Viewing the “trail” of electrons: One of the most enjoyable aspects of working with a dynomometer while performing high-performance tune ups on “Muscle Cars” is witnessing the positive results. On earlier-model cars with carburetors and distributors, the capability to re-calibrate and re-jet carburetors as well as modify/ optimize the centrifugal distributor advance mechanisms (spark “timing”) made the job of “Dyno Tuning” more rewarding.
Depending on the model of car and the type of equipment on the engine, both maximum horsepower and the breadth of the power across the range of engine speeds can be altered. While the view of the scope ignition/spark pattern here is just to confirm the condition and performance of spark firing lines/patterns, the corresponding dynamic (power delivered to the wheels on a dynomometer) monitoring of the engine output added extra engine tuning/calibration insight (and intrigue with the task).
One of the most immediate and predictable performance increases we made in the shop was to re-curve the distributor ignition timing to deliver optimum ignition advance at the lower end of the engine speed. While working to be sure not to over-advance the ignition (which would certainly result in detonation, or “pinging,” and resulting damage and/or excess heat in the combustion chamber), we would tailor the ignition advance to come in as quickly as possible – resulting in increased “seat-of-the-pants” and actual acceleration advantages.
On the carburetion side, using an exhaust-gas analyzer in combination with the dyno, we were able to optimize the air/fuel ratio – especially under “full-throttle” load. Sometimes the exhaust gas meter readings would call for increased fuel (richer) carburetor calibrations, while often the tailoring of carburetion called for decreased fuel (leaning) carburetor adjustments for maximum performance.
In any “Muscle Car” the ultimate satisfaction is when putting the engine and drive train under full load. “Dyno Tuning” is the detailed tailoring and customizing of the ignition and carburetion to maximize spark and air/fuel delivery performance under all conditions. While factory settings would frequently deliver great performance, “dyno tuning” was especially ideal for cars as they aged, and needed refining to their “blue print” factory specifications.