2021 Ram 1500 TRX Cold Air Intake Guide: Complete How-To

This 2021 Ram 1500 TRX cold air intake guide is built for owners who want measurable airflow gains without guessing which system fits their use case. The TRX ships with a 702 HP, 650 lb-ft supercharged 6.2L Hellcat V8, and that engine is hungry. Feeding it is the cheapest horsepower you will buy for the truck, and the restriction sits right in the factory airbox. In this how-to we walk through the install step-by-step, compare the four most popular aFe systems we sell at NLP Performance in Tampa FL, and answer the questions our customers ask most often.

Why Upgrade the TRX Air Intake?

The factory airbox on the 2021 Ram 1500 TRX is engineered for emissions compliance and noise control, not peak airflow. Third-party flow benches measure a 19% to 32% airflow improvement over stock depending on which aftermarket system you install, with the larger 3.5-inch tube Track Series and Momentum GT kits landing at the top of that range and the OEM-replacement Super Stock at the bottom.

Intake air temperature (IAT) drops of 10°F to 20°F are typical once the sealed airbox is pulling from the cowl or hood scoop instead of from around a hot supercharger. Cooler, denser air means the ECU can run slightly more aggressive timing before knock, which is where the dyno gains come from.

aFe publishes 19 to 29 HP and 17 to 25 lb-ft on their engineering dynos. Real-world third-party dyno runs we have seen on TRX builds typically land in the 19 to 23 HP range at the wheels — so the manufacturer numbers are honest on the low end, a little optimistic on the high end. The other gain most owners notice within ten seconds of the first start-up is the supercharger whine. A more open intake path amplifies that 2.4L IHI blower noticeably.

What You'll Need Before You Start

This is a 2 out of 5 difficulty job. Hand tools only, no specialty equipment, and no software. Budget 45 to 90 minutes depending on which system you picked and how thorough you are with routing.

• 8mm, 10mm, and 13mm sockets with a 1/4" and 3/8" ratchet
• Flathead and Phillips screwdrivers
• T-20 and T-25 Torx bits (for MAF sensor screws on some kits)
• Torque wrench capable of 30 to 90 in-lb for clamps and MAF hardware
• MAF sensor cleaner (CRC or equivalent) — never touch the hot-wire element
• Shop towels and a clean workspace for the MAF sensor
• 10mm wrench for the negative battery terminal
• Optional: nitrile gloves (Pro 5R oiled cotton filters transfer oil to everything)

Park on a level surface and let the engine cool for at least 30 minutes. The supercharger and intake manifold retain a lot of heat, and you will have your hands directly on the charge pipe area.

Step-by-Step Installation Guide

This sequence applies to the aFe Momentum GT and Magnum FORCE kits. Track Series adds a hood-scoop interface step, and Super Stock skips the airbox swap entirely and drops into the OEM housing. We will flag the differences as they come up.

1. Disconnect the negative battery terminal. Use a 10mm wrench, loosen the clamp, and tuck the cable aside so it cannot contact the post. This starts your ECU relearn clock and is non-negotiable. Leaving the battery connected risks a MAF fault code and a rough idle for the first 20 miles.
2. Remove the engine cover and factory airbox lid. Lift the decorative cover straight up off its ball studs. Release the two spring clips on the airbox lid, then unplug the MAF sensor harness by pressing the red lock tab back and squeezing the release.
3. Remove the MAF sensor carefully. Two T-20 Torx screws hold the MAF to the factory tube. Set the sensor on a clean towel, wire element facing up. Do not touch the hot-wire. If it is dirty, a single two-second pass with MAF-specific cleaner is all it needs — never brake cleaner, never carb cleaner.
4. Extract the factory intake tube and lower airbox. Loosen the throttle-body clamp (8mm hex), then lift the entire assembly out. The lower airbox sits on three rubber grommets — pull straight up. Save the grommets; the aFe kit reuses them.
5. Install the aFe airbox and tube. Seat the new airbox onto the factory grommets. Connect the silicone coupler to the throttle body, hand-tighten the worm clamp, and align the MAF bung on the new tube so the sensor sits at the same orientation as stock. Reinstall the MAF sensor with the supplied hardware and torque to spec (typically 15 to 20 in-lb — snug, not gorilla-tight).
6. Drop the filter in and seal the lid. Pro 5R or Pro Dry S installs with a single worm clamp onto the tube coupler. Check that the filter clears the airbox walls by at least 1/4" on all sides. Install the lid and snap the latches. For Track Series kits, this is where the carbon lid mates to the Anderson scoop or OEM hood channel.
7. Torque every clamp and re-plug the MAF. Do a physical walk-around. Tug each coupler, confirm the MAF connector is fully seated, and verify no tools, rags, or clamps are left in the engine bay. The MAF mount is the one fastener off-road vibration loves to loosen — double-check it.
8. Reconnect the battery and complete the ECU reset. Wait a full 10 to 15 minutes before reconnecting to let capacitors drain. Reconnect, turn the key to accessory for 30 seconds without starting, then fire the truck. Let it idle for three minutes, then drive a varied 20 to 30 mile loop (city and highway) to complete the ECU relearn.

If a check engine light appears and stays on after the relearn drive, pull the code. The two most common are P0171 (lean condition — usually a loose coupler) and P0101 (MAF range — usually contamination from an over-oiled filter or a loose MAF mount). Both are easy fixes.

The Best Cold Air Intakes for the 2021 Ram 1500 TRX

We carry every major aFe intake that fits the 6.2L supercharged TRX. Below are the five we recommend, in order of how often we install them in our Tampa shop. All pricing is current at NLP Performance.

Head-to-Head Comparison

Pros and Cons — Momentum GT Pro Dry S

Pro 5R vs. Pro Dry S — Which Filter Is Right?

This is the question our customers call about most often. Both filters are excellent. They target different priorities.

Pro 5R is a five-layer oiled cotton gauze filter. It flows more air at peak load than Pro Dry S, which matters at 5,500+ RPM pulls, and it is the right filter for track, drag, and tuned applications. Maintenance cadence is every 20,000 to 30,000 miles with the aFe cleaning/re-oiling kit. The catch: over-oiling is the single most common cause of post-install check engine lights on the TRX. The extra oil migrates downstream and coats the MAF hot-wire, which then reads lean. In our Tampa shop we see this almost every week on a Pro 5R that was re-oiled too generously.

Pro Dry S is a three-layer synthetic media filter that ships dry and stays dry. It flows slightly less at the ragged edge but eliminates the MAF contamination problem entirely. Maintenance is a simple vacuum or air-blow every 15,000 miles. For daily drivers, tow rigs, and anyone who forgets to re-oil, Pro Dry S is the safer choice.

Decision matrix: if your TRX sees tune work, track time, or drag strip duty, go Pro 5R. If it is a daily, a tow rig, or a garage-queen weekend truck, go Pro Dry S.

Complementary Upgrade — Anderson Composites Carbon Fiber Hood Scoop

The aFe Track Series intake is engineered to interface with an aftermarket hood scoop — specifically, a ram-air scoop like the Anderson Composites unit we stock. The sealed carbon lid has a channel that mates to the underside of the scoop, routing air directly from the leading edge of the hood into the filter box. At highway speed this creates a mild positive-pressure effect (roughly 0.3 to 0.5 psi above ambient at 70+ mph) and, more importantly, keeps the intake tract drawing from the coolest air available on the truck.

Without a matching scoop, the Track Series still works — it just draws from the same cowl area as the Momentum GT. If you are buying Track Series for the ram-air benefit, budget for the scoop too. The Anderson unit is pre-preg carbon, matte-finished on the underside, and mounts with 3M VHB plus mechanical fasteners.

Common Install Mistakes to Avoid

These are the five issues we troubleshoot most often on TRX cold air intake installs — all avoidable.

1. Over-oiling the Pro 5R filter. aFe ships the filter pre-oiled and ready to install. If you re-oil down the road, use the aFe squeeze-bottle kit and apply one bead per pleat, not a soaking. Excess oil migrates onto the MAF hot-wire and throws a P0101 within 500 miles.
2. Loose MAF sensor mount. The MAF screws into a bung on the new intake tube. Desert and off-road vibration will back them out. Torque to spec and consider blue Loctite on the threads.
3. Skipping the ECU reset. If you do not disconnect the battery for 10 to 15 minutes, the ECU holds its old fuel trims and the truck feels flat for the first hour. Worse, it can throw a false-lean code that takes a drive cycle to clear.
4. Ignoring silicone couplers. The couplers feel tight when cool and loosen slightly at operating temperature. Re-torque all clamps after your first 100 miles. This one catches everyone.
5. Wrong use case. Running an open-element Magnum FORCE in desert dust or deep water crossings is asking for trouble. Match the system to how you actually drive the truck.