A single pipe is certainly less expensive than multiple pipes, but it's more than that. For trail use, a single pipe makes better bottom and midrange power than multiple pipes. It is also lighter. You're comparing apples to oranges here. On the trail, it's really not about peak horsepower, it's about a wide powerband, instantaneous acceleration and throttleability. Multiple pipes have a much narrower powerband. They can help your engine make more power because they are tuned for a certain narrow RPM range. Multiple pipes are much better suited to long straightaways and lake racing where you hold the thing pinned for much longer periods of time.
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