Got it. Tks.

I think you can ignore those knocks at 85 kPa and below. But, might still do this:
Using your 32* table, I'd just reduce spark in increments of 0.5 degrees at 85 to 95 kPa between the RPMs reporting...

Thanks Dave!

No need for trailer :nono:. Reviewed your knock reporting again. Forget the 3rd/4th gear test. Only need hard accel. Strange no knock at 100 kPa. Using your 32* table, I'd just reduce spark in...

Sorry, but I use TPro so can't use a .dat file.

My take is that 32* is pushing it. A random knock here and there is a non-issue and likely due to vibration. Only concerned generally when prolonged...

Hard to tell the chamber design from pic but generally a fast burn chamber will be in the 62-65cc range (your's 62cc), and will need much less spark than larger due to the better burn (eg-Vortec iron...

Interesting. 32* may be the sweet spot if not slightly more. Generally AL heads can tolerate more spark than iron, naturally subject to chamber design, comp ratio and octane. Your spark is more in...

Very interesting Dave. But look at all the gyrations. No way anyone could come up with a spark map like that without a dyno. That's why I chose to develop the smooth curve.

Agree with Fast355 that dyno is only way to really measure objectively, but SOTP feel for most is all that's practical.

PlayingWithTBI - Sounds like all-in might be reduced to 30-31* to see if...

Interesting. If I'm looking at this BIN correctly with a $0D XDF, Spark is all-in at 4400-4800 with max of 27.4 deg, then after 4800 it drops to 26.0 deg up to 6000. Would be interesting to know if...

One last note on this. Will agree with lionelhutz there does not appear to be anything (at least written) to indicate ramping down timing after all-in RPM. But if you look at the $8d spark tables...

OK, which is what I was trying to say: And the amount of timing reduction in the example may not work for everyone. Maybe it should not be reduced at all.

Admittedly, I'm not a timing expert. And the amount of timing reduction in the example may not work for everyone. Maybe it should not be reduced at all. It depends on many factors because every...

Here's a fool-proof technique to build a Spark Table. It does not follow the GM model where spark is all over the place. It works much better. Agree with Fast355 that Vortec heads should max out at...