BMW Electrical Sensors, Switches, & Relays for BMW X Series E70 (2007-2013)

Transform your N55-powered BMW with the Turner Motorsport B58 Ignition Coil Conversion Kit—the ultimate solution for ignition system reliability and performance. Designed to eliminate the notorious misfires and power loss caused by factory OE pencil-style ignition coils, this kit is a game-changer for stock and modified vehicles alike. Whether you're chasing more power or improved drivability, the B58 ignition coils deliver up to 2.3x more spark energy, unleashing the full potential of your engine.

Why upgrade? The answer is simple: B58 ignition coils outperform all other ignition upgrades on the market with unparalleled spark energy and reliability. Ideal for high-performance builds or daily drivers, this kit eliminates common ignition problems while supporting increased power demands from software tunes like MHD or BM3. Plus, with the included plug-and-play wiring harness and proprietary boots, installation is seamless—no cutting or splicing is required.

Features:

Up to 2.3x More Spark Energy: Maximizes overall performance, offering sufficient output for heavily modified engines. Plug-and-Play Installation: Includes custom brackets, wiring harnesses, and boots designed for factory mounting locations—no modifications needed. DME Compatibility: Compatible with factory engine management software for hassle-free integration. Rugged Durability: Bolt-on brackets are precision-machined from 6061-T6 aluminum with a sleek black anodized finish for a premium look and long-lasting performance. Proprietary Design: Boots feature a built-in 1k OHM resistor to prevent electrical contact failures commonly seen in other kits. Kit Contents:

(6) Turner Motorsport B58 Ignition Coils (6) Turner Motorsport B58 Ignition Coil Conversion Boots (6) Turner Motorsport B58 Ignition Coil Conversion Wiring Harnesses (3) Turner Motorsport B58 Ignition Coil Conversion Brackets Optional Kit Selections:

Spark Plugs: Bosch ZGR6STE2 (OEM) NGK 97506 (One Step Colder) Spark Plug Socket: Schwaben 14mm 12pt Magnetic Socket Schwaben 14mm 12pt Swivel Socket Turner Motorsport offers a comprehensive installation guide, including detailed removal instructions and high-resolution images. Visit the Installation Tab for the step-by-step guide to completing your ignition system upgrade.

Say goodbye to misfires and hello to unparalleled ignition performance with the Turner Motorsport B58 Ignition Coil Conversion Kit. Designed with precision and engineered for reliability, it’s the ultimate upgrade for your N55-powered BMW!

If you own an M57-equipped BMW, you already know this twin-turbo diesel powerplant is an absolute torque monster. What you might also know is that all that low-end grunt and high-compression diesel vibration wreaks absolute havoc on your accessory drive system.

From the factory, both the E90 335d and E70 X5 35d utilize a rigid alternator pulley. With each cylinder's fire, the crankshaft experiences a violent micro-acceleration. Because the alternator has a heavy internal rotor spinning at high speeds, it wants to keep spinning at a constant rate. When the engine suddenly slows down (even minutely between firing cycles), the alternator fights the belt. This constant tug-of-war results in extreme stress on your engine's belt-driven components. At best, it’s an annoying, unrefined chirp at idle; at worst, it’s a ticking time bomb for your expensive harmonic balancer.

To solve this issue, many enthusiasts choose to run a clutched alternator pulley (also called an overrunning alternator pulley). A clutched pulley allows the alternator to "freewheel" or coast when the engine slows down, completely isolating its rotational inertia from the belt drive to prevent component wear. While the N52's clutched pulley (12317560483) is a straight bolt-on, the offset is incorrect for the E70 X5 35d's accessory drive. Thankfully, our engineers designed this zinc-coated spacer to provide the precise amount of spacing needed to perfectly align the new pulley with existing belt drive components.