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I have seen on some stock tunes that the oem ramps timing+/- in wot areas. I have also seen some ramping +/- with PE. Is there really any major benefit of ramping the timing down during peak torque areas?
I have heard some say if you lower timing at peak torque, then you can ramp in more timing after peak torque vs. just running a flat timing curve of say 24 across.
Interest in your opinions.
flat timing and flat fueling is not what the engine wants. period. you will gain more power and hold it longer by giving the engine what it wants. flat 28 degree's and 12.8 afr is leaving power on the table as this is not what the engine wants. ever.
It's done by lazy people who don't want to take the time to work with the engine, not against it.
Question to me is whether you get more power and more
efficiency out of a fat mixture and early spark, or lean
and late. This has a lot to do with combustion particulars
and I think you want to experiment unless you're following
a recipe that's been wrung out.
As an example if you have a finite burn time on the hole
then as RPMs run up you will start to lose ability to
convert the pressure pulse to mechanical energy -
either you fire early and oppose the crank for a bit,
or you fire late and send it out the exhaust unused.
At some point you'll want leaner (faster burn) to "fit
it all in the window" of the power stroke. Spark only
positions the burn, doesn't control its duration. For
a fixed duration there is a best timing of course.
And fat duration has value in terms of broadening
the pressure pulse and the delivered torque at lower
RPM where you can get it all done and harvested
within the power stroke (and furthermore, at the
best crank angle for converting pressure to torque
all-told).
ding ding dingQuote:
Originally Posted by Area47
richer mixture and less timing through the torque curve (generally 3800-4800 on LS engines depending on bore x stroke, cam, etc) and curving leaner with rpm and putting a little timing back in most definitely will make for the best performing engine. This tuning strategy works for all engines (NA) but every engine combination will create a different torque curve and peak depending on every aspect of the engine build.
This is what defines true top tier tuners - understanding the engine combination and then wringing out every last ounce of performance from said engine combo
and doing this while maintaining longevity, reliability....