[Phunyguy]

you just contradicted yourself - "because you won't have any back pressure" - and "answer to your question is that a more freely flowing exhaust system is going to give you better performance" - i think you mean delta pressure? i found some reading in the technical forum. free flowing exhaust on a smaller diameter pipe is good because the exhaust velocity is higher flowing through it and it will create a vacuum behind it that will help to suck the first short breath of intake air:fuel into the cylinder during intake/exhaust valve overlap. I'm pretty sure this is best for a high revving engine. Back pressure is not a good thing - delta pressure is. Depending on where the pipe splits for the two mufflers will decide performance gains as well. running a true dual exhaust will make you lose performance because of the loss of delta pressure whereas 2 mufflers near the end of the exhaust will not necessarily hurt performance - especially in a high revving engine. In fact - i don't think that it will make much of a difference at all. what will make the biggest difference is the header - and a 4-2-1 header would be the best bet in my most educated guess. anything after that should be more free flowing. Someone please help me out on this - point me in the right direction if I am facing the wrong way.