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Re: Performance Guide
there's a good thread in the racing - non specific forum, it's called 10 steps to hot roding. it gives good info on how to release power from a carbed engine. some of those don't apply to an efi car (which, im asuming, is what you are looking for) so ignore anything to do with carburators. I'd post the link but i think AF is being screwy, what with the style change, and not letting me see the threads in the forum.
Basically there's a few ways to increase power:
1) Make the engine breath better. Allow gases to get in and out as quickly and easily as possible. you want good flow so that the engine doesn't have to work as hard to push them out, work that can be used to go fast rather than push gases. you also want the gases to have a high when they enter into and out of the cylender, i'll explain this in the next section.
2) Get more oxygen into the cylender. This is the most common way to increase power. when you stuff more oxygen into the cylender you can put more gas in to burn and make more power. Forced induction forces more air into the cylender so you can burn more fuel. if you don't want to install a turbo or supercharger, you can get a free flowing intake. it will add more air into the engine by making the passage into the cylender easier so the air can flow faster. when it flows faster, it carries more momentum and can thus it will more willingly stuff more of itself into the cylender.
resonance tuning helps this as well. if you know how sound works this will be easy to understand, just in case you don't, ill give you a basic explaation. sound is when air undergoes a compression and decompression (or rarefaction, when the air is less dense), when this happens many times in succession, it creates a sound (so you get a wave made up of high density air followed by low density illustrated like this | | | | |||| | | | | |||| | | | | where the tight lines are high density air). when a valve in the head closes, the air behind it rams into it and gets compressed, it then rebounds and sends a chockwave back through the intake that looks alot like a sound wave. when this hits the end of the intake tube some of the wave bounces back. you want the valve to open exactly when the shockwave hit it so that the dense air enters into the cylender.
Velocity plays a part in power because of something called exhaust gas scavenging. this is when the exhaust gases leave the cylender and the intake valve opens before all the gases are out because the exhaust will leave a low pressure area behind it and suck more air in. resonance tuning applies to exhausts because the same shockwave will be sent back through the exhaust tubing but rather than wanting the dense gas hitting the valve, you want the low pressure hitting the valve so that it sucks the exhaust gases out faster.
Another way to add oxygen is to introduce nitrous oxide into your intake. Nitrous oxide's chemical formula is N2O. air is around 21% oxygen, nitrous oxide is 33% oxygen. when it goes into the cylender there is more oxygen to burn more fuel = more power. nitrous decomposes into nitrogen and oxygen at around 500 degrees. that kind of temperature is more than achieved in the combustion process.
3) increase the efficiency of the engine. This includes increasing the efficiency of the combustion by increasing the compression and releasing more of the BTU's (or joules of heat energy) contained in the fuel. or you can tune your engine. tuning valve timing to get the most air into the cylender, tuning the ignition. you want the spark to fire before the piston reaches top dead center. this is because you want the fuel to start burning so that when the piston reaches tdc the burning gases start pushing down on the piston. you can also remove rotating mass, this allows the engine to use that energy that used to be used to turn something to up the power output. removing friction does pretty much the same thing.
There's more that i can say but i've spent enough time on this, i hope this helped answer your question. if you want even more info, you can personal message me.
If you're looking for parts for your car, think about what is restricting your engine, then try to remove it. if your factory exhaust is restrictive, get a better one, etc.
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