Jedijody - can you explain how a "tuned pipe" exhaust increases engine horsepower? I see they are long and narrow, which, from what little I understand about mufflers, seems like it would restrict exhaust, and so, allow less air\fuel mixture into the carb. Evidently I'm not correct. Also, would tuned pipes be beneficial to increasing power on any gas or nitro engines, or will some benefit more than others? And from the few I've seen online they're not inexpensive. Thanks.