ignition timing advance is how many pulses are being fired inside the combustion chamber. more timing advance means more cylinder pressure. at low load cruising, having more advance is ok, but at high load there is more stress on everything, so you want a good balance of timing in relation to the amount of kr. in stock form, every grand prix has kr, but when you start modding you want to get rid of it, so an easy way is to cut timing advance. I've heard some people say anything less than 10* at wot is bad, and others say a minimum of 15* is recommended.
the epa recommended air fuel ratio is 14.7 units of air to 1 unit of fuel because for gasoline engines that is the most efficient ratio. when you start modding and you want more power, a ratio of 11.5 is what I've heard is best for supercharged or turbocharged vehicles.
by definition, boost is the presence of restriction inside an engine. for this reason, too much boost is bad, so just because you have more boost than someone else doesn't mean your car will be faster. more boost increases the amount of pressure inside the combustion chamber, so you can run a smaller pulley and more boost, or a bigger pulley and increase your timing advance. more timing is better because it is always there, while your car is not always making boost. another problem with boost is the by-product of heat. some heat is necessary for combustion, but too much will rob power. the eaton m90 makes a lot of heat, so an intercooler is very effective at making more power. I think I heard for every 10* colder the air is, 1 more horsepower is made. that ratio may not be accurate, but the principle is true. also, more airflow lowers boost, but makes more power because you can drop pulley sizes to increase the boost back up, or add timing advance. another thing to consider is ethanol, methanol or higher octane fuel. ethanol has less energy than gasoline, but has much higher knock resistance, so you can run E85 and a small supercharger pulley. methanol is similar to ethanol, but you can't run your engine on straight methanol, so most people will inject it either straight or in a mixture with water. the methanol raises the octane rating of the fuel being consumed in the combustion chamber, and if mixed with water, the water will evaporate when it gets to the combustion chamber and cool the inside of the chamber. higher octane fuel, like race gas is very simple because you just add it to your gas tank and if you have any knock, to a certain degree, it will go away because the anti knock index of race gas is higher. I have very little kr with the 3.2" pulley I run with 15* of timing advance, and the next time I go to the track I will install a 3.0" pulley, add some race gas, and then give myself some timing advance.
