Helping my kid with a budget Tahoe build a iron 5.3 to 5.7, Long question short,with approx 10.8 compression can this be tuned to run decent on mid grade or regular? We are about to bolt the heads on and having second thought,I fueled up my L86 the other day,premium was $5.75gal =$120 probably more 3 day later.

Hopefully its temporary and premium/gas become more reasonable.Thanks in advance

 

Of course.
Run a TR6 plug and just keep timing low. I've tuned low 11CR 6.0s and 6.2s with 87octane. They don't make much power tho.

 

It would be nice to have 2 tunes or can that be done in one tune with the different octane tables?

 

iirc you can do both since HPTuners has a low octane table and a high octane but I could be misremembering

 

The calibrations have a high and low octane table but that is because it will always use the high octane table until there is a knock present, then it reverts to the low octane table that has less timing it. It also doesn't go to the exact value in the low octane table either, it use a knock learn factor that will interpolate between the 2 values to help bring knock away.

So if the high octane is running 20 degrees then the low octane is running 14 degrees of timing in the same cell and it starts to dip down to 50% knock learn factor, it will run 17 degrees of timing. It will continue to run that 17 degrees of timing even with no knock until the knock learn factor starts to go back to 0%, it takes a little bit of time for the KLF to slow work it's way back and it will add in timing as it works it's way back towards zero. That's just a general idea of what it's doing.

He'd still require two different tunes with two different timing tables if you want to run 87/89 octane in one and 93 in the other if he really wanted to get everything out of the engine.

 

Thanks for taking your time to explain.One last question,could a high octaine tune be programmed into the tow/hall mode,is that a common way to do it? If so would that be the same as have 2 tunes? thanks!

 

No, that wouldn't work.

There are still only two main timing tables. Timing does not change with tow/haul mode active.

 

Thanks @FFDP I knew I had something wrong there

 

Thank you!

 

If you're running Speed Density... with the failed MAF sensor the tune always looks to the low octane table first.