Description
Mechman 400-amp Machined Billet alternator for select Audi / VW applications
This listing includes:
- (1) Mechman B11723400M Billet Alternator
Introducing the brand-new 100% custom billet alternator designed specifically for Audi and VW vehicles. This high-performance alternator eliminates the need for the weaker, factory-style alternator case, offering a significant upgrade with Denso-based components known for superior quality and efficiency. Built with the same internals as Mechman’s signature GM Billet 400-amp alternators, this model excels in performance, aesthetics, and reliability.
This alternator delivers 200+ amps at idle and over 400 amps at driving RPMs, making it an ideal choice for those seeking to increase their vehicle’s electrical output. Paired with a good battery or battery bank, it provides ample power for various automotive needs.
Installation Details:
- Charging System: The alternator uses a robust GM-style 4-pin regulator, producing a steady 14.6-14.9 volts. This regulator does not reuse the weaker OEM voltage regulator. Installation requires a simple 12V key on/off circuit connection, similar to a car audio amplifier’s “remote turn on wire.”
- Note: This setup may trigger a “charge battery” code, but rest assured, the alternator will charge perfectly fine.
- Idle Charging: A 46mm pulley ensures excellent charging at idle. A belt approximately shorter than the OEM is needed. Belt size may vary based on vehicle modifications. Use the OEM spring tensioner location to verify proper fitment. Mechman offers a convenient Quick Belt Finder on their website to assist in sourcing the correct belt.
- Wiring: For optimal performance, 0-gauge power and ground wires are required from the alternator to the battery. OEM wiring can remain in place, but these additional wires ensure maximum efficiency.
Additional Notes:
- This alternator comes with a 7-rib pulley to accommodate varying mid-model year changes and retrofits. If your vehicle uses a 6-rib belt, the extra rib on the 7-rib pulley will not affect performance or cause any fitment issues.
- This custom billet alternator is the perfect upgrade for Audi and VW owners seeking improved power and reliability without compromising on quality.

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