i am going to be making a custom exhaust from the manifolds back. i have a 01 maxima 3.0L i wanted to use 2 inch pipe for the 2 runners and then merge into a 3 inch or maybe 2.75" i want to run 2 straight through mufflers and a centerspun cat what size will give me the best overall power without sacrificing to much low end.

 

is it fo N/A, or FI?

 

Not even that, just what kind of power are you/are you planning on putting down? Some n/a builds can easily benefit from a 3" setup. Others would know more, but I would speculate that anything over 250 whp would probably benefit from a 3" over a 2.5".

 

My car is an 01 se and im planning to keep it for awhile. since it is my everyday driver low and mid range power is important but i also want to be able to really perform on the highway and plan to upgrade other parts of the car as needed. the car has alot of low end power so maybe a 3" would be the right size. Im trying to keep it quiet but as free flowing as possible. While looking for exhaust parts i couldn't seem to find any decent exhaust manifolds/headers for the 00 or 01. Does anyone know of any that will fit the 01. They don't have to match to the y pipe because i will be making my own ypipe and exhaust. thanks for all your help.

 

I would get cattman headers with a y-pip and do a basic catback setup from there for now. If down the road you have the rest of the bolt ons and you are looking for more come back and do the 3" catback idea and tweak other things and/or go with FI. just my 0.02

 

Seeing as it sounds like youre planning on fabbing a lot, I would pass the cattmans(as great as they are) and either find some hotshot or other knockoff long tube headers and do the mods required to fit. Or heck, make some yourself...if you have the time and equipment. Keeping with what size, dont go 3" unless youre making a lot of power, or you will actually see losses in the whp numbers.

 

Is there a place to buy just the flanges to bolt up to the engine? i can fab everythin else but those 2 flanges.

 

The flanges to bolt to the head? spdexhaust has them, I'm sure many other shops have them too.

 

kyle hotshots were only for vq35. 3.0s have the ebay knock off option but requires a bit of work to get them to work, if you have a welder you can do it yourself or pay a shop to do it but at that point your looking at 400-500 just get headers on to fit right.

Loses in whp in a full bolt-on 3.0 has yet to be proven, but we will see come monday

 

2.25" with 3"cutout