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Negative Ignition Timing on Steady State Datalog

Practical Reflash Tuning

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Hi, Im using COBB Accesport with OTS map: Stage 3 LWG ACN91 Fuel on Evo X

I dont know why mi car is getting Negative ignition Advance under low RPM and low Load,....I completed Practical Reflash Tuning course and began training on my cars to first Calibrate MAF and Speed Density.

I donwloaded MegaLog HD to get the Histograms and i see that im getting a lot of retard on spark. Pics attatched

There is no Knock detected, but i see that the AFR's are Lean near those negative timing areas

Attached Files

Looks to me (based on the graph at the bottom of "timing-issue.jpg", at all the negative ignition timing is on overrun, or trying to enter idle. Looks pretty normal to me.

the Graph track is based on time, not exactly in the Histogram Cells order.

whats the meaning of Overrun?

you say that when the car enters to idle we can expect to have negative ignition timing?

I clicked on Play Back for Graph, and i noticed it happens when i release the pedal to shift into gears, and for example if im in 3rd gear and release Throttle to stop on red light.

Exactly. So you aren't concerned with making power, but you do want to keep the turbo energy up, with retarded ignition timing if Anti-lag is enabled.

Overrun is when the engine is being driven by the car (ie, coasting down a hill with essentially a closed throttle). Or the throttle is closed and the engine is decelerating.

Using the graph, you can see the ignition timing trace, and noticed when it moved toward the bottom (negative values) -- then look at the other traces -- what is the throttle and/or RPM doing at that time -- I see overrun, and entering an idle condition. So something in your ECU configuration is causing that to happen - I think it's OK, but if you don't want that -- now you know what conditions cause it so you can modify the correct table or parameter.

Lol, I dont Know if COBB OTS Maps have Anti Lag have antilag.

If you say its OK i think i dont have to spec any problem.

However thanks for update my knowledge.

Does it matter while on overrun if the ignition value is negative or positive?The throttle is closed anyway.