fleg1

Wow such a educated response!! Lol

articfriends

iTrader: (1)

Buy a knock gauge and temporarily install it (I am guessing you are carb'd), go out and run it with 93 and check for knock, then run it with 87 and check for knock, if no knock turn timing up slightly until it does knock so you know its actually doing something. There is no clear answer for prem vs 87 as you might be running more timing or a aggressive advance curve. Another OSO'er called me last week, wondered why his buddys 502 efi was showing a certain amt of timing at 4800 on his mefi scanner, also noticed that even though the timing curve looked pretty safe it was triggering some knock events in mid range, after discussion we came to believe at some point someone cranked up the ign base timing in quest for more power or that the premium they were getting was illegally labeled as premium when it was actually lower octane. His buddy actually wanted to run 87 too but no way if its already throwing knock sensor. That would be best way for you to really, safely know, Smitty

fleg1

Thanks Smitty!

MOP

I run 87 running 9:125, I run almost 1 mph slower running 93, Higher octane does not always mean more power! All things considered if properly timed I doubt you will have any issues, 8:75 is not high and should not require 91-93.