what exactly happens during detonation?
what exactly happens during detonation?
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From: Rockland County...NY
Car Info: want a WRX
the mixture of fuel and air in the combustion chamber ignites before the spark plug lights....this is kind of a guess but the car wont pull as hard and you will notices a decrease in power...i havent heard of any problems with stock STis ... people have been saying the detonation starts at 400hp(350 maybe?)
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It's a known problem with STis in the 3000-4000 RPM range (before peak horsepower) and Subaru has an ECU reflash available to fix it. There are pages and pages of details and stories on the STi forum on NASIOC.com. It'll sound like a BB bouncing in a metal can.
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In a proper engine setup, you get combustion (therefore Internal Combustion Engine).
During combustion the mixture goes through a slow burn (not really slow, but think of the combustion of a campfire).
During Detonation, the mixture burns before the spark can initiate it. And the burn is not slow, but fast like a dynamite or firework explosion.
This explosion or detonation causes shockwaves inside the combustion chamber. Since these explosions are occurrring so often (about four hundred times a second at idle) it sounds like a harsh rattle.
This also causes a power loss due to the fact that the burn is not pushing the piston, but slamming it, so less power from the burn is transfered into spinning the engine.
different factors cause dotonation (mixture, pressure, temperature, etc.)
tuning the ingition will eliminate the detonation. Hoever most modern engines, especially turbo engines, have knock sensors that will continuously adjust timing of the spark to bring out the most power without causing detonation.
I'm not sure if the WRX has knock sensors or adjusts by another method.
Ok....I'm done.
During combustion the mixture goes through a slow burn (not really slow, but think of the combustion of a campfire).
During Detonation, the mixture burns before the spark can initiate it. And the burn is not slow, but fast like a dynamite or firework explosion.
This explosion or detonation causes shockwaves inside the combustion chamber. Since these explosions are occurrring so often (about four hundred times a second at idle) it sounds like a harsh rattle.
This also causes a power loss due to the fact that the burn is not pushing the piston, but slamming it, so less power from the burn is transfered into spinning the engine.
different factors cause dotonation (mixture, pressure, temperature, etc.)
tuning the ingition will eliminate the detonation. Hoever most modern engines, especially turbo engines, have knock sensors that will continuously adjust timing of the spark to bring out the most power without causing detonation.
I'm not sure if the WRX has knock sensors or adjusts by another method.
Ok....I'm done.
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