What Octane Should I Run?

[JustA302Gt]

Okay guys, I have a 333 stroker with edelbrock intake, heads, comp cam, and some other goodies. I'm gonna be running around 11.5 : 1 compression. I have been told several different octanes but I would like to check what you guys are running. Can I still run pump gas? I'm in a place where gas is mixed with ethynol everywhere, is that okay? I tend to drag race a bit, but I enjoy driving it on the street. I just want the best performance put of my car. What do y'all recommend the octane I run through my motor?

 

[jrichker]

Use 93 octane with or without ethanol and you should be OK.

Avoid gasoline with lead in it if you are running an EFI engine. Leaded gasoline poisons O2 sensors that the computer uses to figure air/fuel ratios. Some race fuels and all aviation gasoline contain lead as an octane booster.

If you are running a carb and don't have a wide band air/fuel meter, you can run whatever meets the best performance goals of your wallet.

 

[JustA302Gt]

Okay, I have a carbed setup but I have been hearing that I should 100 octane or race gas, but I rrally don't want to spend that much every time I get gas. I understand you gotta pay to play though.

 

[mikestang63]

I'd go with 93 and add some race gas. then check your plugs and listen for pinging. It will also depend on where you set timing at. You can always dial it up at the track and throw some higher octane in it.

 

[JustA302Gt]

I'd go with 93 and add some race gas. then check your plugs and listen for pinging. It will also depend on where you set timing at. You can always dial it up at the track and throw some higher octane in it.

Okay thanks. I wanted to stay away from the ocane booster they sell at walmart, like the cheaper ones. Is there a good race gas mix that you can order that's recommend?

 

[A5literMan]

Depending on the actual compression/ignition timing and cam timing events you may be able to just run 93. 11.5:1cr with aluminum heads aren't necessarily a no go. If you want to be save just ask the local track guys where they get their race fuel and order a 55 gallon barrel. I would think a 50/50 mixture of 100/93 octane would be enough. Less if it's higher octane(112 for example). You can tune/adjust from there(read plugs:listen for pinging-add/subtract timing etc).

 

[JustA302Gt]

Depending on the actual compression/ignition timing and cam timing events you may be able to just run 93. 11.5:1cr with aluminum heads aren't necessarily a no go. If you want to be save just ask the local track guys where they get their race fuel and order a 55 gallon barrel. I would think a 50/50 mixture of 100/93 octane would be enough. Less if it's higher octane(112 for example). You can tune/adjust from there(read plugs:listen for pinging-add/subtract timing etc).

Ok thanks for the help fellas. I'll test it out.

 

[BNAZ]

Okay guys, I have a 333 stroker with edelbrock intake, heads, comp cam, and some other goodies. I'm gonna be running around 11.5 : 1 compression. I have been told several different octanes but I would like to check what you guys are running. Can I still run pump gas? I'm in a place where gas is mixed with ethynol everywhere, is that okay? I tend to drag race a bit, but I enjoy driving it on the street. I just want the best performance put of my car. What do y'all recommend the octane I run through my motor?

I would run Mobil 93 for street use and try different mixes for racing until you hear no pinging. Probably take quite a few runs before your satisfied. Good luck.