i was wanting to redo the exhaust but wanted to ask what would be better doing the duals or just run 2.5 inch all the way back with one canastier.... any feed back appericated.... also looking for exhaust kit.....

 

What are your plans for power for the car?

 

Single exhaust for the win. Dual adds weight and is just for looks. Call me retarded, but Function > Form IMO.

 

i need acceleration for scca events

 

Oh woops I thought I read "true dual" somewhere in there.

Its all about personal preference. Yes, a single exhaust has the potential to weigh less, but if you prefer the look of the dual exhaust, then you're not really missing out on much weight savings.

 

I've got a single 2.5 inch cat back with a Magnaflow 6" round can 2.5 inch in/out. It sounds wonderful. Duals are just for symmetry. I personally don't care whether my car has two pipes out the back, I just want it to run good.

Edit: I bought all the components from JEGS and had it fabricated. I ended up saving a ton of money because it wasn't sold in a kit, just individual components. (And I have a friend with a welder.)

 

yeah and i can buy a single kit on ebay for cheap

 

i think im going 2.5 straight all the way back with one flowmaster turbo 2.5 in/out

 

I run 2.5in straight all the way to a fart cannon with a silencer. cheapest and sounds decent.

 

Sounds really loud.

 

ah flowmaster = heaven

 

Sounds very exceptionally loud.

 

in deed i want them to know im coming..... would this do the job???

 

Yep. They'll hear you from about 1-2 miles away.

 

Dual exhaust adds more than looks. If you like more controlled exhaust tone (or quieter exhaust), duals are the way to go. It's easier to control the "farty" sound and the tin-i-ness with the air flow split two ways. Not at all saying single can't do the same, I just think duals sound smoother. IMHO

Are you NA or turbo? If you want to be annoying to all those around you, then by all means, run straight back with one canister. Some people like that, I for one, don't.

 

If you're at WOT, then bunnybunny isn't exaggerating as much as you'd think.

If you're turbo then it will be a bit quieter then if you're N/A, but still very loud.

 

i dont want them to hear me 1 or 2 miles away i want a deep growl. maintaining back pressure and gettin gmore touqre. i want a little roar but i dont want to be annoying or annoyed.....

 

Single exhaust with only a muffler will be LOUD. Inside the car, your ears will probably ring haha

 

If you want single on NA, I recommend running a high flow cat, resonator, and muffler. You can skip the resonator if you use an actual chambered muffler and not just glass packs.

 

I ran twin 2.5 inch high flow cats to a 3 inch straight through muffler and after a cruise with the windows down on the freeway my ears would have the slightest ring to them. But honestly, its your choice so go for it! Its not like you can't change it back. The only downside is your neighbors will hate you and cops will target you for anything and everything. Be sure to make a Youtube video of someone recording you driving away down a main street so we can see how long we hear you for.

 

ok thanks guys... lol sounds good

 

There's so much misinformation in these threads.

First, backpressure is ALWAYS bad. Period. This whole "backpressure = torque" BS is nothing but a misunderstanding about the difference between "backpressure" and "velocity".

Second, duel exhaust are NOT just for looks. A dual exhaust is the most practical way of keeping high flow while keeping the noise down. Which is why Mazda went with a dual exhaust in the 2nd gen (look it up, Yamaguchi book).

Third, and this is where we get into personal opinion here, all single exhaust sound like crap and make the car look broken. Especially something like the typical Flowmaster. They are loud, sound farty, and the extra bumper cutout will have people asking "did your other one fall off?". The fact is, you can't keep the noise down and the flow up on a single exhaust without adding a HUGE muffler. Packaging then becomes an issue.

With a turbo car you can get away with a single because the turbo itself is a great muffler. Then use two nice quiet stainless packed resonators and an offset rear muffler.

On an NA, duals will keep it quiet. Keep the same nice dual resonators (I like the Vibrant Ultra Quiet series) and quality straight through rear mufflers. A cat helps immensely.

 

Aaron, am I wrong by saying that back pressure is a good thing in the sense of it being used to open the auxilary ports for us with S4s? Or is there always enough back pressure to open up the actuators?

 

True, the S4 NA uses exhaust backpressure to operate the aux ports. When upgrading the exhaust, it either needs to be restrictive enough to do this or you need to operate them via some other method (air pump, etc.).

 

I ran a large-primary header, high-flow cat and RB cat-back on my old 86 GXL. Power was very good and it did a nice job of actuating the aux ports. We replaced the cat with a resonated pipe and threw on a JIC spec 90 single and it got LOUD!!! It was worth it for racing, since we eliminated over 50lbs of exhaust weight in the process, but I hated it on the street.
I do wonder if the same setup with a single Apex'i WorldSport muffler would be more reasonable, while still providing the power and weight advantages.