dual exhaust is common on quads with V-twin or 2 cyl configurations.
some people argue that duals are even ideal for a single cylinder application.
On a V-twin it's a great idea, but IMHO on a single cyl it will provide minimal performance gain over a properly fabricated single exhaust.
the whole idea of dual exhaust is for the pipes to crossover into one another and promote scavenging (i.e. the exhaust gases ability to escape the piping). with a proper merge, additional scavenging will actually suck the gases out of the piping for additional power!
yes, you can have duals without this, but without the pipes merging , horsepower is being left on the table.
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