IHRA · Driveline

Aftermarket driveshaft and couplers

IHRA answers this part for 29 of its classes. 12 of those answers are permissions, with or without limits attached, and 17 are not. 12 are inferred from how the class is written rather than quoted from a rule naming this part.

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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, and where both govern you, you are held to the stricter of the two. The differences are set out in the rulebook comparison.

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.

OEM part required 5 classes

Must remain OEM.

• Drag, Sea-Doo vs Sea-Doo · DD.11
• Drag, Yamaha Pro Stock · DD.1
• Drag, Sea-Doo Pro Stock · DD.2
• Drag, Yamaha Spec · DD.3
• Drag, Sea-Doo Spec · DD.4

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 Lites
• Four-Stroke Ski Lites
• Runabout GP2
• Runabout GP3
• Ski GP2
• Ski Lites
• Ski GP3
• Ski Limited
• Drag, Turbo No Nitrous

Legal, within limits 1 class

Model-dependent. Aftermarket couplers and dampeners are permitted. W.5 Aftermarket permitted. · W.5

• Runabout Endurance

Legal, within limits 1 class

1:1 ratio. TITANIUM DRIVESHAFTS PROHIBITED. · U.5.2

• Sport Spec

Legal, within limits 1 class

1:1 drive ratio required. · CC.4.1

• Freestyle

Legal 4 classes

1:1 ratio.

• Runabout Limited · BB.9.4
• X2 Vintage · T.5.2
• Sport GP · V.8.2
• Runabout GP · X.6.3

Legal 2 classes

1:1 ratio required.

• Ski 1100 Modified · R.5.4
• Ski 1500 Modified · Q.5.4

Legal 1 class

1:1 ratio. TITANIUM DRIVESHAFTS ALLOWED in this class. · S.5.1

• Ski Vintage

Legal 1 class

Aftermarket permitted. · DD.5

• Drag, Super Stock

Legal 1 class

1:1 drive ratio required. · K.7.3

• Ski GP

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

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Aftermarket driveshaft and couplers: 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.