I did a long post on this a week ago or so and had determined I'm getting true knock (even on a dyno tune). I determined it's true knock because I only have the knock retard when my timing retard is set at zero. It was tuned with it set at zero so in theory it shouldn't knock but motors see different loads and temps/humidity when on the road. There was no knock on the scans from the dyno runs but that was at W.O.Throttle. I'm seeing the knock at about 4,500 RPM in third gear at about 85% throttle after I've already been through 1st and 2nd at the same throttle position though 5000 RPM. It won't do it in 1st or 2nd gear at that throttle position ....my theory is the higher IAT by the time I get up to 3rd gear is the cause of the knock. I will get some retard as well from a roll in 2nd gear at WOT ...but the tuner thinks that is burst retard due to the sudden airflow change. I've noticed my timing will drift as high as 47 degrees when at the lowest loads and wonder if that could be the cause of the knock I get from a roll in 2nd gear. It would have to see load first before it takes the timing down from 47 degrees so there's a possibility it's getting a quick spike of true knock at the moment when you mash the gas at such high timing. I'm generally seeing about 4.5 ~ 6.0 degrees of knock retard and it looks real because the decay rate is very slow.

Now for my questions; Can the computer adjust spark for different loads above 100 KPA or is it just like fuel ....blind above 100 KPA and reliant on MAF and other tables? The reason I ask is it almost seems like I get more knock retard at 65 ~ 85% throttle than I do at WOT. Perhaps that is from the computer leaving more timing in at 65 ~ 85% than at WOT? ....or ....does the computer only adjust timing via RPM once you're above 100 KPA?

If it adjusts the timing by BOTH ... RPM and boost I think I'd be interested in having some timing reductions done at the loads slightly below WOT. This way my peak power from the dyno tuning will be unaffected and I'll be in a safer zone for the middle to high (but not highest) loads.

If that is not the case and the computer only adjusts timing via RPM once you're into the boost, I think I'm just going to get some Xylene and start mixing a little bit in with the 93 pump gas we have around here. I wouldn't want to remove timing if it's going to have to affect my max power output simply because I wouldn't know how much power I'd lose and wouldn't have honest dyno numbers in my sig anymore.

See if you think this timing could be a little too aggresive to be well on the safe side based on your experience with timing on boosted stock LT1's please. This is from the scan of my max power WOT dyno run:

Spark output:

Dead on 35 degrees from 2,200 RPM to 3,500 RPM (shouldn't it change some within that range? boost goes from 1.5 PSI to 3.2 in that RPM range), ..... then from 3,600 to 4,800 it gradually lowers from 35 to 30 degrees (in this range the boost changes from 3.2 to 5.5) ......then from 4,800 ro 5,800 it goes very gradually from 30 to 27, with a boost change of 5.5 to 7.8.

My A/F (wideband checked) is fairly safe being 12.2 thoughout most of the run ...only about .5 leaner when it goes to 12.7 or so above 5250 RPM. Tuner says it's normal and safe to go slightly leaner above the torque=hp point because the load isn't as high.

Summary= Do you think I need some timing removed at WOT just to be safe? Can I have some timing removed above 100 KPA without removing WOT timing? (somewhere in between 100 KPA and the max boost you can make at various RPM's)