Ignition advance

Hi @Andre

I have seen this video multiple times and little confused

https://www.hpacademy.com/dashboard/courses/road-tuning/steady-state-ignition-tuning-mbt-tuning/

From what I understand, the higher the rpm the more advance you would want as long as car is not knock limited. What I don't get is you state the higher the load, less advance is needed. I am thinking at wide open throttle, and high rpm, you would want as much advance as possible close to mbt as long as car is not knock limited, am i incorrect?

could you clarify please?

With a higher load, more air-fuel mixture needs to be drawn int to the cylinder and burned, to counter the higher torque demanded. This means a denser charge in the cylinder and a denser charge burns more quickly than a less desnse one. So, this means less timing can be used - all other things being equal - because otherwise the pressure rise balance will be too early and/or cause detonation problems.

There are two primary factors for the ignition timing - a/ RPM, as the higher the rpm the less time the engine has to burn the fuel and the earlier the timing need to be to get the best cylinder balance before and after TDB for best torque; and b/ the density of the charge in the cylinder as denser charges burn faster.

That is, of course, provided detonation, or other issues, doesn't prevent timing for best torque.

I follow now so higher density means quicker burn hence leas timing

thanks for taking time to explain it:)