I have a 9:1 440 in my Charger, I was wondering what gas you guys would run. I guess my choices are 93 (it might even be 92) Sunoco with ethanol, or ethanol-free 90 octane from Fastrac (I am not sure what brand the gas is). It's a street/strip car, it might see track 6-8 times a year or so.

I guess if it doesn't ping, the 90 is fine, right?

Anything else to consider? I obviously would prefer to run the non-ethanol if I can.

Thanks.

Greg

I switched my Valiant from 93 w/10% ethanol to 91 no e and it liked it a lot. I had to take out some jet, it went rich.

At 9:1 you can probably run 87 without a problem and it might even run better.

What would be the theory behind this?

Ethanol is not friendly with older fuel systems as it will deteriorate rubber diaphragms, hoses, Accel. pumps, has a lower boiling point ( think vapor lock), attracts moisture and several other issues including being less efficient (lower MPG).
back in 1987 or so I was visiting Ne. from Calif. and mistakenly filled up with a 5 or 10% ethanol fuel. The car immediately began to run like cr-p and the mileage dropped a reasonable amount. I ran the tank empty as quickly as i could, refilled with normal unleaded and all was back to normal.

With the 93 you can go with a little more timing though. I agree, without ethanol would be better on a carburated fuel system, and if you deal with hot weather, hot starts can be a problem sometimes.

Maybe the 93 with an ethanol conditioner

And yet my 51 Cambridge runs just fine on E10.

More power potential/btu in 87. 93 is harder to burn, which is why you need it with higher compression. Control when the burn happens that way so less likely to detonate. You can get into quench and how the lame smogger 440s don’t have it, but your 9 to 1 should be ok. That’s a whole nother discussion though.

Man you explained that a lot clearer than I would have. Thanks Mike

6-8 times a year
Get that junk outta the garage ! 😁
If thats case run 90 that you czn get at speedway rite around corner From your house
And i blend with 110 . Do you ping when u hammer on it ?
Wheres the timing ?

All my gaskets and hose are modern rated for ethanol , but who knows
Mine slurps 93 $20 bucks a weekend in summer . .
In october i def switch to 90 and blend .
Needles seats stay happier , but even then theyve choked in spring before.

Look at your bowls for residue regardless in April .

You cSn buy race gas on basket rd at BERG

Hi Andy,

I was all set to go on opening day for the first time in a decade, then COVID came along. I am hoping for at least once a month from now through September, that'd be 4 times anyway! Thanks for calling me out on it, ha ha. It's a miracle my junk runs at all.

I sent you a PM.

Greg

If the ethanol crap is easier to get and it runs ok, you could get by running Stabil 360. Use every fill up or two, get a new bottle every two years. Works for me. My stuff has been trouble free, the guy next door refuses to listen each year when I explain to him why his stuff is fubar and how he can stop it.