It seems so simple at first: Buy a car, bolt on some goodies, go fast. Yet for some reason, it often doesn't work that way. Either you can't decide where to spend your limited funds, or you actually get to raid the speed shop only to find that the car doesn't respond the way you'd hoped. So what then? Give up? Get a night job to buy more parts? Buy a Honda?
The answers are no, no, and, anything but that! Don't sweat it-we've compiled a basic plan to get you from ground zero to a respectable level of performance without freaking out and not getting inside the engine. It's not specific to any one type of car, but the relevant facts are there-you just have to do some additional research to fill in the specifics for your particular machine.
ExhaustThe very first thing we'd recommend improving on any car or truck would be the exhaust system. This is an area where virtually all production-based cars can stand major improvement. Obviously if you're considering a set of headers you should also upgrade your exhaust system, but exhaust upgrades can benefit cars without headers as well. A hard and fast rule is to always eliminate as much of the exhaust restriction as possible while still retaining decent sound-muffling.
First, the basics: If you're running a V-8 engine in a conventional car through a stock single exhaust and you want to make power throughout the rpm range, you need to go with duals. Even a stock small-block will pick up some power throughout the rpm range with a basic system using a pair of decent performance mufflers. Although it's all the rage to put enormous pipes on musclecars today, most small-blocks from the '60s to the '80s breathed into 2-inch systems, and that's what their manifold outlets are sized for. You can step up to 211/44 if your exhaust guy has skills, and they'll work well later on with headers. A 211/42-inch system from stock manifolds will also work, but they'll work even better when you add headers later on. Also keep in mind that most replacement pipes are compression-bent or "crush-bent," meaning the machine that shapes them can't prevent the inside of the bends from collapsing a bit. This can seriously hinder flow in particularly tight bends by reducing the internal cross-sectional flow area-in essence making them smaller inside.
Fortunately, the aftermarket has greatly expanded its offerings for mandrel-bent systems, so that for most popular (and even not-so-popular) cars you can simply buy a kit. You'll still need to have the muffler shop create pipes to connect to your manifolds, but this may be the excuse you've been searching for to get those headers.
As far as tube sizing, dual 3-inch systems are really intended for healthy big-blocks. The rule of diminishing returns definitely applies to exhaust systems, so the gains you got going from a single system to 211/44-inch duals won't be repeated when your 300hp small-block is blowing into 3-inch pipes with race mufflers. A mandrel-bent 211/42-inch system will be more than enough for most street small-blocks. Also remember that any 3-inch system will be loud-very loud.
Selecting mufflers is difficult since the catalog can't tell you what they sound like, although more and more muffler manufacturers are loading sound bites on their Web sites. Another alternative is to scope out appealing tones at cruise nights and shows, and then inquire with car owners to find out what they're using and how satisfied they are. Remember that high-flow, race-oriented mufflers are loud, and that much of that noise will wind up inside the car with you, often as a maddening resonance.