5 Pro-Comp Tach 900

OVERVIEW

When you''re pushing a high-performance air-cooled engine to its limits, precision isn''t just a luxuryit''s a requirement for survival. The AutoMeter 5-inch Pro-Comp Tachometer (ATM6852) is the industry standard for serious Volkswagen enthusiasts, drag racers, and off-road warriors who demand absolute accuracy. This isn''t your average dashboard clock; it is a professional-grade instrument featuring AutoMeter''s legendary air-core movement, designed to provide lightning-fast needle response while remaining rock-steady under the intense vibrations of a high-revving flat-four. Whether you are staging at the Christmas tree in a Pro-Stock Beetle or rowing through the gears in a sand rail, this tachometer ensures you know exactly where your power band sits at every millisecond.

The standout feature of the Pro-Comp 900 series is the integrated two-stage shift light system. This advanced configuration allows you to set two distinct RPM points, giving you a tactical advantage during competitive driving. You can program the first stage for a specific launch RPM or a "warning" shift point, while the second stage signals the ultimate shift limit to prevent over-revving and potential valve float. The classic black face with high-contrast white numbering and a vibrant orange needle provides effortless readability in both direct sunlight and the dark of night. Wrapped in a rugged silver bezel and featuring a pedestal mount, this tachometer adds a period-correct "competition" look to any VW interior while delivering modern, race-winning technology.

FITMENT

This universal high-performance tachometer is designed for 12V electrical systems and is compatible with 4, 6, and 8-cylinder engines. It is a favorite for the following applications:

• Volkswagen Beetle: 1949 through 1979 (All Type 1 Sedan and Convertible models).
• Volkswagen Karmann Ghia: 1955 through 1974.
• Volkswagen Bus / Transporter: 1950 through 1979 (Type 2 Bus, Kombi, and Campmobile).
• Volkswagen Type 3: 1961 through 1973 (Squareback, Fastback, and Notchback).
• Volkswagen Thing: 1973 through 1974 (Type 181).
• Custom Off-Road: Dune Buggies, Sand Rails, Manx-style buggies, and Baja Bugs.
• Race Chassis: Tube-frame drag cars and specialized air-cooled competition vehicles.

SPECS

• Brand: AutoMeter.
• Series: Pro-Comp.
• Part Number: ATM6852.
• Gauge Diameter: 5 Inches (127mm).
• RPM Range: 0 to 9,000 RPM.
• Shift Light Type: Integrated Two-Stage Quick-Lite (Amber/Red).
• Movement: Race-proven Air-Core for maximum durability and speed.
• Face Color: Traditional Black with White Digits.
• Pointer Color: Fluorescent Orange.
• Bezel Color: Silver / Brushed Aluminum.
• Lighting: Perimeter Incandescent (Bulb and Socket assembly).
• Signal Compatibility: Works with standard points, electronic ignitions, and most high-output CDI ignitions (like MSD).
• Mounting: Pedestal mount included for dash-top or steering column installation.

PRO TIPS

1. Proper Grounding is Critical

Air-cooled Volkswagens are notorious for grounding issues due to their body-on-pan construction and aging wiring harnesses. When installing your AutoMeter Pro-Comp tach, do not rely on a simple sheet metal screw into the dash for your ground. For the most accurate RPM signal and to prevent "needle bounce," run a dedicated ground wire directly to the chassis or the engine block. A clean, solid ground ensures that the sensitive air-core movement receives a pure signal without interference from other electrical components like wipers or headlights.

2. Ignition System Compatibility

If you are running a high-energy ignition system such as an MSD 6AL or a similar CDI box, you must connect the tachometer''s signal wire (usually green) to the "Tach Output" port on the ignition box rather than the negative side of the coil. Connecting directly to the coil on a CDI system can provide a signal that is too "noisy" or high-voltage, which may damage the internal circuitry of your ATM6852. If your needle appears erratic or stays at zero after upgrading your ignition, you may need an AutoMeter Tach Adapter (Part #9117) to square up the signal.

3. Utilizing the Two-Stage Shift Light

To get the most out of the two-stage feature, think about your driving style. Many drag racers set the first stage (the smaller light) at a "readiness" RPM, such as 500 RPM before the actual shift point, to prepare their reaction time. The second stage (the bright Quick-Lite) should be set exactly at your peak horsepower RPM or just before your engine''s redline. Remember that your engine revs faster in lower gears than in higher gears; setting your shift points slightly lower in first and second gear can help account for your human reaction time and prevent hitting the rev limiter.