Note: Data for each tune is shown individually on this page.
Average WHP Chart – Summarizing Three Pulls:
Average WTQ Chart – Summarizing Three Pulls:
3 Pull Average Peak WHP Comparison:
3 Pull Average Peak WTQ Comparison:
Primary Engine Variables
Average AFR
Average Boost
Average Timing
4th Gear Noise Thresholds:
This section addresses the engine noise level on the dyno in fourth gear. The topic of noise level and the relationship with knock (detonation) are discussed in detail on this page.
Click below to show a brief overview of the relationship between noise levels, the noise threshold, and ECU safety measures.
Knock and Noise Introduction
Knock Retard / Timing Reduction is something that the Cobb Accessport reports, but this value does not necessarily correlate with Knock Activity.
The noise signal picked up by the knock sensor is evaluated against criteria that can be modified by tuners. This can alter the ability of the ECU to respond to potential knock (detonation).
In this first example, an OEM-like Knock Threshold is shown.
The Noise Signal (Blue line) from the knock sensor spikes above the Knock Threshold (Red line), and the ECU reacts to the potential Knock Event by reducing Ignition Timing (Knock Retard) (Cyan line), and the Accessport reports a value for Ignition Timing Retard on Cylinder #1.
In this next example, a tune with the Knock Sensors “Numbed” is exposed to the same Noise Signal (Blue line) spike.
The difference in this case is the tuner has raised the Knock Threshold (Red line) so the ECU does not process this noise spike as a potential Knock Event and no safety measures are employed.
The Accessport reports zero (0) for the Ignition Timing Retard on cylinder #1 even though the same potential Knock Event has occurred as in the first example.
These examples illustrate why the Ignition Timing Retard value reported by the Accessport can be of little value when aftermarket tunes are installed on an ECU.
Knock Sensor Numbing
In the next charts, the amount of Knock Sensor Numbing relative to the OEM values is shown. Higher percentages indicate a greater “numbing” of the Knock sensors compared to the OEM safety margins, increasing the probability of engine knock not being addressed by the ECU.