Real Time Tuning Low Octane Spark Table in Speed Density

[meistro]

Hi! 2004 Silverado in speed density. Being in SD, the low octane table is used for spark timing. I can only see the high octane table in the RTT. I tried it anyway with no effect. Am I missing something? How do I get the low octane spark table on the RTT instead of the high octane? I'm running completely open loop, no MAF, no O2 sensors. I used RTT for primary VE and it worked great.

I have the selection with BaseSpark selected. Is this the correct choice? What is HO Spark?

rtt.jpg

[Bill@HPTuners]

What you see in RTT is what is available. You cannot change or add tables.

[meistro]

Thanks Bill. It just occurred to me that HO Spark means high octane spark. I wonder if I choose HO Spark-VE instead of base spark if it will revert it to the low octane table, since that's what the ECU is using when the MAF fails. I'm going to try it.

[meistro]

No luck there.

[Alvin]

The custom OS's are supposed to fix the default to LOW OCTANE in speed density mode. You could make a tune with something really low like 15 total all over in the low octane table and log it to test.

[meistro]

I have been altering the low octane table for a few days and I already know that's the table it's using. It just would have been really great to use RTT on that table. I don't really want to go back to closed loop just so I can do this. The compression is 11:1 and the cam is pretty wild. The engine doesn't like closed loop. Unless there is a way I can un-fail the MAF without the fueling being affected.

[meistro]

It used the HO OCTANE table after I put the MAF FAIL back to 13500 and didn't change anything else. I pretty much just used the RTT to help me see where a few hiccups were. Soon as I felt hiccup and slight sputtering I pressed the plus key a few times. It didn't make much difference while driving but when I copied the table over I could see the few cells that changed, showing me where I needed to add a little more advance. Smoothed out those areas and uploaded the file with the MAF failed again. No more hiccups or stumble. It actually ran pretty much the same with the MAF on and didn't appear to mess with AFR.

[Alvin]

It used the HO OCTANE table after I put the MAF FAIL back to 13500 and didn't change anything else. I pretty much just used the RTT to help me see where a few hiccups were. Soon as I felt hiccup and slight sputtering I pressed the plus key a few times. It didn't make much difference while driving but when I copied the table over I could see the few cells that changed, showing me where I needed to add a little more advance. Smoothed out those areas and uploaded the file with the MAF failed again. No more hiccups or stumble. It actually ran pretty much the same with the MAF on and didn't appear to mess with AFR.

Are you using a MAF enhanced OS? or a 1 bar Speed density. They may only fix the hi/low octane issue with the speed density OS's.

[blindsquirrel]

See how many questions back and forth there has to be when somebody posts a screenshot instead of the actual tune file?