Timing curve under WOT

[Megags]

I have a quick question for someone who knows 4g63 na's well.

Let me give a little background first...

I bought a datalogger and everything looks fine except I'm not sure how the timing curve is supposed to be. My timing starts low under full throttle (about 15 at 2k rpm's) and gradually builds till it hits about 4k rpm's where it stays platued at 23 degrees advanced as long as I'm WOT.

My question: Is the timing advance supposed to climb steadily and not flatline like I think it's supposed to?

P.S. If something is wrong with my car, please tell me how to fix it.

Any help would be much appreciated

 

[IceDragon]

Timing on my car never flat lines... it steadily increases as the rpm's go up... why, because the explosion front in the cylinder needs to push down the piston head, and as the engine's rpms raise, the spark to ignite needs to start sooner and sooner, so the timing advances more and more.

 

[Megags]

Thats what I thought after all I had been reading. That it should go up to about 33 degrees advanced. I didn't mean I thought it was supposed to flatline, though it looks that way. Thanks for the help (I know how the engine works), but it still doesn't fix my problem as to why it doesn't go up higher.

 

[StreetSleeper34]

It should gradually increase under normal acceleration, being at it's highest during highway driving. I have mine advanced a bit, so for example it will get up to 40-45 at 75mph @3500rpms. But under WOT, the ECU will pull the timing back down to the low 20's and remain there until you are not WOT anymore. Mine drops to 21-24. At idle, mine sits around 8-12 when warmed up. It sounds like this is how your car is running, but if this pattern is not occurring with your logger, then something may be wrong.

 

[Megags]

That's exactly what it's doing. It hovers from 20-24 during wot. At a cruise it is a steady 35ish, but between shifts goes up as high as 45 sometimes.

With that said, would it be safe to advance the timing another 5-10 degrees via the camshaft sensor? The logger shows my fuel trims at 100H, 105M, 114L on average.

 

[StreetSleeper34]

That's exactly what it's doing. It hovers from 20-24 during wot. At a cruise it is a steady 35ish, but between shifts goes up as high as 45 sometimes.

With that said, would it be safe to advance the timing another 5-10 degrees via the camshaft sensor? The logger shows my fuel trims at 100H, 105M, 114L on average.

Well with all the mods that I have done to mine, I only advanced the base timing 2 degrees. It now sits at 7 on the gun. It may help a little bit to advance it, but without having a mod list to back it up, there may be no noticable gain or reason for doing it now. I wouldn't go too extreme though, many would consider even the 2 degree base that I advanced it to be fairly risky. Might want to hold off on doing that until a little later on. But it only takes a few minutes to do it and see if you can tell anything. May not hurt to test it out, and if there is no noticable gain, then I would go back to factory specs for the time being.