.
Cool purple anodized light weight shims are used throughout for camber link, bump steer and Ackermann adjustments.

From the one-piece aluminium front suspension bulkhead to the Infinite Roll Centre adjustments, you'll surely appreciate the effort that went into the suspension design of the D4.

In particular, the front end of an off-road racer has to deal with quite a lot - from pointing the car in the right direction, to powering the car through the middle of a tight turn, and even correcting the angle of the car in mid-air, there are many jobs it's entrusted to do, and it must do them all very well if the car is going to be a success! This is why Hot Bodies engineers spent as long as they could perfecting the design of the front suspension, to make sure everything was correct and is ready to go right out of the box for today's advanced racing drivers.

Our designers spent a long time getting the shocks in perfect order for high-level off-road racing.

The hard-anodized 7075 shock bodies are very tough, made from the strongest aluminium alloy used in RC today. Each shock body is also threaded for infinite ride height adjustment. The fine pitch of the thread allows you to make extremely small adjustments so you get the perfect ride height for any track you race on! Knurled shock collars allow you to get a good grip for easy adjustments and o-rings in the collars prevent any unwanted movement.

The top and bottom of each shock are enclosed with threaded aluminium caps. The top shock cap secures the mount in position, while the bottom shock cap contains a double o-ring shaft seal. Aluminium is used for the bottom cap for increased durability, lower maintenance and ease of rebuilding. However you prefer to fill your shocks, from the top or from the bottom these shocks can accommodate you! To prevent leakage both caps feature an o-ring seal.

For easy assembly the kit includes a set of tailor-made shock building tools for the top and bottom caps.





Each shock shaft is made from tough stainless steel, and feature threads at both ends - at the top to hold the shock pistons in place and at the bottom to attach the bottom shock mount.

For ultra fine tuning of the damping characteristics you get three different shock pistons with the kit. If this isn't enough for you there is also a set of blank pistons to drill your own piston holes!

Ride height limiters are included with the kit as well, allowing you to fine-tune the suspension to your exact driving style, track conditions and particular needs.

The D4 comes with HB black off-road springs as standard, which are the softer option of three different spring rates that are available for the car. Each spring is precisely tuned for off-road racing and features ground-flat ends, an all-black finish for stealthy good looks and identifying paint marks at one end.

In months of extensive track testing our HB race team and engineers have developed what we think is the finest off-road suspension geometry available today: wide track suspension arms, inverse steering block design, vertical ball end placement and of course full adjustability to name just a few highlights.

The front lower suspension arms are mounted to a one-piece aluminium bulkhead which directly bolts to the chassis.

The rear lower suspension arms are mounted to independently adjustable aluminium pivot blocks.

With the suspension components attached to the chassis independently of the gearboxes and other parts, you can be sure that the suspension does all the work of absorbing landings and keeping the tyres on the ground. No forces are transferred from the suspension to the drive train or vice versa.

All hinge pins are made from durable stainless steel and are held in place without e-clips, making removal of critical suspension parts easy and quick. Rubber bushings in the front bulkhead and rear pivot blocks hold the hinge pins in place and absorb shocks that might otherwise bend the pins or break other parts of the suspension.

Set screws hold the outer hinge pins in place, completing the 'No e-clip' suspension design and making the car overall easier to work on than other designs.

Front and rear wishbones feature a sleek aerodynamic design with integrated webbing to make them extra strong. The carbon-reinforced composite plastic makes them stiff and resists twisting. The V-shape design of the rear wishbones increases stiffness even further and allows the usage of longer stroke shocks.

The D4 steering blocks are a marvel of simplicity and design brilliance in their own right. The steering knuckles go around the uprights instead sitting inside a large C-hub as in a conventional design.
This "inverse" design allows the use of much more compact, simple, straight forward parts which makes the steering more precise and the construction more durable.

Providing the maximum amount of drivetrain efficiency while the suspension is compressed or when the front wheels are steering at extreme angles, Cyclone D4 engineers made sure that the steering kingpin and the universal joint line up exactly. This reduces stress on the universal joints and gives you increased driving feedback as you go through a turn.

The huge openings in the uprights for the driveshafts make sure nothing gets in the way of the shafts or the universal joints

The one-piece aluminium front suspension bulkhead features built-in 7.5 degrees of kick-up.

The rear anti-squat is adjustable with the two independent hinge pin pivot blocks. Placing aluminium shims under blocks varies the anti-squad angle to keep all the power on the ground.

Variable caster is provided by the 7 or 10 degree (both included) front caster blocks, and allows you to select the right amount for your driving style. More front caster generates more initial steering into the corner but less steering out of the corner.

Front toe is easily adjustable using the titanium steering turnbuckles.

Rear Toe in is set at three degrees at the pivot blocks as standard. It is also adjustable through the use of sturdy optional pivot blocks and/or rear hubs.

Using the Cyclone Infinite Roll Centre (IRC) adjustments, you'll be able to swiftly and conveniently control your roll centre front and rear. Long ball studs hold the camber ball links in place, and washers are used under the ball studs to raise or lower them as needed for each particular track.

The D4 features 2 inner and 1 outer camber link location at the front, and 1 inner and 2 outer locations for the rear.
The combination of adjustable inner and outer mounting points allows extra fine adjustments.





The wheel base can be adjusted simply by using shims on the outer rear hinge pin to change the position of the rear hub.

Four holes in the front shock tower and two holes in the suspension arm allow you a big range of possibly shock angles for easy tuning to any track. Both front and rear shock towers are made from ultra-stiff 3.3mm woven graphite for supreme stiffness and maximum strength!

The rear arms feature attachment points for a swaybar.
A firm silver sway bar comes as standard with the kit and an optional softer swaybar is available.

All the power that you can get from your Cyclone D4 won't mean a thing if you can't control it - which is why the D4's steering system is designed for ultimate control and response.

The heavy-duty steering system features a huge range of adjustments and standard features. The steering bellcranks are firmly attached between the upper and lower chassis pieces for solid control and rigidity. Riding on four ball bearings, the steering system allows you to experience full control and extreme precision. An adjustable servo saver is built-in to protect your steering servo from bad landings and rough crashes.
The steering servo is securely held in place with four screws directly on the lower chassis.



With the unique Cyclone Infinite Ackerman Steering (CIAS), you'll find that advanced steering tuning is easier than ever, giving you precise control over your cornering angles and power.

The steering rack uses thick, heavy-duty ball cups and titanium turnbuckles to connect to the steering arms.

You'll no doubt find that the D4 steering system is unique to off-road racers and features everything the expert-level racer requires for maximum control and racing accuracy.

All suspension and steering links are made of super light purple anodized titanium turnbuckles and heavy duty oversized ball cups. Together they form a strong and easy to adjust unit. The oversized ball cups ensure the turnbuckles have plenty of grip from the long threads and won't strip out or change the settings in crashes or heavy landings.

Finally, the precise ball cup shape provides smooth suspension action with a minimum of friction and play.

We've already gone over why HB designers chose shaft drive over belt, but now we'll get further into the details!

The centrepiece of the drivetrain is the aluminium middle bulkhead. It is a 3-piece design consisting of the front half including the motor mount, the rear half and an interlocking top brace, all made from slick, black anodized aluminium.


The motor shaft and centre driveshafts are perfectly parallel giving the D4 amazing drivetrain efficiency and low noise.


The aluminium top brace is held in place with four hex head screws allowing extremely easy slipper clutch adjustments and maintenance.

The tough spur gear is 48dp fine pitch for efficient power transfer. A wide range of optional pinion gears is available to fine tune the gear ratio.

The adjustable centre slipper clutch controls the application of power on low-traction off- road surfaces. Controlled and adjustable spinning of the slipper clutch instead of excessive wheel spin gives you more control and improved acceleration. The dual slipper pads are made from a proprietary long-life material for a consistent and smooth slipper action and long lifetime.

The whole slipper assembly sits on strong steel outdrives which spin the centre drive shafts.

The two front and rear centre drive shafts are made from extra-thick purple aluminium to keep the rotating mass low while maintaining strength.
In the slipper out drives steel pins are used for the dogbone end to increase durability and resist wear.

Going into the gearbox, universal joints connect the centre drive shaft to the internal bevel gears. Inside each gearbox, a pinion gear spins a ring gear attached to ball diff. The internal gears are also completely new and designed just for the D4!

The front and rear gearboxes and drive gears are a completely new design for the Cyclone D4 and are not re-used from any previous kit. Moulded from tough carbon composite plastic, each gearbox top and bottom features a tough structure of internal webbing to make them extra-strong to resist damage from crashes and big jumps.

The lower gearbox halves attach solidly to the main chassis and seal perfectly with the upper gearbox halves to provide a dirt-proof seal which protects the gears from any damage. The shock towers and upper decks connect to the upper gearbox halves, making them a strong and vital part of the chassis!

The gearboxes are not connected to the lower suspension arms at all, so they will not be affected by crashes or big jumps.

The ball diffs are interchangeable front and rear which keeps your spare parts count low, and feature carbide diff and thrust balls. This will give very smooth and consistent diff action which is essential for good cornering performance. The carbide material also increases the time between rebuilds.

Strong steel outdrives can handle all the power of a low-turn modified motors!

The diffs are also externally adjustable by simply popping off a camber link and using a hex wrench.

Getting the power from the diffs to each wheel are state of the art steel universal dogbones and axles, featuring the Hot Bodies logo laser-etched on each dogbone! Once again, steel pins are used for the dogbone end to resist wear.

Everything spins on 22 precision ball bearings for the best drivetrain efficiency and no loss of power!

The ball bearings are efficiently placed, with large diameter bearings on the slipper clutch and each diff, and small diameter bearings at each corner for less unsprung weight.

With the multitude of off-road wheels available now, Hot Bodies designers knew that making the D4 able to fit a variety of the most popular wheels would help make it a popular choice for experienced racers.
That is why the D4 features 12mm hexes at the front and rear to not only take the new D4 dish wheels but also a wide range of 3rd party rims.

The front hexes are made from steel and are extra thin with the pin sitting on the outside of the hex preventing the hex and pin from falling off without a wheel attached.

The rear hexes made from aluminium and are clamp-style which again holds the hex precisely and securely in place.

The use of aluminium hexes instead of a simple pin allows you to fully tighten the wheel nuts without fear of binding or crushing the bearings. This guarantees a free-spinning drivetrain. You'll also notice that your wheels will last longer!

The HB dish wheels are a one-piece solid design with an aerodynamic shape for increased strength and less chance of getting dirt stuck in the wheels. With a 2.2-inch standard size, any 4WD front and 2WD/4WD rear tyres will fit.

No tyres are included so you can choose the ideal tyres for your local track. So you don't have to pay extra for something you don't want or need.

For the front smaller 10mm hexes to fit Losi wheels are available as options parts.

At the rear Losi and Associated wheels will fit by simply removing the hex hub - just right for the 2WD racer who wants to give 4WD a try but doesn't want to buy a selection of new rear tyres!

Going the other way, you'll be able to also fit HB rear wheels to any Losi or Associated 2WD buggy by simply adding the clamp-on hex hubs.

The bodyshell of the D4 features a sleek yet high-downforce shape that is designed to maximise aerodynamic efficiency for performance and speed. The ultra-narrow chassis shape is enhanced by the form-fitting bodyshell that fits snugly around the lower chassis.

The narrow cockpit shape lets as much air as possible flow to the rear of the bodyshell, as it goes over the high-angle spoiler just before the rear shock tower and wing.


Durable wing mounts hold the wide rear wing in place high above the body, and also help prevent damage to the shock tower in rollover crashes. A front wing is included that attaches to the front shock tower for those times you need some extra front end grip.


Protecting the bottom of the woven graphite chassis is a polycarbonate undertray which fits perfectly inside the Cyclone D4 bodyshell. The undertray slots into the front bumper and then uses a unique cam attachment to hold securely onto the main chassis. No tape needed, so no fuss!

Keeping your electronics clean and free of any moisture is definitely an important consideration in off-road racing these days, and HB designers found that this was the best way to do it!




For those hot days of summer racing when the temperatures rise, the front cooling ducts can be opened up to allow fresh air to circulate over the motor, speedo and batteries. To let extra air out, the vents directly over the batteries can be cut out to release hot air.

The Cyclone D4. World-class performance and design in a world-beating package.

Length: 365mm
Width: 247mm front, 250mm rear
Wheelbase: 280mm ± 2mm (adjustable)
Weight: Bare Chassis approx. 1700g, running weight varies with equipment used
Chassis: Woven Graphite; 3mm thick main chassis & 2.5mm thick top decks
Suspension: Four-Wheel Independent, 14.5 to 17.5 degree front kick-up, variable anti-squat
Turnbuckles: Fully equipped, purple titanium with extra-long ball cups
Drive Train: Shaft 4WD, fully enclosed, Front & Rear Ball Diffs
Drive Ratio: 2.4375 to 1
Tyre Type: none included
Gear Pitch: 48 Pitch
Wheel Size: 2.2 inch diameter Front & Rear
Wheel Hubs: 12mm hex w/ capture pins; optional Losi front wheel fitting with included wheel hubs, can fit B4 rear wheels
Kit/RTR: Self-Build Kit
Shock Type: Hard-anodized, threaded bodies w/ top/bottom threaded seals
Shock Towers: Woven Graphite; 3.3mm thick Front & Rear Shock Towers
Bodyshell: Clear Polycarbonate with Wing and Undertray
Ball Bearings: Complete, 22 bearings in drivetrain

The Cyclone D4. World-class performance and design in a world-beating package.

Specification may be subject to change