Performance modifications are not the fringe businesses that they used to be. Worldwide, specialty performance parts manufacturers total make over a billion US Dollars worth of profits yearly. With cars becoming relatively cheaper, even more accessible to the masses and making more power than ever before, the need to get that slight bit more horsepower out of your engine has always been present. That said, any sort of performance modifications are best left to people who actually understand what they are doing and not to the average roadside mechanic. Also remember, some manufacturers will void your warranty if they find any after market fitments in your car.
The easiest way to get that little extra performance from your car is by adding an aftermarket exhaust. Legally, your car’s catalytic controller should not be tampered with. Not though, since most manufacturers have now started making the catalytic convertor and exhaust header as one unit, the easiest way to add that extra zing to your car is to use a ‘Cat-Back’ exhaust. Essentially, a cat-back replaces the exhaust system after the catalytic convertor for better performance. This usually includes pipes of larger diameters, a larger, straight through muffler and low restriction mufflers. All these additions are also considerably lighter than the stock, manufacturer fitted parts. A well-designed exhaust system will usually add a slight boost in horsepower, a smoother and free revving engine, better mid and high-end power through the rev range and a raspier exhaust note.
A few things to consider while installing a new exhaust system are:
1. The minimum volume of the mufflers has to be a minimum of five times the engine capacity. Therefore, if you have a 1.0-litre engine, the mufflers have to total a minimum of 5.0-litres in overall capacity.
2. The diameter of the pipes should be about 30-50% larger than the stock ones. The larger pipes will allow your engine to breather better thereby resulting in cleaner combustion
3. Always remember to add as much glass wool stuffing as possible into the muffler bodies before final welding and sealing them. This rule though, is only applicable if you are custom fabricating your own exhaust.
4. Avoid large exhaust tips. Not only do they look out of place on smaller cars but are also a magnet for the police who are out to make a quick buck.
5. Always use the best quality of steel pipes, preferably seamless for the best quality fluid flow in the exhaust system.
6. One can also use stainless steel pipes if the car in question is not run regularly. That said, a stainless steel exhaust is more durable and ensures better performance as the metal reacts less to the exhaust gasses. Stainless steel welding though, is more difficult.
Always remember, every single bend in the exhaust system has to be flowing and smooth. Sudden bends of any sort will not only disrupt the flow but the extra back pressure may actually end up ruining your engine.