Significant differnece in octane
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Significant differnece in octane
So does it make significant difference with different octane under the boost ?
Like for example I was supposed to put 93 octane
But let's say I put 87 I would expect some power differnece but will there be any chance that it will blow my engine ?
Like for example I was supposed to put 93 octane
But let's say I put 87 I would expect some power differnece but will there be any chance that it will blow my engine ?
Joined: Jul 2014
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From: Chesterfield VA
Octane is the measure resistance to spontaneous detonation during compression before the point the spark plug fires. This is the same as excessively advancing the timing, the explosion happens too far from top-dead-center and holding the pistol back rather than forcing it down. That's the rock-n-roll version, I'm sure the physics majors will chime in with the detailed science. One or two degrees is important in ignition timing. ECUs handle this these days and can be tuned for specific fuels.
(Shamelessly plagerized from the wiki and emphasis added.)
-- Chuck
Timing advance is required because it takes time to burn the air-fuel mixture. Igniting the mixture before the piston reaches TDC will allow the mixture to fully burn soon after the piston reaches TDC. If the air-fuel mixture is ignited at the correct time, maximum pressure in the cylinder will occur sometime after the piston reaches TDC allowing the ignited mixture to push the piston down the cylinder with the greatest force. Ideally, the time at which the mixture should be fully burnt is about 20 degrees ATDC. This will maximize the engine's power producing potential. If the ignition spark occurs at a position that is too advanced relative to piston position, the rapidly expanding air-fuel mixture can actually push against the piston still moving up, causing knocking (pinging) and possible engine damage. If the spark occurs too retarded relative to the piston position, maximum cylinder pressure will occur after the piston is already traveling too far down the cylinder. This results in lost power, overheating tendencies, high emissions, and unburned fuel.
-- Chuck
Joined: Dec 2009
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From: Miami
yes. read on the Forced induction forum to acclimate yourself with the way everything works i.e: fuel, boost, tuning, supporting mods, etc... it'll help you in the long run. IF your car is tuned on 93 Oct just continue to use 93.
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From: Centreville, Va
Yes. Although, the tuner would likely notice a significant amount of knock even on low boost pulls. If your question is correlated with your other thread, the fact that 87 was in the tank could certainly account for the destruction.
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Starting to doubting myself lol this is how bad is after I blew my engine
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Joined: Apr 2003
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From: Northern KY
Is the tuner saying 87 was in the tank? That could definitely explain why your engine blew. One would think they would notice high knock levels, but as they were tuning on such low boost at the time, they possibly weren't watching it very closely.
