How to Add Nitrous to Your Dodge Hellcat: Install Guide

Adding a nitrous kit to your Dodge Hellcat is one of the highest horsepower-per-dollar upgrades available for the 6.2L supercharged HEMI, and a supercharger-lid system makes the install genuinely bolt-on. The Nitrous Express kit featured here is adjustable from 100 to 400 extra horsepower on a single 10 lb bottle, fits 2015–2023 Challenger and Charger Hellcat and Demon models, and integrates cleanly with water-methanol injection. This step-by-step guide walks through how the system works, the tools and supporting parts you need, the full install, and the tuning and safety steps that keep 700-plus horsepower Mopars alive.

What a Supercharger-Lid Nitrous Kit Does on a Hellcat

A supercharger-lid nitrous kit replaces the factory plastic blower lid with a billet aluminum lid that carries integrated nitrous and water-methanol injection nozzles, spraying directly into the charge air above the rotors. Nitrous oxide (N2O) is roughly 36% oxygen by weight; when it decomposes near 570°F in the combustion process it releases that extra oxygen and simultaneously drops intake-charge temperature by a large margin, letting you burn more fuel and make more power. On a supercharged application the lid location matters: injecting into the lid distributes nitrous and methanol evenly to all eight cylinders and cools the entire supercharger discharge, which is exactly where a 2.4L or 2.7L IHI blower needs help.

Because this is a wet system, it delivers additional fuel along with the nitrous, so your air-fuel ratio stays in the safe 10.5–11.5:1 zone under the shot rather than leaning out. The Nitrous Express design is spraybar-less — there is no perforated bar to clog or shear — and the kit ships with a 10 lb bottle, billet lid, solenoids, jetting for 100–400 HP, and the plumbing to run it. Stock Hellcats already make 707–717 HP (797 HP on the Redeye, 808–840 HP on the Demon), so even a conservative 150-shot pushes a standard Hellcat past 850 wheel-capable horsepower.

Tools and Parts You Need Before You Start

Before spraying a single ounce, gather the supporting hardware and hand tools — a nitrous shot is only as safe as the fuel, charge-cooling, and drivetrain behind it. At minimum you need the nitrous kit, a set of spark plugs one to two heat ranges colder gapped to about 0.025 in, a way to add fuel (the wet kit handles this for smaller shots), and a plan for the extra torque hitting the rear wheels.

• Hand tools: metric socket set, torque wrench, T-handle Torx (T20–T40), pick set for O-rings, and a quality PTFE thread sealant for the nitrous fittings.
• Colder spark plugs: step one to two ranges colder and gap to roughly 0.025–0.028 in to prevent spark blow-out under nitrous.
• Charge cooling / detonation control: a water-methanol kit such as the Snow Performance boost cooler adds roughly 25 points of effective octane and drops intake temps.
• Airflow: a high-flow intake such as the K&N DRYFLOW keeps the blower fed at wide-open throttle.
• Driveline: upgraded half-shafts — the factory Hellcat axles are a known failure point once nitrous and sticky tires are involved.
• Safety: a wide-open-throttle switch and an RPM window switch so nitrous only flows at full throttle within a safe rev band.

How to Install the Nitrous Express Supercharger-Lid Kit

Installing the supercharger-lid kit takes a competent DIYer roughly 6–10 hours and centers on swapping the factory blower lid for the billet unit, then plumbing the bottle, solenoids, and activation wiring. Work on a cold engine, disconnect the battery, and depressurize any fuel line you open. The steps below follow the Nitrous Express instructions in the order we perform them on the lift.

Step 1: Remove the factory supercharger lid

Remove the engine cover, air intake, and throttle body, then unbolt the factory plastic supercharger lid. Keep the OEM gasket surface clean and cover the rotor pack so no hardware drops in. This is the moment to inspect the blower and confirm the 105mm throttle body bore that the kit and the water-meth plate both reference.

Step 2: Install the billet lid and nozzles

Transfer the sensors to the new billet lid, install the nitrous and water-methanol nozzles, and torque the lid to spec with a fresh gasket. Because the nozzles are integrated into the lid, there is no manifold drilling — the spraybar-less design meters nitrous through the solenoid and jet only.

Step 3: Mount the bottle and run the feed line

Mount the 10 lb bottle in the trunk with the valve angled toward the pickup (label facing forward, valve up at roughly 15 degrees), then route the braided feed line along the chassis away from exhaust heat. A bottle heater is worth adding to hold the ideal 900–950 psi bottle pressure that keeps the shot consistent.

Step 4: Wire the solenoids and safety switches

Wire the nitrous and fuel solenoids through a relay, then gate activation with a wide-open-throttle switch and an RPM window switch so nitrous can only flow above about 2,800–3,000 RPM at full throttle. Add a manual arming switch on the dash. This layered activation is the single most important safety measure on a forced-induction car.

Step 5: Jet conservatively, then tune

Start with the smallest jetting (a 100–150 shot), retard ignition timing about 1.5–2 degrees per 50 HP of nitrous, and datalog air-fuel and knock on the first pulls. Confirm the AFR stays near 11:1 under the shot and step up jet sizes only after clean logs. Never spray at low RPM, in low gears at part throttle, or with a bottle below roughly 850 psi.

Supporting Upgrades Your Hellcat Needs for Nitrous

Nitrous multiplies cylinder pressure and rear-wheel torque, so three supporting upgrades turn a risky shot into a reliable one: water-methanol injection to control detonation, a high-flow intake to feed the blower, and stronger axles to survive the hit. Below are the exact parts we install alongside the nitrous kit on Hellcat builds.

Water-Methanol Injection (Detonation Insurance)

A water-methanol kit is the cheapest detonation insurance you can buy for a sprayed Hellcat, adding around 25 points of effective octane while dropping intake-air temperature. The Snow Performance Stage 2 Boost Cooler references the 105mm throttle body, uses a boost-referenced controller, and shares the injection passages built into the Nitrous Express lid — so the water-meth and nitrous work together rather than fighting for real estate.

High-Flow Cold Air Intake (Feed the Blower)

A high-flow intake keeps the supercharger fed when the nitrous is calling for more air and fuel, and the K&N DRYFLOW system is a washable, oil-free filter that reuses for the life of the car. It fits 2017–2023 Charger and Challenger Hellcat 6.2L models (including Redeye, Demon, and widebody) and carries K&N's 10-year/million-mile limited warranty.

Level 5 Axles (Survive the Hit)

Factory Hellcat half-shafts are the first driveline part to break once you add a nitrous shot and traction, so upgraded axles are not optional on a sprayed car. The Driveshaft Shop Level 5 direct-fit axles are rated well beyond 1,000 HP, bolt in without modification, and fit 2015–2027 Charger and Challenger Hellcat and SRT models.

Nitrous Hellcat Parts Compared

Here is how the four parts in this build compare by role, headline spec, and price. The nitrous kit is the power-adder; the other three are the supporting upgrades that make the shot safe and repeatable.

Pros and Cons of a Hellcat Nitrous Kit