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Class Legality

IHRA · sport

Sport GP

IHRA 2026, V. A closed-list class. The craft must stay stock except where the rules allow otherwise, so anything unlisted is not permitted.

  • 1Not legal
  • 2OEM part required
  • 12Not permitted, not listed in the rules
  • 42Legal, with conditions
  • 24Legal

Read out of the published IHRA rulebook on 2026-09-11, so confirm anything that decides a purchase. The full note is at the foot of the page.

Running the class

Eligible craft
Approved aftermarket hulls and modified OEM hulls, two-stroke and four-stroke. No model-year list is published.
Displacement limit
1300cc two-stroke, 1500cc naturally aspirated four-stroke and 1100cc forced-induction four-stroke (V.1). V.2.1 permits aftermarket pistons and boring as long as displacement does not exceed the class limits, so the figures are a ceiling on the engine as raced and not only as the factory built it.
Licence or tier
Expert or Pro recommended rather than required.
Minimum weight
Stated and unusable. See the uncertainty below.

Read from the same class section as the part answers. The rider side of the sport, tiers, ages, licences and what gets inspected, is set out across the bodies at Racing.

Open questions on this class (4)

Places where the rulebook contradicts itself, or where a figure could not be settled. Nothing in this list is decided, and it sits here rather than in a footnote because it is what you would want before spending money.

  • V.1 requires forced-induction four-strokes to weigh no less than 40 per cent of the original watercraft weight. As a minimum weight rule that is close to meaningless, since 40 per cent of stock is far lighter than any craft would be. It is almost certainly a transcription error and no weight check should be built from it.
  • V.5.2 permits the airflow sensor to be removed entirely. That allowance is unique to this class and sits oddly beside every other four-stroke class, which forbids modification downstream of the same sensor.
  • V.9.4 settles top deck appearance disputes with a silhouette test and does not describe the procedure.
  • V.7.1 prints "Electronic Contril Unit". A transcription defect.

Sections this rulebook does not contain for this class

Confirmed absent by a targeted read rather than merely unnoticed. In a closed-list class an absent article is why a part reads as not permitted; in an open class it is why one reads as open.

  • No published list of approved aftermarket hulls, which the section requires at V.9.1.

What the rules say (81 parts)

24 permitted outright, 42 permitted with stated conditions, 1 refused by a rule we can quote, 2 held to the original part by a rule we can quote and 12 refused by our reading of the class rather than by a quoted rule. Grouped where the same rule gives the same answer, so two "Not legal" groups can sit side by side under different rules.

What each answer below means

Not legal
This comes off. The rules refuse it in this class.
OEM part required
This comes off. Only the part the manufacturer fitted is allowed here.
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.
Legal
Keep it. The rules permit this part in this class.

Read the refusals as a list of work. Anything below marked Not legal, OEM part required, or Not permitted has to come off the machine, or go back to the standard part, before it races in this class.

Not legal1 part

Bolts, nuts and washers may not be substituted with titanium unless originally equipped. Locking mechanisms are allowed. J.7

OEM part required1 part

Must remain OEM. Four-stroke entries: Internal modifications allowed. V.4.5

Not permitted, not listed in the rules11 parts

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

Not permitted, not listed in the rules1 part

No clause lets in an aftermarket seat or seat base, so on the closed list it is not permitted. The OEM seat may take aftermarket covers and padding, and its height may be modified. V.9.3, A.2.2, J.1

Legal, with conditions1 part

Part of the exhaust system, which may be modified or replaced ("including head pipes and mufflers", V.2.5; "manifold, connecting pipes, hoses, muffler(s), etc.", V.4.4). Through-hull exhaust may be aftermarket if it creates no hazard, no tuned portion may protrude beyond the hull, and the exit may relocate to the transom below the bond flange. V.2.5, V.4.4

Legal, with conditions1 part

An aftermarket flame arrester is allowed if it meets USCG, UL-1111 or SAE J-1928 Marine standards. V.3.2, V.5.2

Legal, with conditions1 part

Four-stroke entries may modify, replace or remove the airflow sensor and may modify or replace the ducting between the flame arrester and the throttle body, provided performance and safety are not compromised. No cold air system is named. V.5.2

Legal, with conditions1 part

Four-stroke entries: May be modified, replaced with aftermarket, or completely removed. Unique to Sport GP four-stroke. V.5.2

Legal, with conditions1 part

On four-stroke entries the butterfly count must not exceed the cylinder count. V.5.3

Legal, with conditions1 part

Two-stroke: components must be unmodified and from another PWC; fully aftermarket allowed if meeting/exceeding OEM strength and safety. Original filler and relief valve must be used unmodified. Vapor/air separators max 2 in x 6 in with an always-open return line. ADDITIONAL FUEL RESERVOIRS PROHIBITED. Four-stroke (V.5.4): tank must be an unmodified OEM PWC part. V.3.3

Legal, with conditions1 part

SAE J30R9 on high-pressure. A.N. threaded or equivalent fittings with non-removable crimped clamps. Hose clamps and tie wraps NOT allowed. Metal filters only on high-pressure. V.3.1

Legal, with conditions1 part

Gauges may be modified or removed provided no hazard is created and any resulting hole is sealed. Section J permits modification and removal and never addresses adding an aftermarket instrument. J.15

Legal, with conditions1 part

Replacement wiring is allowed under J.7, and this class also opens the ignition system and electrical box to modification or aftermarket parts and allows an aftermarket ECU, so wiring inside the electrical box and serving the ignition and ECU may change with them. The harness beyond those parts is held to J.7 replacement. J.7, V.7.1, V.7.2

Legal, with conditions1 part

Four-stroke entries: Boost regulator mandatory. Water-jacketed housing required. Engines above 1100cc must remain naturally aspirated. Limits: max displacement 1100 cc, boost release psi under 900cc 12, boost release psi 901 to 1100cc 9. V.6.1

Legal, with conditions1 part

May be modified or replaced with an aftermarket part. The original diameter must be maintained in Stock class, and the rulebook never defines which classes that is. J.18.2

Legal, with conditions1 part

May be replaced within OEM specifications. J.18.3

Legal, with conditions1 part

Aftermarket or modified, full-length type with at least one bar parallel to the driveshaft, dropping no more than 12.00mm (0.47 in) below the flat plane of the pump intake. J.18.1

Legal, with conditions1 part

Aftermarket or modified. An extension may not exceed the width of the original plate, and on a ski may not extend more than 100 mm (3.94 in). J.18.1

Legal, with conditions1 part

Replacement trim plates may be used provided they mimic the handling characteristics of the stock plates. J.18.2

Legal, with conditions1 part

Braking devices may be disabled for safety, and reverse buckets and trim motors may be removed or modified to disable them, provided no hazard is created. J.18.4

Legal, with conditions1 part

Aftermarket hulls permitted with Race Committee and IHRA approval. V.9.1

Legal, with conditions1 part

Must be an exact replica of the original deck with no dimensional or scale changes. Minor angle and radii adjustments may be approved. Silhouette test settles appearance disputes (V.9.4). V.9.1

Legal, with conditions1 part

Must provide sufficient flotation. V.9.5

Legal, with conditions1 part

The storage covers and ventilation clause allows aftermarket covers and engine components that create no hazard and keep the OEM appearance, which on its heading reaches vent tubes and vent covers, though tubes are not named. V.9.6

Legal, with conditions1 part

Aftermarket, modified, repositioned or removed. Up to two, each no longer than 36 in (91.45 cm), protruding no more than 3.94 in (100 mm) horizontally, at least 6 mm thick with radiused leading edges, and not attached to a planing surface. J.16

Legal, with conditions1 part

Mat kits and padding are allowed in every class (J.14), and the Sport GP deck rule names foot holds as a legal aftermarket component that may be integrated into the deck. Foot straps are not named, so they stay not permitted. J.14, V.9.1

Legal, with conditions1 part

V.1 admits "Approved aftermarket hulls and modified OEM hulls" and names no craft type, so on any handle pole craft raced here J.17.2 lets the pole assembly and brackets be modified or replaced while keeping original functionality, with length alterable and the attaching point reinforceable.

Legal, with conditions1 part

Replacement bumpers and side rails may be used provided they create no hazard. A permanently affixed nose bumper remains required. J.13, I.17

Legal, with conditions1 part

May be added to adjust handling. Constant mass only, and no other part may be modified to carry it. J.19

Legal, with conditions1 part

Aftermarket cooling systems are permitted; four-strokes must point bypass fittings downward or rearward and use only fixed or automatic valves, and V.2.4 holds two-strokes to flow and operation regulations it does not spell out. V.2.4, V.4.3

Legal, with conditions1 part

Modified OEM hulls are eligible under V.1, within the class limits of 120 in maximum length and a width between 26 and 38 in. V.1

Legal, with conditions1 part

No Sport GP clause names a hull extension. V.1 admits a modified OEM hull, so an extension reads as hull modification inside the 120 in maximum length, and trim tabs stop 100 mm past the original planing surface. V.1, V.8.1

Legal1 part

The reed valve assembly may be modified or aftermarket, with no limit stated on petals, cage or spacers. V.3.5

Legal1 part

The intake manifold assembly may be modified or replaced with aftermarket parts, for two-strokes under V.3.1 and four-strokes under V.5.1. V.3.1, V.5.1

Legal1 part

The ignition system and electrical box that house a two-stroke CDI may be modified or replaced with aftermarket components, and V.7.1 also allows an aftermarket ignition system in place of the ECU. V.7.1, V.7.2

Legal1 part

V.7.2 opens the whole ignition system to modification or aftermarket parts, which takes in the trigger plate and timing, and the class states no timing limit. V.7.2

Legal1 part

The flywheel and flywheel cover may be modified or aftermarket, as may the ignition system and electrical box, and the battery charging circuit may be disabled or removed entirely. V.7.2, V.7.3

Legal1 part

Aftermarket pistons are permitted and the engine may be bored, provided displacement stays within the class limit, and two-strokes may change the number of piston rings. V.2.1, V.4.1

Legal1 part

Four-stroke entries: Camshaft count unchanged, original bearing type and dimensions, activation method unchanged. V.4.7

Legal1 part

May be replaced, as may starters and oil injection systems, with the oil injection system removable or disconnectable. J.8

Legal1 part

Intercoolers may be modified or replaced with aftermarket units, with no size or type limit, on the forced induction the class allows. V.6.2, V.6.1

Legal1 part

The hood may be modified or replaced with an aftermarket one, provided no hazard is created. V.9.2

Legal1 part

Aftermarket bulkheads are permitted, with no material or design limit stated. V.9.4

Legal1 part

Aftermarket seat covers and padding are allowed, and seat height may be modified. V.9.3

Legal1 part

Grips, throttle and cables may be modified or aftermarket. The bar must be padded at the mounting bracket or the crossbar padded. J.17.1

Legal1 part

Steering shaft, holder, handlebar holder and cables may be aftermarket, and quick-turn modifications are allowed. J.17.2

Legal1 part

The bilge pump may be modified or disconnected and aftermarket bilge draining systems are permitted, provided they create no hazard. J.10

IHRA 2026, V, read from the rulebook on 2026-09-11. Read the rule yourself. Every IHRA class · where the rulebooks differ · how this site reads a rulebook.

This is one class. Every part below also has a page of its own showing where it stands across every class this body runs, and legality by part is the index of them.

What we corrected here, and when

  • Aftermarket handle pole. Corrected 2026-10-07: the Sport GP row called the part not applicable to a seated class; V.1 states no craft type, and J.17.2 applies to every class.
  • Footholds, foot straps and tray mats. Corrected 2026-10-02: the Sport GP row read the closed-list default and refused a mat kit, which J.14, in the general rules for all classes, allows.
Cite this page

“Sport GP, IHRA class rules”, BaddJet archive, https://baddjetarchive.com/legality/ihra/sport-gp/

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81 parts read · 24 permitted, 42 with conditions · 2026 rulebook

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