It’s even easier on an engine dyno. You can load it up and move the timing around while watching vacuum, torque and horsepower.
I have a 3 step retard in the shop that is going out Monday to get rewired. With that, I can sit at the desk and change the timing and know exactly how many degrees I’m moving it and watching the numbers.
Then you take that data and curve the distributor to get the curve it likes the best.
You can’t do that on an inertia chassis dyno (or the far more rare crank inertia dyno) because you can’t get a steady state load on the engine.
BTW, you can do the same thing when changing your emulsion/bleed package.
