i have a 2000 v6 automatic and am going to add 2 1/2 inch flowmaster dual exhaust and a K&N cold air intake and was wondering how much horsepower and torque it would add

 

not much, maybe 10-15 and thats givin you something.if you want more power look into headers, a cold air intake will help your car breathe better, but all the muffler is going to do is add to the sound, 2 1/2 inch is the stock sizing

 

what size exhaust would you recomend to get a good sound and a little bit more power out of it?

 

I would look online at other people who have gotten the exhaust for the 6 cyl. With many vehicles, you will actually lose power due to a reduction in back pressure. Just thought that I would throw that one out there.

 

You can get away with duels on the 3.8 From what many have said its one of the better ways to go. If you are going to run true duels then you will have to remove the stock Y-pipe and cats so you may also gain a little extra right there. alih is right about the headers and is something you should look into.

 

FYI:

to get as fast as a Z28 it will cost you about twice as much as the Z28.

 

how much would it cost to put true dual exhaust on it

 

oh and by the way stock exhaust is 2 1/4
not 2 1/2
and you would have to get it custom and taken to a shop and some of the muffler places wont do it so you might have to hunt around