Noise and mufflers, as the rule books set them.

Noise is controlled by racing rules, not found in law

The research for this site looked for a regulator's noise or land-use rule specific to RC car tracks and found none. Every limit on this page is a governing body's rule, binding only at that body's events. The one statement about law that appears, in an EFRA appendix, could not be checked against any regulator's text and is given below as EFRA's claim.

EFRA: Appendix 8, 2026

EFRA's 2026 Appendix 8 covers mufflers for its internal-combustion classes:

• Every engine needs both. Each engine must have an exhaust system and an inlet silencer to reduce noise.
• Registered mufflers only. Only EFRA-registered mufflers may be used at sanctioned events: 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 on the muffler. EFRA explains that it now speaks of "registration" rather than homologation so that a listed muffler is not taken as always acceptable. A registration lasts two years.
• Outlets and silencer boxes. The muffler outlet pipe may be at most 8.00 mm across for 1/8 and 5.20 mm for 1/10, the inlet silencer box's dimensions may not be changed, and approved boxes are listed on EFRA's website.
• The noise trap. Sections use a "noise trap" on track, depending on the layout, to take out cars that make too much noise. The final noise limit for an event must be set before timed practice, and EFRA's definition of a noise level is final.

EFRA's General Rules (2024, rule 7.1.12) also list among referees' points of observation any car that breaks the noise rules because its silencer has been lost or damaged.

EFRA's statement about EU law

Appendix 8 states that the legal noise level within the European Community is 83 dB without the need for extra personal protection. That is a governing body's statement about law. No EU regulator's text was read to confirm it, so this site treats the figure as EFRA's claim, unconfirmed.

IFMAR: World Championship rules by class

IFMAR's rules differ by class, and each applies only at that class's World Championship.

• 1/8 IC track (2023, rule 5.7). Homologated mufflers of at least three chambers with a straight circular outlet, and homologated inlet noise silencer boxes, are mandatory. The maximum noise for a muffler with its silencer box is 85 dB, measured at 10 m distance and 1 m height. IFMAR's definition of noise is final, the outlet must point horizontally or downward, and mufflers may be cut open for checks.
• 1/10 IC track (2024). Homologated double-chamber mufflers with homologated silencer boxes. For homologation each muffler is tested on an engine at 40,000 rpm and may not exceed 85 dB at 10 m and 1 m height (rule 5.8). The tailpipe may be at most 5.20 mm across internally.
• 1/8 IC off-road (2024, rule 2.3). Only IFMAR-homologated silencers carrying their homologation number. Silencers may be homologated by ROAR, EFRA, FEMCA or FAMAR up to four months before the event, and IFMAR publishes its approved muffler list two months before.

The rules side by side

ROAR and the BRCA

ROAR's current rule book could not be read, so its muffler and noise rules are not recorded here. The BRCA's handbooks were not read either. One BRCA briefing was: at Large Scale Off-Road Round 8 (11 and 12 October 2025), random scrutineering included sound-level checks. The BRCA's large scale off-road national series runs cars with petrol engines of 23, 26, 30 or 32 cc, according to its 2026 section page; what noise limit applies in that series was not found.

What was looked for and not found

No regulator's noise limit or land-use rule touching RC car tracks was found, and the EU noise figure EFRA cites could not be traced to a regulator. Not found is not the same as not existing. Engine and muffler limits in full are on nitro engines and mufflers, and how bodies publish their lists of approved parts is on approved equipment lists.