With only 91 in your area and 11.x compression I would invest in Tuner Cat and a AKM cable to cut down the advance a little if it shows knock. I would get the cable ($65) and a laptop now if you don't already have this just to see if your getting knock.

Hal

 

on that note do you know of a site for tunercat files, to tune my car for my cai and longtubes?

 

for the 396? or what?

 

what exactly is this tunercat and what can it do besides help with the gas situation?

 

you can disable your alarm,adjust air intake,tune it to pass emissions, just about everything.

 

FWIW octane booster only works for like .1 - .3 of a point. So 91 octane would become 91.1 octane Also, additives are useless unless you motor actually can benefit from it. In other words, if your 396 is running perfect off 91 octane, anything else you do is a waste of $

 

thanks for the info. i guess i won't do anything different now

 

to verify hysr up there, most octane additives are actually not that good for your motor, and will leave red deposits everywhere. Octane Boost claims a 7 point raise in octane, so that makes 91 octane 91.7 octane - pretty wasteful if you ask me.

About race gas: If your car is running with no knock on pump gas, going to race gas isn't going to do anything but slow you down a bit (it burns slower) unless you tune for it..so if your willing to retune your car when you go to the track and bump the timing up some, by all means go for it. Using leaded race gas will cause bad things to happen (see below)

avgas: most people use 100LL avgas in there car which is 100 Octane, Low Lead...but its only low lead compared to other aviation gasolines. Its still pretty high in lead content compared to pump gas! Running that through your car is a great way to knock your O2 sensors out and do horrid things to your cat if you have one. Heated O2 sensors like on our cars will typically last a bit longer on lead gas (race gas or avgas) than a standard O2 sensor, but they also cost 3 times as much!

if you REALLY REALLY want more octane on a budget, there are a few formulas on www.gnttype.org on how to make your own homebrew octane booster using paint store chemicals (Xylene, Toluene, etc)...look around in the tech section.