For Tuners That Don't Understand MBT & Ignition Timing

Why does tuning the ignition timing correctly for your specific engine make you more power? Ignition tuning is often misunderstood by those new to tuning, and it can have serious consequences when we get it wrong in a high load/high boost area of our tuning table/calibration map.

Using a low-load area of the map and a Haltech ECU-equipped Mitsubishi EVO 9 with a turbocharged 4g63, let's examine what advancing or reducing our ignition timing angle does via a torque optimisation test on a Mainline dyno.

We'll examine why we want to have our ignition angle spot on and where that place is in our compression stroke, as well as what happens when we stray too far on either side. We'll also consider some things that might prevent us from finding our MBT value, including knock/pinging/detonation/pinking, which is not to be mistaken for the commonly incorrectly used term pre-ignition.

Key Terms:
TDC = Top Dead Center
BTDC = Before Top Dead Center
MBT = Maximum Brake Torque or Miminum Best Torque
RPM - Revolutions Per Minute
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TIME STAMPS:
0:00 - Common Issue
0:13 - Getting It Wrong
0:22 - The Plan
0:37 - What Is Ignition Timing
0:51 - Combustion Misconception
1:13 - What Is Actually Happening
1:35 - TDC - Top Dead Center
1:53 - BTDC - Before TDC
2:10 - Load Vs RPM
2:24 - Combustion Pressure Graph
3:10 - Compression Begins
3:53 - Peak Cylinder Pressure
4:08 - What Happens When Timing Is Wrong
4:42 - Overly Retarded Ignition Timing
5:23 - Overly Advanced Ignition Timing
6:08 - The Goal Of Ignition Tuning
6:26 - Cylinder Pressure Data
6:44 - Torque Feedback
7:00 - Torque Optimisation/MBT
7:30 - Sweep Test
7:53 - Base Ignition Timing 3D Table
8:19 - Test Cell
8:56 - Dyno Demonstration
10:06 - Results
10:49 - MBT - Maximum Brake Tourque
11:21 - IMPORTANT TO NOTE!
11:38 - Knock/Detonation/Pinging/Pinking
11:57 - Just ONE Cell Optimised Here
12:11 - 1st Ignition Tuning Table Trend
13:04 - 2nd Ignition Tuning Table Trend
13:34 - Low Load
13:50 - High Load
14:02 - Final Notes
14:25 - BUILD.TUNE.DRIVE