NC Miata Supercharger Install Guide: KraftWerks (06-15)

Adding an NC Miata supercharger is the single fastest way to wake up the 2006–2015 Mazda MX-5. The KraftWerks 06-13 Mazda Miata NC 2.0L Supercharger Kit bolts an intercooled Rotrex C30-84 onto the 2.0L MZR engine and delivers a KraftWerks-rated +110 wheel horsepower at 10 psi on 91-octane pump gas — roughly doubling what a stock NC puts down. It is a true bolt-on with no cutting, drilling, or welding, and it ships complete with a front-mount intercooler, header, and exhaust. This guide walks through exactly what the kit is, how much power to expect, the tools and supporting parts you need, and a step-by-step overview of the install — from our shop bench in Tampa, FL.

What Is the KraftWerks NC Miata Supercharger Kit?

The KraftWerks NC Miata supercharger is a complete, intercooled forced-induction system built around the Rotrex C30-84 centrifugal supercharger — the same family of blower used in KraftWerks' proven 2006-2013 Honda Civic Si system, resized to suit the Miata's 2.0L MZR (LF-VE) engine. Unlike a positive-displacement (roots or twin-screw) blower that delivers a wall of low-end torque, a centrifugal supercharger spins up with engine speed, so boost and power build progressively all the way to the NC's 7,000–7,200 rpm redline. The result is a smooth, factory-like power curve without the spiking or surging associated with turbochargers.

Rotrex units are prized for their compact size, high adiabatic efficiency, low vibration, and quiet operation. Their traction-drive technology transmits power through frictional forces between rolling elements and spins the impeller in excess of 200,000 rpm. Each Rotrex runs a self-contained oiling system independent of the engine, with a dual-action oil pump and a dedicated fluid cooler to keep temperatures in check. Because it runs cooler than a comparable turbo setup, intake air temperatures and detonation risk both drop.

How Much Horsepower Does It Add?

KraftWerks reports a +110 wheel-horsepower gain at 10 psi of boost on 91-octane pump gas, using the OEM-style header and exhaust included in the kit. A factory NC Miata puts down roughly 130–145 whp depending on year and transmission, so the supercharger pushes output to approximately 240–250 whp — a near-100% increase over stock. For context, the 2.0L MZR made 158–170 crank horsepower and 140 lb-ft from the factory across the NC1 (2006–2008), NC2 (2009–2012), and NC3 (2013–2015) generations, with the redline rising from 6,700 rpm on early cars to 7,200 rpm after the 2009 refresh.

The character of that power matters as much as the peak number. Because the Rotrex is a centrifugal supercharger, torque climbs with rpm rather than slamming in at 2,500 rpm. On the street that translates to instant throttle response, a linear pull, and none of the turbo lag or torque spikes that upset a lightweight, short-wheelbase roadster mid-corner. The progressive curve also keeps cylinder pressures reasonable, which is a big part of why the stock 2.0L bottom end tolerates this power level so well when tuned correctly.

Parts and Tools You Need Before You Start

The KraftWerks kit is comprehensive: it includes the Rotrex C30-84, a large front-mount intercooler, all aluminum charge tubing, silicone couplers, clamps, mounting hardware, and a header and exhaust. You will not need a separate cat-back — the kit supplies its own exhaust path. What the kit does not include is a tune or the supporting hardware a boosted Miata should have. Below is the supporting build list we recommend pairing with the supercharger so the car is safe, cool, and able to put the power down.

On the tool side, you will want a full metric socket and wrench set, torque wrench, jack and stands, a serpentine belt tool, a coolant drain pan (the intercooler piping and header work both benefit from draining coolant), and basic trim tools for the front bumper. A second set of hands makes routing the intercooler and charge piping far easier.

Step-by-Step: Installing the NC Miata Supercharger

Because KraftWerks engineered this as a bolt-on, there is no fabrication — but it is still a full-day job. Plan on 8 to 12 hours for a careful driveway install, or a weekend if it is your first forced-induction build. Always work on a cold engine and disconnect the battery before you begin.

1. Prep and remove the front end

Disconnect the battery, drain the coolant, and remove the front bumper cover and any belly pan or ducting. This exposes the front of the engine bay for the intercooler and gives you room to work on the accessory belt system.

2. Fit the header and exhaust

Remove the factory exhaust manifold and install the included header, then hang the supplied exhaust. Doing the exhaust first, while the engine bay is open, saves you from fighting for clearance later once the charge piping is in place.

3. Mount the supercharger bracket and Rotrex

Install the KraftWerks bracket that positions the Rotrex C30-84, then bolt the supercharger to it. Route the new serpentine belt per the instructions — correct belt tension is critical to prevent slip under boost.

4. Install the front-mount intercooler and charge piping

Mount the front-mount intercooler behind the bumper support, then connect the aluminum charge tubes and silicone couplers from the supercharger discharge, through the intercooler, to the throttle body. Snug every clamp — a blown coupler under boost is the most common first-drive failure.

5. Prime the Rotrex oiling system and fuel upgrades

Fill the Rotrex self-contained oiling system with the specified traction fluid and mount its cooler. If you are installing larger injectors, do it now while the intake side is apart. Double-check every fuel and vacuum connection.

6. Reassemble, refill, and tune

Refill the coolant, reinstall the bumper, reconnect the battery, and leak-check the entire charge path. The car must then be tuned before you drive it in anger — see the next section.

Why the "No Tune" Version Still Needs a Tune

This kit ships as a No Tune system, which means you must have the ECU calibrated for boost before the car is safe to drive. Bolting on a supercharger dramatically increases airflow; without a matching fuel and ignition tune, the engine will run dangerously lean under boost and risk detonation. A proper tune — done on a dyno or via a reputable NC Miata calibration — sets the air/fuel ratio, ignition timing, and boost-referenced fueling so the +110 whp is delivered reliably.

Fueling hardware supports that tune. The factory NC injectors are near their limit once the car is making close to 250 whp, so a set of DeatschWerks 350cc top-feed injectors gives your tuner the headroom to maintain a safe air/fuel ratio at wide-open throttle. Skipping the tune to save money is the single most expensive mistake you can make on a supercharged Miata — it is cheaper to budget for calibration up front than to replace pistons later.

Supporting Upgrades: Clutch, Cooling, and Suspension

The supercharger nearly doubles the torque going through the drivetrain, so a clutch upgrade is next on the list. An Exedy Stage 1 Organic clutch holds the added torque while keeping a streetable, OEM-like pedal feel — ideal for a daily-driven boosted Miata. Pair it with fresh fluids and you have a drivetrain that will live behind the Rotrex.

Cooling is the other half of reliability. A Mishimoto NC aluminum radiator adds capacity for hot Florida summers and track days, keeping coolant temperatures in a safe window when the supercharger is working. More power also exposes any weakness in the chassis: a set of Skunk2 Pro-ST coilovers (8 kg/mm front, 6 kg/mm rear) sharpens turn-in and puts the new power down out of corners, so your supercharged NC feels planted rather than just fast in a straight line.