I have a v6 with a terrible exhaust basically i have clogged catalytic converter a exhaust leak and the muffler is basically falling apart lol. so I am going to get it replaced but i want it to sound good a guy quoted me 400 hundred for a new everything but i don't know what size piping he will use. anyway i don't know what size the factory exhaust is but i was thinking of three inch but my friend was revving his bone stock engine at school one day and it sounded so good it was deep and loud. i was just wondering should i get 3 inch exhaust or 4 inch exhaust and if theres much of a difference and is one more expensive than the other any suggestions would be great Thanks

 

Dude. No.

 

what? Are you saying no to puting exhaust on my car it needs it bad

 

their is ti much backpressure from the clogged cat cuasing the engine to stuter at low speeds

 

Sorry, was trying to find a pic of grumpy cat saying something disparaging about large exhausts......

3" is excessive. 4" is full on retarded. Clogged cat? Replace it or run stock size straight pipe in place. Get an aftermarket muffler like a Flowmaster 80 series, and have the tips turn down. It'll be loud, sound good (at idle), and flow better than stock.

 

Dude, no... Flowmasters sound like absolute junk on even a decent running V6. Why you would want to pay $80+ for that noise is beyond me (as it is with the whole fart can thing). There are mufflers out there that cost half as much that sound much better.

OP, there is a thread titled "the best mufflers for V6"... Might want to browse through it if you're determined to put on a full exhaust from the cat back. But you need to replace the cat with a direct fit first.

And, for the love of Pete, do NOT get an exhaust for your V6 with any pipe larger than 2.5". Unless you want to sound like junk.

 

2.5" is as big as you should go. No Flowmasters either, If you want that Chambered sound then go for a Hooker Aerochamber. It won't drone, has a decent idle and sounds great at WOT.

 

if the guy is bending up the ex system himself with a bender use 2.75 inch pipe
the reson being most ex shop benders are crush or kink benders , and were the bends are the pipe size is greatly reduced cause the bender crushes the pipe

 

True but a stock or mild 2.8/3.1 won't out-flow a 2.25" pipe let alone a 2.5".

 

Don't get flowmaster, just like the others said. They sound like crap. I had a dual ex set up with them back when I got my car and it was horrible.

Dynomax sounds good IMO. Ive linked this before but its the only really good sound clip I have of the system. 2 1/2 inch to the muffler, then 2 1/4 out. Also had a magnaflow hi flow cat. Anything over 2 1/2 inch is overkill badly.

 

3" only if you're planning on making a lot of power. 2.5" max I'd say for anything N/A. I like the sound of my OBX exhaust and it's pretty cheap. It is 3" though. Dynomaxes sound really good too.

Totally agree that 4" would be retarded, not to mention expensive. I could be wrong but I believe you would actually lose power through a 4" exhaust because of having zero velocity.

Another thing to consider is the manifolds/y-pipe on the engine. If the y-pipe is smaller than 2.5" there's no way you could make more power with anything larger than 2.5".