Originally posted by 02Denali@Jun 10 2004, 03:46 PM
you have two octane tables in your pcm. this is designed for the times when bad gas,heat or other factors set in. it is to protect the engine.

on a dual octane tune--allen will throw in a performance tune in your low octane table so that with the lower octane fuel you will still have some performance.

then he puts in a bad ass 93 or 91 tune for the high octane table.

if you run high octane fuel it will stay in the high octane table giving you more timing and performance.
if the pcm dtects knock for a certain amount and or period it will switch to the low octane table.a olittle less timing and good stuff but you will still be running good.
Does it look at each start of the engine? Day , week ? PCM reset?

As in how often does it listen for knock? Is it going to knock each start?