Adjustable Timing Contro

The MSD Ignition Adjustable Timing Control (MSD 8680) is a precision engine management tool designed for serious performance builders and tuners who demand real-time ignition curve optimization. Whether you're dialing in a carbureted big-block, fine-tuning a street/strip hybrid, or maximizing power across variable load conditions, this adjustable timing control module gives you the ability to sweep and lock ignition advance independently of traditional distributor mechanical and vacuum systems. This is essential equipment for anyone running an MSD ignition system who needs to extract peak horsepower while maintaining drivability across the RPM band.

The MSD 8680 integrates seamlessly with MSD digital ignition boxes to provide adjustable spark advance curves without requiring costly engine dyno time for initial tune validation. Its compact design (6.4 x 3.2 x 6.6 inches) and lightweight construction (1.5 lbs) make it easy to mount under the dash or in the engine bay, while the precision potentiometer adjustment mechanism allows repeatable, incremental timing changes in degrees of crankshaft rotation. By decoupling ignition timing from mechanical advance weights and vacuum modulators, you gain independent control over initial advance, total advance, and RPM-based advance ramps—critical for optimizing combustion in modified engines with altered compression ratios, fuel octane requirements, or intake manifold designs.

Builders working with MSD ignition systems—particularly those running MSD boxes like the 6-series digital controllers—will find this timing control indispensable during the tune-up and testing phase. Street engines, bracket-racing vehicles, and high-compression forced-induction builds all benefit from the ability to dial in precise ignition curves without swapping distributors or mechanical advance components. Installation requires basic electrical knowledge and connection to a compatible MSD ignition box; detailed wiring diagrams are included. For anyone serious about extracting consistent power and drivability from a modified engine, the MSD Adjustable Timing Control represents a cost-effective, professional-grade solution.