Not permitted, not listed in the rules 10 classes
On a closed list an unlisted modification is not permitted. · A.2.2, J.1
IHRA · Fuel
Aftermarket flame arrester
IHRA answers this part for 29 of its classes. 16 of those answers are permissions, with or without limits attached, and 13 are not. 13 are inferred from how the class is written rather than quoted from a rule naming this part.
Where it stands, class by class
29 classes, grouped by the answer rather than listed one by one, because an answer that holds for a class usually holds for every class that borrows its rules.
Not permitted, not listed in the rules Our reading, not a rule we can quote at you. This class requires the craft to stay stock except where the rules allow otherwise, and this part is not on the list.
No rule, this is an open class Our reading, not a rule we can quote at you. This class carries no stock clause at all, so anything unlisted appears to be open. The rulebook does not say so in terms.
Legal, within limits 2 classes
The intake manifold must remain as originally equipped, and a ribbon delete is permitted provided airflow is not increased.
- Runabout Lites · AA.3.1
- Runabout GP3 · Z.4.1
Legal, within limits 2 classes
Addressed with conditions.
- Ski 1100 Modified · R.3.1
- Ski 1500 Modified · Q.3.1
Legal, within limits 1 class
Nothing downstream of the airflow sensor may be modified, and neither may the turbo or supercharger system. · W.3.2
Legal, within limits 1 class
Intake manifold including screens and spark suppressors must remain stock. · N.3.1
Legal, within limits 1 class
No modifications downstream of the airflow sensor. INTAKE MANIFOLD MUST REMAIN AS ORIGINALLY EQUIPPED. Ribbon delete permitted if airflow is not increased. · Y.3.1
Legal, within limits 1 class
USCG, UL-1111, or SAE J-1928. No airflow changes beyond the sensor. · L.3.1
Legal, within limits 1 class
Airflow sensor and turbo/supercharger system must remain unmodified. · BB.4.1
Legal, within limits 1 class
USCG, UL-1111, or SAE J-1928 required. · CC.3.5
Legal 4 classes
Aftermarket permitted.
- Ski GP3 · M.2.2
- X2 Vintage · T.3.2
- Ski Vintage · S.3.2
- Sport GP · V.3.2
Legal 1 class
Intake silencers may be removed. Reed spacers may be added. · U.3.2
Legal 1 class
The air intake system may be modified or replaced. · X.3.2
No rule, this is an open class 3 classes
The class states only what it bans and calls itself run what you brung, against a section DD preamble that says anything unlisted is illegal.
- Drag, 2 Stroke Unlimited · DD.12
- Drag, Stand Up Unlimited · DD.10
- Drag, Unlimited · DD.6
Aftermarket flame arrester: if the rule your class applies reads differently to you, or the rulebook has changed since this was read, ask. We answer with the section we read it from, or that we have not read it. Ask a rules question.
Every IHRA class · where the rulebooks differ · signed checks on parts the shop sells.
Fuel · two and four stroke · legal outright in 16 of 29