Discussion and questions related to the course Introduction to Engine Tuning
How much ignition advance at low load and 12.7 compression ratio?
That depends on the fuel, RPM, combustion chamber design, spark plug location. What is low load (idle? cruise? 10% throttle?, 70kpA?).
Correct answers could range from 20 - 60 degrees.
yeah it could definitely be in the 40 to 60 degree range due to very slow burn, but it's going to vary.
Low load at cruise with 50-60 kpA and 10% throtle about on 3000-3500RPM ?
The main thing you want to avoid is surging/hesitation/misfire from too little spark advance. You can feel the torque jump up and down if it doesn't have enough spark.
Hi Nick, nobody is going to be able to give you an exact timing value that will be perfect. this needs to be found through testing on a dyno. We sweep the timing through a wide range and measure the affect on torque. We can then see what the optimal timing angle for that particular combination of load and rpm is. It will vary dramatically based on all the parameters David mentioned above.