Some newbie help please, KR worry

[slayermanny]

Hi, I'm just looking for a little bit of help with my tuning, not so much the right answer as a point in the right direction.

I've got my maf tuning for regular street driving down pat, its within 1% and doing very well. However, my concern has shifted over to knock.

looking at my histogram, if i leave it in average, its mostly 0. However, if i look at it in max value i start to see some unfortunate results. I've got up to 6* in some places and i'm pretty sure that's way too high. Also, the higher the engine temp and IAT, the more instances of KR i'm seeing. Now, i realize that is probably supposed to be like that, but do i have to tune it out? (lower high octane timing per cell) I'm using the tables that the cortex tune (93 octane) ran in my car, except i increased it 2* across the whole table. In most places i see no issue.

Should i only be tuning when the engine is colder? After installing my intake temp sensor in a more efficient place I'm seeing better and more accurate temps. I just want to make sure i'm doing the spark portion of all this right, before i take her to the track and do the actual WOT tune. Let me put up my tune and my log file.

1959519596

(I put the DFCO back on and the low octane table back to stock so i can driver her home)

[bluegoat06]

No, it's not supposed to be like that, the whole purpose of IAT correction is to fight the issue you're seeing in your logs. To make it short, light up a lighter inside your car on a fresh morning and observe the flame. leave the car in the sun with the windows closed, and by noon, repeat the same exercise, and observe how large is the flame now that the inside cabin temps have gone a lot higher. IAT spark correction removes timing from the base spark so that flame is not as large when temperature in the combustion chamber gets hotter and hotter, does it make sense ?

Load your factory Hi and Lo octane table, factory IAT Spark and factory ECT spark.
Load your factory Knock retard decay/decay rate table.

Then double the knock retard decay/decay rate table, and halve the knock retard attack/base retard table.
Halve the knock burst retard/base vs cylair delta

The IAT sensor is supposed to meter air intake temps inside the intake tract, nothing else. Don't place it outside their intended scope location.

Dial your fuel first, part throttle and WOT, once you're ready with WOT fueling, make the Lo octane table the same as the hi octane table.
Do 3rd gear runs to test KR, observe KR in the logs, and focus your attention in the WOT cell areas, .64 g/cyl and down, 1600rpm and up.
If no KR present, increase timing in the WOT areas by 1-2* in the Hi octane table, copy to the Lo, repeat 3rd gear test. if KR is present, clean from the Hi, copy to the lo, wash, rinse and repeat.

With 93 octane shoot for 24-25* by 6000rpm, with 91 octane, shoot for 22-23* by 6000 rpm. Observe the factory timing curve in the logs, it looks like a U for a reason, observe, don't change stuff just because you read how Cortex adds 5* here and there, or how people think more timing equals more power, the timing curve doesn't have to be flat, the timing table doesn't need to be incremented in blocks with flat numbers, like 25* all the way from 3000 to 6000rpm, at higher engine loads, less timing is required, at less engine load, more timing is required.

The knock sensors in this cars are more sensitive for a reason, use them to your advantage, they're better tuned from the factory that then old shit in LS1's. they do their job in a better way, after all, they're listening for knock events, if you need to know your knock retard is real, pump 2-3 gallons of 100 octane gas in your tank, and watch your supposedly "fake" KR disappear. This is an actual indicator that the fake KR wasn't that fake.

When KR is detected and it's persistent, the PCM will switch the readings from the Hi octane, and will favor a % of timing straight from the Lo octane table,and it doesn't go back to the Hi ocane table right away, it take time for that to happen, that's why people will tell you to leave it alone, they think it's fake because it goes away after a while, well yeah, it does it because of the knock learn strategies, not because it's fake, good think GM thought about it, Lol, but it's good to run a little bit more timing in the areas that can tolerate it, and less in the areas that won't, in other words, if you command 24*, but KR brings the timing down to 16*, try to run 20* instead, if KR doesn't pull that timing, you're running 4* above where the PCM thinks the engine should run because of KR. You can run more than 20* with 93 octane, with 91 octane, 20* can be a lot for the 5200rpm for example.

Once you're done with timing tuning, put your stock Lo octane table back, that would be your cushion for shitty gas, or lower octane gas, and anything in between.

Good luck.

[slayermanny]

Thanks a lot for the info, Bluegoat. I'll be trying all that out over the course of the week. I put in the HSRK because i have a Vararam and the MAF is sitting right infront of the engine, instead of off to the side and further away like the rotofab. The intake sensor is still in the air stream of the intake path, i didnt put it outside of the intake.