Guys sorry for the dumb question but what are some side effects of running higher octane fuel than what the car is tuned for? :bash:
Running higher octane than the tune?
- Thread starter usmcvet02
- Start date
car will run rich :shrug:
no power gains, a good smell, exhaust pipe may turn white on the inside insted of black depending on the fuel, and you wallet will be much lighter. and youll destory your cats (if you still have them) and over time your 02 sensors if you run leaded race fuel.
You might want to look into the burn rate of diffrent race gas. Not sure why everyone thinks race gas will run rich if used and the car is not tuned for it because that is not the case. Some race gases my lean the car out because of a faster burn rate.
sure if were talkin about race gas. But im sayin if hes running 100 and hes tuned for 91 then yea he will run rich.
Thanks for the input guys, I'm actually talking more like running 95octane when tuned for 93.....
then fill it up! it wont do anything. just make your wallet lighter...
Should not notice much difference like other have said thought depending on your spark advance on the 92 tune it may hurt your power the burn cycle might be slower and cost you some power. but i doubt it as thats a tiny octane increase
What does octane have to do with volume of fuel to make it rich? The tune commands x amount of fuel and it doesn't matter if that fuel has octane of 5 or 500, fuel is fuel. The octane is only its resistance to ignition, not how 'concentrated' the fuel is. x amount of fuel is the same regardless of octane.
exactly, but you have to consider burn rate....
If your car is tuned for 93 octane and you put MS109 in it the car will run Rich with no change to the fuel volume / ignition timing commanded. The reason as you mentioned is the burn rate. You will be passing allot more unburnt fuel causing the car to run like a bag of shit. on an NA application you will not notice this as much as you do on a Boost application due to lower ignition timing both base and advanced than that of an NA car.
The if you are talking 10 octane points you wont notice a diff but going from pump gas to race gas with no changes the car will run a richer A/F and burn more gas due to a poor ignition curve for the fuel being run. My Whipple car on C16 on the street tune would run almost a full point richer at WOT and cruse than pump fuel. .
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