Cold Air Intake Kit — Install Guide

GT40 Marine | SKU GT40-SD-INT-CF | Carbon Fiber Cold Air Intake | Rev 1.0 — 2026-05-24

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Fitment

Not for: Spark, 130 / 155 / 170 HP NA models, pre-2016 1503 4-TEC. Confirm hull and engine code (1630 ACE) before install.

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In the Box

• (1) Carbon fiber filter housing
• (1) High-flow air filter element (pre-oiled)
• (1) GT40-machined intake adapter
• (1) Silicone coupler, 3.5" ID
• (2) T-bolt clamps, stainless 3.5"
• (1) Sensor harness extension (8 in.)
• (2) M6 × 20 mm SHCS mounting bolts
• (2) M6 nylon-insert lock nuts
• (1) Install hardware bag — spare washers + clamp
• (1) GT40 product registration card
• (1) This guide

Verify all components present before starting. Missing parts: support@gt40marine.com.

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Tools Required

• 8 mm / 10 mm / 13 mm sockets + ratchet, 3/8" drive
• T25 + T30 Torx drivers
• 5 mm hex (Allen) key
• 1/4" drive torque wrench, 5–25 Nm range
• Flat-blade and Phillips screwdrivers
• Trim removal tool (plastic pry)
• Shop towel + dielectric grease (small dab)

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Safety

Read in full before starting.

1. Battery disconnected for the duration of the install. Negative terminal off, secured away from the post.
2. Cold engine only. Supercharger housing and intake plenum hold heat after operation.
3. Eye protection when removing existing intake hardware — old hose clamps can spring free.
4. No smoking / open flame. Fuel-vapor recovery system is opened during install.
5. Marine-grade install only. This kit is designed for closed-cabin engine bay PWC use. Not for snowmobile or automotive application.

If you are not comfortable with PWC engine bay work, take the install to a certified Sea-Doo / BRP marine technician.

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Pre-Install Checklist

• [ ] Watercraft is on a stable trailer or stand, drain plugs removed, no fuel in lines from a prior burn
• [ ] Battery negative terminal disconnected and isolated
• [ ] Engine bay clean and dry — wipe down any oil or coolant residue near the intake side of the supercharger
• [ ] All factory torque values reviewed (see step-by-step torque table at end of guide)
• [ ] Photograph the stock airbox routing before disassembly (your reference for sensor + harness reconnect)

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Step-by-Step Install

Step 1 — Access the Engine Bay

Remove the seat. On RXP-X / RXT-X with rear storage, lift the storage bin to expose the engine compartment top hatch. On GTX models, the front service hatch must be opened separately.

Disconnect the battery negative terminal. Secure the cable away from the post.

Step 2 — Identify the Stock Intake Assembly

The factory intake on the 1630 ACE consists of:

• A black plastic airbox bolted to the engine bracket via three M6 fasteners
• A short rubber elbow connecting the airbox outlet to the supercharger inlet
• An IAT (intake air temperature) sensor threaded into the airbox shell
• The MAP (manifold absolute pressure) sensor harness routed across the top of the assembly

Photograph everything in this state. You will reconnect to the same sensors.

Step 3 — Remove the Stock Airbox

1. Unplug the IAT sensor — squeeze the plastic retainer, pull straight off
2. Unclip the MAP harness retainer from the airbox tab (do not unplug the MAP sensor itself)
3. Loosen the airbox-to-supercharger clamp using an 8 mm socket — back off until the rubber elbow is loose on the supercharger inlet
4. Remove the three M6 SHCS securing the airbox to the engine bracket (5 mm hex key)
5. Lift the airbox up and out. The rubber elbow comes with it. Set both aside.

Note: do not discard the stock airbox if you may sell the craft in stock form later. Store it.

Step 4 — Install the GT40 Intake Adapter

The GT40-machined adapter mounts to the same three threaded bosses on the engine bracket that held the stock airbox.

1. Position the adapter on the bracket with the inlet facing the rear of the engine bay
2. Hand-thread the two supplied M6 × 20 mm SHCS into the upper mounting holes
3. Snug both bolts evenly, then torque to 10 Nm (89 in-lb) with a 5 mm hex socket
4. Confirm the adapter outlet aligns squarely with the supercharger inlet — no side load on the silicone coupler

Step 5 — Connect Supercharger Inlet

1. Slide a T-bolt clamp onto each end of the supplied 3.5" silicone coupler
2. Push the coupler onto the supercharger inlet first — seat it fully against the inlet shoulder
3. Push the other end onto the GT40 adapter outlet
4. Orient both clamp heads to a position you can reach with a torque wrench (typically top-rear, away from the fuel rail)
5. Torque both T-bolt clamps to 5 Nm (44 in-lb) alternating until even
6. Pull-test the coupler — it should not move on either fitting

Step 6 — Transfer and Reconnect Sensors

1. Remove the IAT sensor from the discarded stock airbox using a 10 mm socket
2. Apply a thin dab of dielectric grease to the sensor threads — do not over-tighten
3. Thread the IAT sensor into the threaded boss on the GT40 adapter
4. Torque IAT to 8 Nm (71 in-lb)
5. Reconnect the IAT harness — listen for the retainer click
6. Reseat the MAP harness retainer onto the new adapter mounting tab. If routing is tight, use the supplied 8 in. harness extension

Step 7 — Install the Filter Housing

1. Slide the carbon fiber housing over the GT40 adapter neck
2. Tighten the housing clamp to 5 Nm (44 in-lb) — uniform draw, no clamp ear gap
3. Confirm housing clearance from chassis members: 10 mm minimum on all sides
4. Confirm the filter element is seated fully against the housing internal flange

Step 8 — Reassemble and First Start

1. Walk the engine bay — check every harness retainer, every clamp, every fastener torque
2. Confirm no tools, no rags, no removed hardware remaining in the bay
3. Reconnect the battery negative terminal — torque to 10 Nm (89 in-lb)
4. Replace the engine bay top hatch, storage bin, and seat
5. Start the engine on the trailer with the cooling hose connected
6. Idle for 60 seconds — listen for any intake leak (rush of air, lean stumble)
7. Scan with BUDS or compatible OBD diagnostic — confirm no new fault codes (P0102, P0107 indicate sensor reconnect issue)

If clean: install complete.

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Post-Install

Break-In

The filter element is pre-oiled. No break-in cycle required. The first 15 minutes of on-water operation may show a slightly richer idle as the ECU adapts trim — this is normal.

Tuning

This intake is plug-and-play with the factory ECU calibration. No tune is required for stock-engine fitment.

For Stage 2 and Stage 3 builds (with supporting fueling and exhaust upgrades), pair with the matching GT40 calibration on a Magic Module or equivalent platform. See GT40-SD-STG1-325 / GT40-SD-STG2-325 / GT40-SD-STG3-325 kit guides for full system tune notes.

Filter Service

• Inspect every 25 hours
• Clean per filter manufacturer guidance — solvent wash + re-oil
• Replace at 200 hours or sooner if visible damage to the element

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Troubleshooting

If symptoms persist after the checks above, contact GT40 Marine support before further operation.

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Torque Reference Summary

All torque values nominal — refer to current Sea-Doo factory service manual for any conflicting OEM specifications.

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Warranty

GT40 Marine warrants this kit free from defects in materials and workmanship for ninety (90) days from date of purchase. Warranty covers replacement of defective GT40-supplied components. Warranty does not cover:

• Damage from improper installation
• Damage from operation outside factory ECU calibration limits without supporting modifications
• Normal wear of consumable items (filter element)
• Damage from water ingress into the engine bay caused by hull breach, ride-plate failure, or operation outside design conditions
• Use on craft outside the listed fitment matrix

To submit a warranty claim: email support@gt40marine.com with order number, photographs of the installed kit, and a description of the failure mode. Response within two business days.

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Support

• Email: support@gt40marine.com
• Site: gt40marine.com
• Install help: include the GT40 SKU above and your hull serial number in any support correspondence

Built in the United States. Designed for buyers who want the best.

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This guide is © 2026 GT40 Marine. All rights reserved. Reproduction for personal install use is permitted. Commercial reproduction or redistribution requires written authorization.