VehiclesArrma Infraction 223S BLX DSC

Arrma Infraction 223S BLX DSC

1/8 scale · street and speed-run body · ARA4315V4

Top speed: 50mphstock gearing
Speed set: 74mphincluded in the box
Final drive: 7.50:1
Tire: 85mm

Open in Top Speedverified

Arrma Infraction 223S BLX DSC — Photo: Horizon Hobby

Specifications

Last modified Sep 23, 2026

Spec	Value	Basis
Drivetrain
Pinion	19TStock	Stock
Spur	50TStock	Stock
Transmission & axle	2.85:1Stock	Stock
Spur ÷ pinion	2.632:1Calculated	Calculated
Final drive	7.50:1Stock	Stock
Speed gearing, in the box	28T / 50Tpinion / spurStock	Stock
Final drive, speed gearing	5.09:1Stock	Stock
Wheels & tires
Tire diameter	85mmEstimated	Estimated
Rollout	35.6mm per motor turnCalculated	Calculated
Power
Motor	3400KVStock	Stock
Motor shaft	5 mmStock	Stock
Battery	Up to 3SLiPoStock	Stock
Performance
Theoretical top speed, stock gearing	50.1mph on 3SCalculated	Calculated
Theoretical top speed, speed gearing	73.8mph on 3SCalculated	Calculated
Motor speed	37,740rpm, no loadCalculated	Calculated
Advertised top speed	65mphMaker's claim	Maker's claim
Vehicle
Part number	ARA4315V4
Scale	1/8
Class	Street and speed-run body

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. The top speed is kinematic: an ideal no-load RPM with no slip and no loss under load, so a real car is slower. Speed gearing is the taller set that ships in the box but is not fitted; swapping it in is the owner's job, and the car runs hotter on it. The maker advertises 65 mph, which is their own claim on their own conditions.

Gearing parts

Pinion and spur parts for the Arrma Infraction 223S BLX DSC: fitted, and optional gearing supplied in the box
Component	Teeth	Pitch	Bore	Part number
Fitted at the factory
Pinion	19T	Mod 0.8	5 mm	ARA311002 (opens in a new tab)
Spur	50T	Mod 0.8	Not applicable	ARA-2646 (opens in a new tab)
In the box, not fitted
Speed pinion	28T	Mod 0.8	5 mm	ARA311011 (opens in a new tab)

Tooth counts are the ones in the specifications above. Pitch is given as metric module (Mod 1, Mod 0.8) or diametral pitch (32P, 48P). They are different standards and are not interchangeable, even where the numbers look close. Bore is the pinion’s hole, listed separately from the motor shaft (5 mm on the stock motor). Gearing in the box is supplied, not fitted: the fitted set is what the figures and the calculators use. Linked part numbers go to the maker's or official distributor's page for that part.

How these numbers were settled

The 223S successor to the Infraction 4X4 3S BLX V3, now with a Spektrum Firma 3650 3400Kv motor and a Firma 100A Black Edition Smart ESC rated for 2S or 3S LiPo.

Horizon's spec table prints Pinion 19T, 28T, Spur 50T, Internal Gear Ratio 2.85 and Final Drive 7.50, and 50/19 x 2.85 = 7.50.
The 19T is fitted; the manual's kit overview lists an optional 28T speed pinion in the box (ARA311011, also on the standard-parts list), which gives 50/28 x 2.85 = 5.09.
The 65+ mph claim needs that pinion: stock gearing computes to about 50 mph at 3.7V per cell, the speed pinion to about 74 mph.
The tire diameter is worked out from Horizon's printed roll-out of 35.60mm per motor turn: 35.60 x 7.50 / pi = 85mm, which matches the 35mm-wide dBoots Hoons tread on a 2.4 wheel, but no tire page for this SKU prints it.

Documents

ManualInstruction manual (Horizon PDF) (opens in a new tab)Kit overview (optional 28T speed pinion)
Exploded viewExploded view (Horizon PDF) (opens in a new tab)
Exploded viewTechnical pack: pinion change, options, exploded view (Horizon PDF) (opens in a new tab)How to change the pinion/motor; Options

Sources

Every figure on this page traces to one of these. Where they disagreed, the note above says which was used and why.