What does the ECU do?
The ECU controls 2 things that the engine needs to operate. 1: Fuel (actually a precise Air/fuel mixture), and 2: spark, Which must be delivered at just the exact time.
The fuel is sprayed into the base of the intake runners by a command given to the injectors by the E.C.U. The amount of fuel is determined by how much time the injector is held open. The amount of fuel required is dependent on engine size (displacement), engines design efficiency, engine speed, load, etc. Another important factor is what octane rating the engine is designed to operate on. Economy cars are normally design with lower compression for low octane (cheaper) fuel. A sports car is normally higher compression and will require high octane fuel. The manufacturer must also meet environmental regulations, so they will normally program the vehicles on the conservative side.
With all this in mind and many hours of testing, the factory programs your vehicle with a precise fuel map. And with the help of various sensors on the engines, the ECU makes constant minute corrections while you are driving.
Spark: The spark intensity is determined by the design of the coil, this doesn't vary. However the time at which the spark is delivered is very important. This is called the Ignition timing. The ignition timing is determined also by the E.C.U. And once again dependant on R.P.M. engine load, fuel octane, the timing must constantly vary.
The timing varies according to engine R.P.M. Since fuel does not burn instantly, we must start the fire (spark) before the piston reaches the top of the compression stroke. The higher the R.P.M. the earlier we must start the blaze. In many cases the spark must strike up to 35 degrees before the piston reaches the top of the power stroke. This is because igniting the fuel that early assures us the hottest time of the fire just as the piston is ready to travel down. If you light the fuel too late the heat of the blaze occurs after the piston is further down in the cylinder. Start the fire too early, and the heat of the blaze, tries to drive the piston back, before the piston reaches the top of the power stroke. Since the piston can't go back, and the flame is trying to drive it back. The piston tries to get out of the engine some other way. Maybe out of the side?? So now what you hear is the rattle, of the piston trying to get out of the block, without a door. (and this is called detonation). Detonation is the result of timing too far advanced, too much compression, too much boost, and or too much engine heat.
So with all this in mind, the factory programs the E.C.U. with just the perfect performance timing, however to avoid engine damage warranties, due to people running low octane fuel in a vehicle designed for high octane, the factory will back off of the timing a bit more for an added margin of safety.
This is where the chip tuners come in. These companies will reprogram the fuel and the timing, using the higher octane fuel. Adding a little more fuel, and in some cases removing some, and advancing the ignition timing to the upper limits, FOR the higher octane fuel.
All of this is safe, providing the Chip tuner is using a Dyno, an accurate exhaust/gas analyzer, and you keep your end of the bargain by using the high octane fuel. Typically on a 1.6 to 2.0 liter engine there is a 6-8 HP gain by taking the fuel and timing to the upper limits. Important, purchase your chips from a reputable company that does this for a living, they have the equipment and experience to do this job. Do not buy a chip from a person on the web who only has a lap top and a cable to hook to your E.C.U. Although this person may know his way around his lap top, he is not a car expert. Same goes for other performance items.
Remember a Mini expert is not just a person that owns a mini
The ECU controls 2 things that the engine needs to operate. 1: Fuel (actually a precise Air/fuel mixture), and 2: spark, Which must be delivered at just the exact time.
The fuel is sprayed into the base of the intake runners by a command given to the injectors by the E.C.U. The amount of fuel is determined by how much time the injector is held open. The amount of fuel required is dependent on engine size (displacement), engines design efficiency, engine speed, load, etc. Another important factor is what octane rating the engine is designed to operate on. Economy cars are normally design with lower compression for low octane (cheaper) fuel. A sports car is normally higher compression and will require high octane fuel. The manufacturer must also meet environmental regulations, so they will normally program the vehicles on the conservative side.
With all this in mind and many hours of testing, the factory programs your vehicle with a precise fuel map. And with the help of various sensors on the engines, the ECU makes constant minute corrections while you are driving.
Spark: The spark intensity is determined by the design of the coil, this doesn't vary. However the time at which the spark is delivered is very important. This is called the Ignition timing. The ignition timing is determined also by the E.C.U. And once again dependant on R.P.M. engine load, fuel octane, the timing must constantly vary.
The timing varies according to engine R.P.M. Since fuel does not burn instantly, we must start the fire (spark) before the piston reaches the top of the compression stroke. The higher the R.P.M. the earlier we must start the blaze. In many cases the spark must strike up to 35 degrees before the piston reaches the top of the power stroke. This is because igniting the fuel that early assures us the hottest time of the fire just as the piston is ready to travel down. If you light the fuel too late the heat of the blaze occurs after the piston is further down in the cylinder. Start the fire too early, and the heat of the blaze, tries to drive the piston back, before the piston reaches the top of the power stroke. Since the piston can't go back, and the flame is trying to drive it back. The piston tries to get out of the engine some other way. Maybe out of the side?? So now what you hear is the rattle, of the piston trying to get out of the block, without a door. (and this is called detonation). Detonation is the result of timing too far advanced, too much compression, too much boost, and or too much engine heat.
So with all this in mind, the factory programs the E.C.U. with just the perfect performance timing, however to avoid engine damage warranties, due to people running low octane fuel in a vehicle designed for high octane, the factory will back off of the timing a bit more for an added margin of safety.
This is where the chip tuners come in. These companies will reprogram the fuel and the timing, using the higher octane fuel. Adding a little more fuel, and in some cases removing some, and advancing the ignition timing to the upper limits, FOR the higher octane fuel.
All of this is safe, providing the Chip tuner is using a Dyno, an accurate exhaust/gas analyzer, and you keep your end of the bargain by using the high octane fuel. Typically on a 1.6 to 2.0 liter engine there is a 6-8 HP gain by taking the fuel and timing to the upper limits. Important, purchase your chips from a reputable company that does this for a living, they have the equipment and experience to do this job. Do not buy a chip from a person on the web who only has a lap top and a cable to hook to your E.C.U. Although this person may know his way around his lap top, he is not a car expert. Same goes for other performance items.
Remember a Mini expert is not just a person that owns a mini
