08/31/2026
Part 2 – MEST Tune Myth Bust (Timing Pulled Back)
As we mentioned in Part 1, We’ve received a number of calls and questions recently about a so-called “MEST” tune and whether we will run it.
The short answer remains No. Absolutely Not.
Recap - In Part 1 we programmed the timing and AFR tables to closely match the publicly promoted numbers:
• 44° of timing from idle to ~4000 RPM
• 32° from 4000 RPM to redline
• Commanded AFR / PE of 13.0:1
The vehicle immediately became finicky with starting issues, lost substantial power and drivability, and entered heavy audible detonation under load with significant Knock Re**rd (KR).
In this video short For Part 2 we pulled the low-RPM timing back while keeping everything else the same:
• 40° of timing from 0–4000 RPM
• 32° from 4000 RPM to redline
• Same 13.0:1 commanded AFR / PE
Then repeated as close as we could the same testing. The result? The vehicle was still finicky and still produced clear, audible spark knock (detonation) under load.
Pulling 4° of timing out of the lower range did not eliminate the detonation or restore proper drivability. This further demonstrates that the promoted settings operate far too close to (and in this case, into) uncontrolled combustion a.k.a. "Detonation".
REMEMBER: "Detonation" is never a tuning target. Nor should it be used as a guide.
If you can "hear" detonation, It is clear evidence that combustion is uncontrolled and is actively damaging the engine.
This is Part 2 of our short series documenting the results under controlled conditions.
Next up we'll cover some of the log setting for the timing and fuel tables along with data logs, knock activity, power comparison, and a safer calibration on the same vehicle using proper timing and fuel tables.
As we said in part 1, Every engine combination is different. Always use proper knock monitoring, quality fuel and delivery, good cooling, and application-specific tuning.
Remember: proper tuning is never one-size-fits-all, and detonation should never be used as a guide.
This post is intended to share real-world data and help educate the community about a potentially dangerous set of settings being promoted online.
We performed this test on one of our test vehicles solely to document the outcome and provide factual information.