Engine powered, so there is no motor KV: compare gearing by rollout.
Background
The MBX8 is a 1/8 four-wheel-drive buggy supplied as an assembly kit.1 The chassis uses straight-cut bevel gears and an enclosed receiver battery box.1 The instruction manual provides the assembly sequence and identifies the equipment the builder must supply.2 Gearing and equipment choices depend on the installed engine or motor and the track surface. The supplied chassis needs completion and setup before it can be driven.
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Check the kit's required-equipment list when selecting the parts needed to complete the vehicle.2
Pros
The kit manual documents assembly and component installation.2
Cons
The builder must supply the required radio and power equipment before running the vehicle.2
Specifications
Last modified
14 specifications across 5 groups, covering stock setup, dimensions and components.
Spec
Value
Basis
Vehicle
Class
The kind of vehicle the maker sells it as. It sets what the car is built to do and which cars it is fair to compare it with.
Buggies are low, light off-road cars built for jumps and fast corners on dirt, clay or turf tracks.
Drive
All four wheels are driven. That gives more grip under power, especially on loose ground.
The cost is more parts to maintain.
Power
A small two-stroke engine running glow fuel (methanol, nitromethane and oil).
It needs fuel, a glow igniter and some tuning.
It has no motor KV or battery rating.
Build
A kit you build yourself from parts.
Most kits come without motor, ESC, servo, radio and battery, and many without tires or a painted body.
The manual lists what to add.
Scale
The maker's nominal size compared with a full-size vehicle. It works more as a class label than a measurement.
A 1/10 monster truck is far bigger than a 1/10 touring car, so compare length and weight for real size.
Part number
The maker's product number for this exact version.
A V2, a new color, or a kit instead of an RTR usually has a different number, and parts can differ between them.
Check it against your box or receipt before ordering parts.
Class
Buggy
Drive
4WD
Power
Nitro
Build
Kit
Scale
1/8
Part number
E2021
Drivetrain
Pinion
On a nitro car the gear on the engine is the clutch bell.
Its teeth work like a pinion's: more teeth gear the car taller, for more top speed and slower acceleration.
Spur
The large gear the pinion drives. A bigger spur with the same pinion gears the car shorter.
Pinion and spur must have the same pitch, or tooth size, to mesh.
On a nitro car the clutch bell drives it.
Transmission & axle
Every reduction after the spur, multiplied together: transmission, differentials and axle gears.
It is fixed by the design; the gearing you change is the pinion and spur.
This one is worked out from the tooth counts the maker publishes.
Final drive
How many times the motor turns for one turn of the wheels. A higher number is shorter gearing: more acceleration and pulling power, less top speed.
Among 1/8 buggies in the catalog, the middle half run between 10.3:1 and 12.2:1 on stock gearing; this one is 12.2:1, shorter than most.
Pinion
Not published
Spur
Not published
Transmission & axle
3.38:1Derived
Derived
Final drive
12.24:1Stock
Stock
Wheels & tires
Tire diameter
The outside diameter of the mounted tire, tread to tread. A taller tire covers more ground each turn, which gears the car taller.
Race tires wear down over a day, and a smaller tire gears the car shorter.
Tire diameter
Not applicable
Power
Motor
An engine has no KV rating.
Nitro engines are sized by displacement in cubic inches, such as .21.
Battery
An engine car has no drive battery.
A small receiver pack or a BEC powers the radio and servos.
Motor
Not applicable
Battery
Not applicable
Performance
Theoretical top speed
An engine has no KV, so a theoretical top speed cannot be worked out from the gearing alone.
Theoretical top speed
Not applicable
How to read these figures
Stock is as the vehicle ships.
Calculated is worked from the stock figures on this page rather than stored beside them, so the two cannot drift apart.
Derived is worked out from gear tooth counts the maker publishes rather than printed as a ratio; the notes below say how.
Not applicable means the vehicle does not come with it, like the motor on a roller or the tires on a race kit.
Not published means it exists but no source we could find prints it.
