I'd like to upgrade the exhaust on my 2012 Nav. I've read all the posts I can find, and dropped in to a few exhaust places which has resulted in some conflicting information and a few questions that I can't answer.
I've read with interest that the Beaudesert 2.75 system has a 2.5 dump pipe and that they have responded to some guys that "the 2.5 dump doesn't affect performance of the 2.75 system". It seems intuitive to me (but am more than willing to be wrong, I am only guessing), that if the 2.5 dump pipe is the narrowest / most restrictive part of the system, then it will govern the flow through the entire system won't it, and you might as well have 2.5 straight through? A bit like the weakest link in the chain or like water flowing through a pipe of two different sizes. Can anyone tell me one way or another if that is correct?
Now my second question. Two different exhaust / performance places have told me that I can go and get a mandrel bent 3" or 2.5" system with 2.5 dump or I could just get the 2.5 dump, a high flow cat and cut the muffler out for way less dollars and pretty much the same performance gains and EGT reductions. They said that the difference between those two options would be measurable on a dyno but would be insignificant enough that a driver wouldn't notice. Has anyone here taken the cheaper option? What was the result? Even better, has anyone here taken the cheaper option then upgraded to a full system later? Did you observe a performance difference when you upgraded?
Long post I know. Sorry. Thanks for your help.
Brett
I've read with interest that the Beaudesert 2.75 system has a 2.5 dump pipe and that they have responded to some guys that "the 2.5 dump doesn't affect performance of the 2.75 system". It seems intuitive to me (but am more than willing to be wrong, I am only guessing), that if the 2.5 dump pipe is the narrowest / most restrictive part of the system, then it will govern the flow through the entire system won't it, and you might as well have 2.5 straight through? A bit like the weakest link in the chain or like water flowing through a pipe of two different sizes. Can anyone tell me one way or another if that is correct?
Now my second question. Two different exhaust / performance places have told me that I can go and get a mandrel bent 3" or 2.5" system with 2.5 dump or I could just get the 2.5 dump, a high flow cat and cut the muffler out for way less dollars and pretty much the same performance gains and EGT reductions. They said that the difference between those two options would be measurable on a dyno but would be insignificant enough that a driver wouldn't notice. Has anyone here taken the cheaper option? What was the result? Even better, has anyone here taken the cheaper option then upgraded to a full system later? Did you observe a performance difference when you upgraded?
Long post I know. Sorry. Thanks for your help.
Brett
