Ignition advance curve?

[tuningnoob1988]

So ive got a question regarding ignition timing.

Ive experimented with tuning different cars over the years, mainly boosted stuff, and ive seen a lot of different tune files and logs. Ive noticed some very different timing curves from different tuners at WOT.

Ive seen timing curves where the timing comes in slow and steady with RPM but to the point where you dont really see peak ignition timing until practically redline. So on every shift, timing might drop to say 10 degrees and then slowly work its way back up to 18 degrees or something by the shift.

Ive also seen logs where the timing "curve" is literally a flat line, so through the powerband, 5-7k rpm or w/e the timing is just pegged flat at 18 degrees.

Id assume having more timing through the entire powerband would result in more power?

Is there actually a reason to bring timing in slowly at that point in the powerband assuming there is no knock running a flat 18 degree curve at that point?

Is it just done to be less stressful on the engine?

[Higgs Boson]

spark lead should be set to MBT using a dyno. anything else is a guess.

[32vape]

It really depends on the setup and fuel. A big cam n/a on e85 will usually have a pretty flat timing curve with maybe a slight dip before and after peak torque. A Magnuson at 10 psi on a stock engine with 93 you have to ramp in the timing all the way up. As Higgs said it takes a dyno to dial it in.