In this episode of the “On the Dyno” series, host Bob Morreale dived into two common tuning mistakes encountered during engine tuning, particularly with LS and LT engines. The primary focus was on the dangers of too much spark advance and the pitfalls of ignoring knock sensor warnings. Bob explained the process of tuning spark advance by illustrating how power gains increase with incremental spark timing but eventually reach a point of diminishing returns. Past this point, adding more spark advance not only fails to provide significant power improvements but also introduces knocking, which can damage the engine. The second major mistake is “letting it ride the knock sensors,” where tuners allow the engine to operate with knock events happening, under the false assumption that minor knock detections during tuning are safe if power gains are noticed. Bob warns this is an unsafe practice because knock sensors are reactive—they detect knock only after it happens, potentially causing long-term engine damage. Instead, he emphasizes that a good tuner watches trends carefully, steps back when knock arises, and avoids aggressive spark timing that risks reliability. He advises users with scanning tools to monitor knock activity during real driving conditions, noting that persistent full-throttle knock and the ECU pulling timing indicate a problem that needs correction. Overall, the episode highlights the importance of cautious, incremental tuning and not risking engine health for marginal power gains.

Highlights

⚙️ Incremental spark advance increases power but only up to a safe threshold.

🔥 Too much spark advance causes knocking and potential engine damage.

📊 Power gains diminish as spark advance approaches the limit, signaling caution.

🚫 “Letting it ride” knock sensors is dangerous and unhealthy for the engine.

📉 Knock sensors react after damage begins; they do not prevent it proactively.

🛠️ Good tuning requires observing trends and pulling back when knock is detected.

🔎 Drivers should use scan tools to monitor knock during real-world driving conditions.