Navy David SS

iTrader: (13)

When does the high octane take over from the low octane tables on LS1 Edit?

The reason I ask is that I just completed my new set-up Stage II heads and TSP cam. Did some initial break in and put it on the dyno on Saturday.

After a couple pleminary pulls, my first 4th gear pull was only around 368rwph . On the A-tap (and dyno) running very rich (11.3 AF) and only 19-20 degrees of timing, with no KR, no mis-fires. Everything else seemed normal.

Leaned out via the PE vs RPM table (98% from 4200-6000; 97% 6200-7000). Pulled 388 rwph. Again no KR but on 19-20 degrees of timing A/F was 12.2 (acceptable).

I than bumped up my low octane table from 4200-7000 to 24 degrees. I'll be. Next run 405 rwph everything looked great, still a little rich (no KR), but now 24 degrees of timing.

Bumped the low octane table to 26 degrees. Next pull 412 rwph and 26 degrees of timing.

Why? It seems like my SS is not even reading the high octane fuel table.

Any ideas?

Any help would be appreciated. I am not experienced at LS1 Edit and their is NO local help.

Thanks

David

John02SS

iTrader: (47)

If the pcm sees a bunch of kr is assumes you got some bad gas and drops to the low octane table. As soon as you fill up it goes back to high octane table assuming lots of kr isn't present. BTW, good numbers! NBM is the fastest color anyway!

Bink

No, sorry- this is not accurate info. Here is the actual Octane Scaler info from GMPX Adaptive Knock Scaler info

I believe you can "See" this with the later 6.3 Versions of EFILive. EFILive is light years ahead of Autotap. FWIW.



joel

Navy David SS

iTrader: (13)

Thanks Bink

BUT I am see no KR on the engine run. No ping, nothing.

I understand that the High octane is the "high" end of timing, as to where the Low Octane table is the "lowest" it should go when it see KR; and than recover to high octane as soon as it see no more KR. BUT there is no KR. Not even .anything. 0 .

Why is it not reading the high octane table? As long as there is no KR is there any problem just bumbing up the low octane table.

David

Bink

Pull the PCM fuses wait a minute then replace - this will reset adaptation. Then see if you see high octane timing? Could your engine coolant temps be causing reduced timing. Below ECT of 75*c the PCM pulls timing in the 0.2 grams/cyl region.... at least on an 01 LS6 it does? Let us know your results.

joel

Bink

Here's a better EFILive reference on the High/Low Octane tables.
Here

As GMPX says in the thread you can hold the PCM in the high Octane table by setting the Knock Learn RPM value to an RPM you won't see.


Also GMPX told me to increase my Knock Retard Decay (Knock Fast Recover Rate) by increasing the "Decay vs RPM" values to 128 at all points.



joel

Navy David SS

iTrader: (13)

Thanks again Bink

I set by Knock Learn RPM to 7000, and I can see that this would help.

But Knock retard decay, what would increasing the values to 128 do? Is this the percentage that the retard is actually recovered -- i.e. the trend you noted stated that high at 20 and low at 10, that a lot of times it "averages" the timing based on number in the the decay table. Mine are at present time set all at 53% from 4000-7000. SO in actual term, it would be increase the High Octane by 128% to 25.6 vice lowering it by 53% to 10.6. Right? SO if I just add more timing to the Low Octane to match the High Octane wouldn't this also work?

Sorry about all the dumb *** questions. Still learning this stuff.

David

Bink

My understanding is that the 128 value increases the knock retard recovery rate. After an incident of knock your timing values will recover, to their previous value, more quickly. I'm not sure if 128 is maximum recovery rate - it's easy to check.



joel

Navy David SS

iTrader: (13)

I think I'll try baby step at 7000 on the learn and 70 on the decay for now.

I will be going back to the dyno before I race, I'll down load the new program than. Until then it is set and wait for a race track to open around here

David

MECHAM

iTrader: (4)

wow...very nice thread...very nice