BIGGER IS NOT ALWAYS BETTER
With so many exhaust styles and sizes on the market, it’s a headache working out what’s best for your bike. We asked James what works…
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Technical
Bigger really isn’t always better. That’s what I tell my wife anyway. Exhaust bores and diameters are vital to power and smooth running, which is why good exhausts cost a pretty penny. It’s all about exhaust gas speed and flow, speed and flow, otherwise known as fluid dynamics. If you get an old traffic cone (or a new one) and blow through the top, you get a big trombone noise from the bottom. If you do it the other way, what do you get? A soft, wet fart. Exhaust gases work very similarly.
If you have an oversized pipe fitted, it might look great but generally it’ll lose power due to a loss of pressure. When the exhaust valve opens, there’s no pulsing pressure to draw it and help it through the exhaust system. You can also go undersized, and lose performance in a similar way.