KitCarlson
Well-Known Member
By reading many posts on this form concerning ignition timing, there are many views on the subject.
When tuning for performance, some often simplify. An example is to lock the timing advance to 32 degrees. That may work in a limited RPM range, for wide open throttle use, but is not optimal. The timing can be easily adjusted, and tests made for lowest ET, but there is still performance to be gained by proper timing curves, meeting engine requirements.
The next improvement would be mechanical advance, followed by the addition of vacuum advance. Going more refined is electronic advance with 3D RPM and MAP table. More refined is the addition of knock control, and temperature timing enhancements. With proper controls, an engine is tactile, it responds to the drivers needs based on throttle position and RPM.
Modern engines use electronic advance, our older engines may be retrofitted with improved ignition systems for improved performance. I have experience with successfully developing engine controls for 4 cylinder normally aspirated and turbo engines. I am now working on a COP ignition for 6 and 8 cylinder Mopars. My greatest concern, is will people understand the 3D nature of tuning to get the most of the system.
The system will be easily tuned while running, from inside the car by pressing buttons. Things like RPM, ignition timing and manifold are real-time monitored values. More on that later. I have done this since 2003 on several cars using my engine management system.
Back to our ignitions as the came from factory, mechanical advance distributors with vacuum advance. They provide a good starting point for tuning. By consulting the factory service manual, distributor specifications can be found and used as a starting point. Mopar tuned distributors based on carb, transmission type and other features such as CAP.
Here is an example for a 1966 Barracuda with 273 2B engine. The 2 2D timing curves are independent of each other. The ported vacuum at carb shuts off the vacuum advance when throttle is closed. I have use this to estimate the 3D equivalent as a staring point for a 3D ignition control. 3D controls rely on a central manifold vacuum source, not ported vacuum, but the nature of the table complexity provides the timing control as desired.
When tuning for performance, some often simplify. An example is to lock the timing advance to 32 degrees. That may work in a limited RPM range, for wide open throttle use, but is not optimal. The timing can be easily adjusted, and tests made for lowest ET, but there is still performance to be gained by proper timing curves, meeting engine requirements.
The next improvement would be mechanical advance, followed by the addition of vacuum advance. Going more refined is electronic advance with 3D RPM and MAP table. More refined is the addition of knock control, and temperature timing enhancements. With proper controls, an engine is tactile, it responds to the drivers needs based on throttle position and RPM.
Modern engines use electronic advance, our older engines may be retrofitted with improved ignition systems for improved performance. I have experience with successfully developing engine controls for 4 cylinder normally aspirated and turbo engines. I am now working on a COP ignition for 6 and 8 cylinder Mopars. My greatest concern, is will people understand the 3D nature of tuning to get the most of the system.
The system will be easily tuned while running, from inside the car by pressing buttons. Things like RPM, ignition timing and manifold are real-time monitored values. More on that later. I have done this since 2003 on several cars using my engine management system.
Back to our ignitions as the came from factory, mechanical advance distributors with vacuum advance. They provide a good starting point for tuning. By consulting the factory service manual, distributor specifications can be found and used as a starting point. Mopar tuned distributors based on carb, transmission type and other features such as CAP.
Here is an example for a 1966 Barracuda with 273 2B engine. The 2 2D timing curves are independent of each other. The ported vacuum at carb shuts off the vacuum advance when throttle is closed. I have use this to estimate the 3D equivalent as a staring point for a 3D ignition control. 3D controls rely on a central manifold vacuum source, not ported vacuum, but the nature of the table complexity provides the timing control as desired.
