Timing issues

[bradley029]

hello all I'm helping a friend with a 2012 Xterra 4.0 v6 and we were gonna add a couple degrees of timing and the tables looked foreign to me all the numbers were negative ,I'm used to tuning gm ls lt1 platforms but these tables threw me for a loop.if someone could give me a little input that would be awesome I've never seen an all negative table before .thanks for any info

[Zever]

If the tables are like what I've been working with in my 07 Z they are known as trimming tables. The ignition timing OS takes in a lot of inputs to determine the correct ignition timing. Inputs like multiplier tables for IAT, ECT, VVT POSITION, ETC... Not near as comprehensive as it is on GMs. On the Nissan, just add or subtract from the random numbers on the stock files, and adding 1 doesn't necessarily mean 1 degree. I'm boosted and I've got the timing pretty dialed in but it's a little bit of a guessing game with a lot of trial and error. Hope that helps

[vk56Titan]

What You Should Do Instead:

1. Log Actual Spark Advance
? Use HP Tuners VCM Scanner to log:
? Actual Spark Advance
? Knock Retard
? IAT, ECT, VVT values
? Tune based on what you see happening in real time, not just the editor tables.

2. Adjust Trims Carefully
? Try adding or subtracting small values (e.g., ?2) and observe change in actual timing via logs.
? Don?t expect a linear relationship.

3. Use IAT/ECT Trims to Your Advantage
? These tables are often easier to control than the base spark trims.
? On boosted setups, it?s common to pull timing via IAT instead of trying to adjust main spark tables.

⸻

TL;DR:

Nissan timing tuning in HP Tuners is not direct like GM.
You?re working with offsets, and the negative numbers are normal.
The only reliable way to tune timing is through live logging and trial-and-error.

Let me know what Nissan ECU you?re tuning and I can show you a logging strategy and adjustment method that works best.