I race a Porsche 356 (racecar) 1620 cc four cylinder engine. I run /1 compression. My Solex carbs (a 2 barrel for each two cylinders) run 160 main jets and 160 air correction jets. I must be close to /1 fuel air mixture because the car runs good, the plugs look good, the exhaust looks good. I’m thinking about experimenting with 112 octane Exxon Oxygenated fuel and I don’t have access to a dyno. If the fuel has 10 percent oxygen I assume I would need 10 percent larger main jets like maybe 175 mains or I guess I could use smaller air correction jets. The fuel I use now is 110 octane race gas non oxygenated.
How should I determine that correct /1 mixture.