IHRA · Exhaust

Water-injected (wet) exhaust pipe, IHRA

IHRA decides this on how the pipe was manufactured and sold, not on how it is plumbed afterwards.

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This is one body's answer, not the sport's. You are bound by whichever body sanctions the event you enter. If you race more than one series, build to the stricter answer. The differences are set out in the rulebook comparison.

M.6.2.1.2 permits a purpose-built wet pipe on the 701 SuperJet and forbids converting a dry pipe into one. A product has to be a wet pipe as sold.

Where it stands, class by class

15 classes, grouped where the same rule gives the same answer rather than listed one by one, because an answer that holds for a class usually holds for every class that borrows its rules.

What each answer below means

Not permitted, not listed in the rules

Treat it as coming off. The class requires the craft to stay stock except where the rules allow otherwise, and this part is not on the list, so this is our reading rather than a rule we can quote at you.

Legal, with conditions

Keep it, but measure it: the rules permit this part only inside stated limits.

No rule, this is an open class

Probably keep it. The class carries no stock clause at all, so anything unlisted appears to be open. The rulebook does not say so in terms, and this is our reading rather than a permission anybody wrote down.

Not permitted, not listed in the rules 9 classes

On a closed list an unlisted modification is not permitted. · A.2.2, J.1

• Runabout GP2
• Runabout GP3
• Ski Lites
• Sport Spec
• Ski Limited
• Runabout Limited
• X2 Vintage
• Ski Vintage
• Sport GP

Not permitted, not listed in the rules 1 class

DD.7 states no engine type, so a two-stroke entry cannot be ruled out, and DD.7 does not list this part, so under the DD preamble it is not legal on either engine. · DD.7

• Drag, Turbo No Nitrous

Legal, with conditions 1 class

Only two machines may run one. The Kawasaki SX-R 800 may fit an aftermarket wet pipe (M.6.1.4). A two-stroke SuperJet on the 701 cylinder may fit a pipe manufactured, designed and sold as a wet pipe, never a converted dry pipe, with the CDI kept OEM (M.6.2.1.2). The 750 SX models, a SuperJet on the 760 cylinder and the four-stroke SuperJet keep the stock exhaust. · M.6.1.4, M.6.2.1.2

• Ski GP3

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

No rule, this is an open class 1 class

No restriction in section CC, and CC.1 permits any modification it does not restrict.

• Freestyle · CC

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What we corrected here, and when

• Ski GP3. Corrected 2026-10-02: this row said plain legal from the SX-R 800 clause alone. The class allows a wet pipe on two machines only, and the SuperJet one with conditions.

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Water-injected (wet) exhaust pipe: 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.

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