Introduction

The AMS Alpha 9 Turbo Kit is engineered specifically for the BMW M4 (F82/F83) to deliver a reliable 750+ horsepower while maintaining daily drivability. Whether you’re building a street monster or a track weapon, this installation demands precision, patience, and proper preparation. This guide expands on every phase of the process, from workspace setup to initial tuning, so you can execute the install with confidence.

Preparation: Tools, Workspace & Safety

Before touching a single bolt, ensure your environment and tool collection are ready. A clean, well-lit garage with a level concrete floor is ideal. You will need assistance for heavy lifting (turbo assembly, front bumper handling).

Required Tools & Materials

  • AMS Alpha 9 Turbo Kit (confirm all components: turbocharger, manifolds, downpipes, charge pipes, intercooler, intake, wastegate, blow-off valve, oil/water lines, gaskets, fasteners)
  • Socket set (metric, deep and shallow, 8mm–19mm; swivel extensions helpful for tight spots)
  • Torque wrench (two ranges: 5–50 Nm and 20–200 Nm)
  • Screwdrivers (flathead and Phillips, long reach)
  • Pliers (standard, needle‑nose, and hose clamp pliers)
  • Trim removal tools (plastic pry bars for bumper clips)
  • Heat‑resistant gloves and safety glasses
  • Shop towels and a drain pan (5‑quart capacity minimum)
  • Engine oil (high‑quality synthetic, 5W‑30 or 0W‑40 – check AMS recommendations)
  • Coolant (BMW approved G48 or equivalent pre‑diluted)
  • Threadlocker (medium strength, e.g., Loctite 243)
  • Anti‑seize compound for exhaust fasteners
  • Jack and jack stands (or lift)

Vehicle Preparation

  • Disconnect the battery negative terminal. Wait 10 minutes for DME capacitors to discharge.
  • Allow the engine to cool completely (overnight is best) before draining fluids.
  • Remove the engine underbelly panel and lower front splash shields.
  • Drain engine coolant from the radiator petcock and remove the expansion tank cap to speed drainage.
  • Drain engine oil (best done after removal of stock turbo to catch any residual).

Important: Read the entire AMS Alpha 9 manual before starting. Note any torque specifications and special instructions for your specific kit revision.

Removing Stock Components

Systematic removal prevents damage to sensitive parts and saves time during reinstallation. Work from front to back, top to bottom.

Front Bumper & Front End

  • Remove bolts along the wheel well liners (T25 and 10mm) and six 8mm bolts across the top of the bumper under the hood.
  • Unplug fog lights, adaptive cruise sensor (if equipped), and side marker lights.
  • With assistance, pull the bumper forward and set it aside on a soft surface.
  • Remove the radiator support cross‑brace and the active grille shutters (if present) for better access.

Stock Intake System

  • Unclip the air filter boxes and remove them with the intake ducts.
  • Disconnect the MAF sensors and set them aside.
  • Remove the charge air cooler (intercooler) by releasing the four lower bolts and two upper brackets – note that coolant lines may need to be disconnected.

Stock Turbocharger & Exhaust Manifold

  • From underneath the vehicle, remove the downpipe and O2 sensors. PB Blaster helps loosen rusted nuts on the exhaust manifold.
  • Disconnect the oil supply line, water lines, and coolant return line from the turbo cartridge.
  • Remove the turbo heat shield, then unbolt the turbocharger from the manifold (four nuts, 15mm).
  • Remove the exhaust manifold bolts (reverse order of tightening) and lift the manifold with the turbo attached.
  • Clean the cylinder head sealing surface with a plastic scraper – no residue from old gaskets.

Note: For 750+ hp, consider upgrading the fuel system at this point. AMS recommends installing larger fuel injectors (e.g., 1300cc or higher) and a high‑flow in‑tank pump along with a low‑pressure pump (if running full e85). Plan accordingly, because fuel rail and line access is easiest while the turbo system is being overhauled.

Installing the AMS Alpha 9 Turbo Kit

Follow the kit’s included instructions closely, but the following sequence has proven reliable on many builds.

Exhaust Manifold & Turbo Installation

  • Apply a thin coat of anti‑seize to all exhaust studs. Install the new AMS manifold using a new gasket. Torque to manufacturer spec (typically 18 Nm in multiple stages).
  • Mount the Alpha 9 turbocharger to the manifold with supplied gaskets and lock nuts. Torque to 25 Nm.
  • Connect the oil feed line (restrictor may be included – confirm orientation). Torque the banjo bolt to 15 Nm.
  • Route the coolant feed and return lines. Use threadlocker on the banjo bolt threads.
  • Install the oil drain line with a new gasket – ensure it routes downward without sharp bends.
  • Attach the wastegate actuator arm to the wastegate flap. Adjust preload according to AMS instructions (usually 3–5 mm of rod travel).

Intercooler & Charge Pipes

  • Position the AMS intercooler in the front bumper opening. Secure with supplied brackets and hardware.
  • Attach the aluminum charge pipes from the turbo outlet to the intercooler. Use T‑bolt clamps and ensure all couplers are seated fully.
  • Install the blow‑off valve on the specified charge pipe. Route the vacuum line to a manifold vacuum source (not boost reference).

Intake & Air Filter

  • Mount the AMS enclosed intake or filter assembly (depending on kit variant). Connect the MAF sensor housing and ensure the fitment is snug against the chassis to avoid rubbing.
  • Double‑check that all silicone couplers are free from oil residue before clamping.

Downpipes & Exhaust

  • Install the AMS downpipe (catted or catless) to the turbo flange using new gaskets. Torque the four nuts to 20 Nm.
  • Reinstall O2 sensors – ensure the downstream sensor (post‑cat) is not wrapped around sharp edges.
  • Connect the downpipe to the rest of the exhaust system. If your M4 has factory exhaust, consider a full 3‑inch cat‑back for minimal restriction at 750+ hp.

Fluid Lines & Wiring

  • Reconnect the coolant expansion tank and fill with BMW approved coolant. Install a new cap.
  • Reconnect the oil drain plug and refill with 6.5 liters of fresh oil (confirm dipstick marking after initial run).
  • Plug in all sensors: MAP sensor, IAT sensor, wastegate solenoid (if using boost control), and any additional AMS harness connections.
  • Secure all wiring away from hot surfaces using heat‑resistant zip ties.

Front Bumper & Final Mechanical Assembly

  • Reinstall the front bumper support and the bumper itself. Verify that intercooler and charge pipes are not contacting the bumper skin.
  • Reattach all electrical connectors for fog lights, sensors, and side markers.
  • Install the underbelly panel and wheel well liners.
  • Reconnect the battery.

Initial Startup & Leak Testing

Before firing the engine, perform these critical checks:

  • Pressurize the intake system (with a boost leak tester) to 20 psi and listen for hissing. Cover all charge pipe connections, throttle body gasket, and intake couplers.
  • Inspect all oil line fittings for seepage. Tighten any suspect connection.
  • Crank the engine with the fuel pump fuse removed for 10 seconds to circulate oil before full startup.
  • Start the engine and let it idle. Immediately check for oil pressure (OEM gauge should show at least 20 psi at warm idle). Watch for coolant leaks around the turbo water lines.
  • Run the engine at idle for two minutes, then turn off and recheck all fluid levels.

Tuning & Break‑In for 750+ Horsepower

The AMS Alpha 9 is capable of 750+ whp on pump gas with methanol or race fuel, and safely over 850 whp on e85. However, a proper ECU tune is mandatory. Use a reliable platform such as BootMod3 or MHD (for supported DME) with a custom calibration from a known tuner (e.g., Wedge Performance, DME Tuning).

For initial tuning:

  • Flash a base map appropriate for your fuel type and injectors.
  • Perform a short road test at light throttle (no boost above 5 psi). Log fuel trims, boost response, and AFR.
  • Return to the shop and perform a boost leak test again after heat cycling.
  • Begin incremental pulls on a dyno or safe road to dial in timing and boost. Target a conservative 18 psi on pump gas, 23 psi on e85.

Important: Do not attempt boost runs without a wideband O2 sensor log and knock detection. Failure to tune properly can destroy the engine in seconds.

Supporting Modifications for 750+ HP

To reach and maintain 750+ horsepower, the turbo kit alone is not enough. Consider these upgrades during installation:

  • Fuel system: Port injection or upgraded direct injectors plus a second low‑pressure pump (e.g., BMW PI kit from Fuel‑It).
  • Transmission: If automatic, a ZF8HP torque converter upgrade and transmission tune. If manual (rare in US M4), a heavier dual‑mass flywheel and upgraded clutch.
  • Cooling: An additional oil cooler (Setrab or CSF) and a larger auxiliary radiator help sustain high‑power pulls.
  • Engine internals: The S55 block is strong, but for sustained 750+ hp, billet main caps, forged pistons, and rods are recommended.

Common Pitfalls & Troubleshooting

  • Boost leaks: Most common issue. Always test after installation and after first heat cycle.
  • Oil leaks at turbo drain: Ensure the drain line is not kinked and is higher than the oil pan return level.
  • Wastegate rattle: Adjust actuator preload and check for flapper clearance. AMS provides a turnbuckle for fine adjustment.
  • Coolant expansion: Use the factory bleed procedure (run heater on high, idle with pressure cap loose) to clear air pockets.
  • Check engine light: Often due to O2 sensor placement or missing catalytic converter. A proper tune will disable irrelevant codes.

Conclusion

The AMS Alpha 9 Turbo Kit, when installed with precision and supported by a robust fuel system and tune, transforms the M4 into a serious high‑horsepower performer. Take your time on each step, verify every connection, and trust a professional tuner to finalize the calibration. For additional resources, consult the official AMS Performance website for product support and the Bimmerpost F8X forum for real‑world build threads. If you are uncertain about any mechanical step, consider enlisting a certified speed shop – 750+ hp leaves no room for shortcuts.