Okay so yes I have tried search but I would like to present my case here. Working on a 1994 GT with full exhaust and a K*N drop in w/o silencer. I just got home with it, I drove it from my brother -inlaw's house to here ran it as empty as I could, filled it with BP Amoco Ultimate 93 octane and a bottle of STP octane boost and drove around for about a half hour to circulate it all through the system. Noticed no difference (not that I would) but it SEEMED like the exhaust had a slightly different smell to it, but it may be in my head. My neighbor is a major hot rodder and I'm gonna see if he can lend me a timing light and maybe some of his time and see if he can help me bump it on here. Now... IS advancing the timing really worth it? I was told stock base timing is about 10 degrees, and it's common to advance it to 14 degrees. Does 4 degrees base timing really help overall? Assuming I get it to advance right and drive fine will I feel the improvement? I have never really heard spark knock or ping before, so does anyone have a video of it or a sound clip or can describe it well, so that on my test drive, I know what to listen for exactly? Thanks in advance!