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 · Hull and handling
Aftermarket seat cover
IHRA answers this part for 18 of its classes. 6 of those answers are permissions, with or without limits attached, and 12 are not. 12 are inferred from how the class is written rather than quoted from a rule naming this part.
Where it stands, class by class
18 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
Seat height may change by no more than 12.7 mm and the cover may be no thicker than 12.7 mm.
- Runabout Lites · AA.5.2
- Runabout GP3 · Z.10.2
Legal, within limits 2 classes
OE seat base must remain in use, with height change and cover thickness each limited to 12.7 mm. · U.6.1
Legal 1 class
Aftermarket permitted. · W.7.5.2
Legal 1 class
Seat height may be modified. · V.9.3
No rule, this is an open class 2 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, Unlimited · DD.6
Aftermarket seat cover: 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.
Hull and handling · two and four stroke · legal outright in 6 of 18