87 vs 91/93 Timing Differences

[Nick912]

Hi everyone,

I'm planning on taking my car on an 1800 mile road trip soon, and would love to save some money running 87. I would prefer changing the high octane spark table myself rather than rely on my knock sensors to switch me to the lower table. Car runs optimally with my current spark set at 27.5 degrees at WOT on 91, but not sure where to bring spark down to with 87 in the tank. How much spark should I take out up top to get me in the ballpark? Is there any reason I'll have to change spark at lower load conditions? Thanks in advance.

[5FDP]

Without knowing what you drive or what you even have done to the engine just remove 7-8 degrees of timing.

Low load area's don't need to change in my opinion. It's a road trip so you don't really need to floor it much anyway.

[Alvin]

Tip in.. like where it is loaded when the converter is locked and your going up a hill would be another good spot to pull timing.. You could go to stock timing tables for it?? Or skip the snickers bar and give your car premium

[Nick912]

Thanks for the input, Sorry about the lack of info, here's my current setup:

2011 Camaro LS3 M6
Long Tube Headers into 3in exh
Cold air intake
Cam: 235/248 111LSA 109.5 ICL
Stock heads and rotating assembly (10.7 static CR)

After this road trip, I am pulling the motor and building a forged 416, so I'm not too worried about much as of now. One question I do have about the high and low octane spark tables: once a knock learn factor occurs from repeated knock events, how long does this learn factor stay active for? Does this reset when the car is restarted, or will the learn factor be active until the next tune flash? I just did a nice long log re-dialing in the MAF (still running 91 as of now) and the knock learn factor I acquired stayed for the duration of the log. I'll post the tune I was running along with the log, but this question is more general than anything.

MAF tune step 4.hptMAF tune step 4.hpl