Nitro gear: the class sets the engine, the muffler list sets the exhaust.

The class sets the engine

IFMAR's IC section writes a World Championship rule book for each nitro class, and each limits the engine. EFRA's IC engine appendices, ROAR's current rule book and the BRCA's 2026 section rules were not read for this site, so their engine limits are not given.

All three of the 1/8 and 1/10 books read impound cars at the end of the finals for inspection of engine size and fuel tank capacity. The cars must also be able to stand still with the engine running: IFMAR's 1/8 IC off-road rules (2.2) require brakes and a clutch that hold the car stationary, and its 1/10 IC track rules require a de-clutching device and a brake. Large-scale petrol classes have limits of their own: the BRCA's Large Scale Off Road series (2026) runs petrol engines of 23, 26, 30 or 32 cc.

Mufflers and noise

• IFMAR 1/8 IC track (2023, 5.7): homologated mufflers of at least three chambers and homologated inlet noise silencer (INS) boxes are mandatory; the maximum for a muffler with its INS box is 85 dB at 10 m and 1 m height.
• IFMAR 1/10 IC track (2024): homologated double-chamber mufflers with homologated INS boxes, each tested for homologation at 40,000 rpm and not to exceed 85 dB at 10 m.
• IFMAR 1/8 IC off-road (2024, 2.3): only IFMAR-homologated silencers carrying their number; ROAR, EFRA, FEMCA or FAMAR may homologate one up to four months before the event.
• EFRA (Handbook 2026, Appendix 8): only EFRA-registered mufflers, at least three chambers for 1/8 IC track, 1/8 off-road and GT8 and two chambers for 1/10 IC track, with the registration number engraved; sections use a "Noise Trap" at events and set the noise limit before timed practice. EFRA says it now speaks of registration rather than homologation so that a listed muffler is not taken as always acceptable.

EFRA's Appendix 8 also states that the legal noise level in the European Community is 83 dB without extra personal protection; the EU legislation behind that was not read, so it is EFRA's statement only. At EFRA IC events a plastic or wooden baton is mandatory at marshal positions as an aid to stop a running engine (General Rules 2024, 8.15). More on noise and mufflers.

The fuel, in brief

Fuel is not a pick here, and this guide gives no mixing or handling content. IFMAR allows only methanol and/or ethanol, oil, a little anti-corrosion additive and at most 25 percent nitromethane by volume in 1/8 IC track (2023) and off-road (2024), and 16 percent in 1/10 IC track (2024) and 1/8 GT (2025), and bans named additives. In the EU, Estonia's ministry says Regulation (EU) 2019/1148 restricts nitromethane above 16 percent by weight for the general public from 1 February 2021; a Red RC report of 5 October 2023 describes a cut to 12 percent, a figure not found in any regulator's text. Both are unconfirmed against the regulation's annex. Detail: nitro fuel rules.

On the hazard, NIOSH classes methanol as a Class IB flammable liquid and lists visual disturbance and optic nerve damage among its effects, with symptoms that can be delayed 1 to 72 hours; it classes nitromethane as Class IC. The HSE's technical report of March 2026 concludes that nitromethane meets the criteria for Acute Toxicity 4, STOT RE 2, Carcinogenicity 1B and Reproductive Toxicity 1B, in line with the opinion of the ECHA's Committee for Risk Assessment, but says that classification had not yet been agreed or adopted in Great Britain. See fuel hazards.

Starters

Starters are a category of nitro pit gear. The research behind this site recorded no rule about them, and this site has no product category for them, so there is no pick. They are named here so the list is complete; no starting procedure is given.

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