Quick exhaust question! Fabbing up my own

[S4evr]

i started to do my own exhaust yesterday, just some preliminary welding cutting and measuring. today im going to start taking my old exhaust off and start the new one. my question is, how much do you think it matters where the muffler is placed? right now mine is underneath me, near the middle of the car. what if i were to place the muffler right near the exhaust tips? any difference in sound, or flow charecteristics?

[Sleeeper X]

I do believe it does matter due to the sound resonating within the straight pipe or pipe. I believe it would be louder as well.

[S4evr]

so it would be louder to place the muffler near the end, rather then in the middle of the car?

[Blue_S4]

yes

[NogaroWonda00]

my s had cat back and the muffler was near the tip like 5 or 6 inches from the tip it wasnt unreasonably loud. im doing a custom exhaust as well now that im doing the k04s. are you doing true dual or 3inch. check out aero turbine mufflers they have some crazy technology in it that makes a vortex which gives you negative back pressure once done ill have some videos

[S4evr]

im doing 3.5" all the way back with a dynatech splitflow muffler. should have it done tomorrow afternoon, will post pics and vids.

[b5s4blk]

im doing 3.5" all the way back with a dynatech splitflow muffler. should have it done tomorrow afternoon, will post pics and vids.

3.5" isnt that a little big? i know 600+ Hp V8's running only 3"

[///M3 TO S4]

3.5" isnt that a little big? i know 600+ Hp V8's running only 3"

tell that to bertwerks who had a FOUR inch in his 12.2 second K03 car.....I'm doing a 4 inch on my K04 car....

[Blue_S4]

there is not such thing as too big when it comes to exhaust....get your facts down

[S4M3]

i started to do my own exhaust yesterday, just some preliminary welding cutting and measuring. today im going to start taking my old exhaust off and start the new one. my question is, how much do you think it matters where the muffler is placed? right now mine is underneath me, near the middle of the car. what if i were to place the muffler right near the exhaust tips? any difference in sound, or flow charecteristics?

I have some Electric cut outs for sale . If u need any for you setup . let me know :)

[S4evr]

think of it this way:

most of the true dual exhaust's use 2.5" tubing. the combined cross sectional area is 9.82", while a single 3.5" has a cross sectional area of 9.62 so infact it is extremely similer to running a dual 2.5" setup, it's just easier, cheaper, and lighter to design a single 3.5"

[S4evr]

I have some Electric cut outs for sale . If u need any for you setup . let me know :)

thanks, but as is it will be plenty loud, and plenty of flow.

[S4evr]

there is not such thing as too big when it comes to exhaust....get your facts down

depends on the application, NA cars need a certain amount of backpressure to produce the maximum amount of power, so too big could infact hurt a NA's performance.

[lil' is 300]

think of it this way:

most of the true dual exhaust's use 2.5" tubing. the combined cross sectional area is 9.82", while a single 3.5" has a cross sectional area of 9.62 so infact it is extremely similer to running a dual 2.5" setup, it's just easier, cheaper, and lighter to design a single 3.5"

99% of all true-duals use 2.25'' tubing (ASP, UUC, etc...). So cross sectional area is actually way less than both 3.5'' and dual 2.5''

And yes, there is no such thing as too big on a turbo car.

[S4evr]

99% of all true-duals use 2.25'' tubing (ASP, UUC, etc...). So cross sectional area is actually way less than both 3.5'' and dual 2.5''

And yes, there is no such thing as too big on a turbo car.

oh snap didnt know that lol

[THICK S4]

DUDE YOU SHOULD RUN NO EXHAUST AT ALL

IT WOULD SOUND NUTS LIKE A JET PLANE

[Jung]

run a faux exhaust... just put tips on it but leave it at the downpipes. less work... i'm a big advocate of half-assing stuff that's not necessary
yeah technically you dont need an exhaust at all on a turbo car once past the turbos. in a 4 cylinder honda or v8 mustang, they need exhausts to put a little backpressure on, as not to lose flow characteristics, and in turn, torque (dont want to lose what's already lacking on the honda). but for our cars, the turbos create all the backpressure you'll ever need, so we can just run straight turbos as exhausts. problem with that is Johnny Law and your elderly (or toyota prius schmuck environmentalist) neighbors will complain about it being LOUD, which it is. We only have them to turn that raw sound of God, into heavenly sounds.
good luck with it, cant wait to hear some clips. always love it when people do a DIY exhaust.
How much did it cost you in tubing? total hours worked on?

[Jayco88]

forgive my ignorance... but why do engines need backpressure? i always thought that backpressure was the enemy because more energy is wasted by pushing the exhaust gases through all the turbos/pipes/cats/mufflers etc.

[S4evr]

im not sure, but there is some gas property that makes the exhaust gas act like a vacuum in NA cars so if the tubing is the right diameter the gases are almost sucked out, however if the tubing is too large you loose that effect. (something like that) that of course doesn't happen with turbo cars because the exhaust is getting pushed out.

[S4evr]

muffler: Dynatech 76-006352 - $98
tubing: (4) 45* bends Dynomax 41429 - $30.69 each
8' 3.5 straight tubing - $30
exhaust tips: Magnaflow 35125 - $35 each

grand total comes to $340.76 shipped

about 4 hours in, should finish tomorrow with another 3-4 hours needed.

[Jayco88]

S4ever let us know how it all turns out.. and if you're able, could you post a sound clip or something?

you just might inspire me to do the same thing.
good luck

[2k1.5blacks4]

I don't run any exhaust after the downpipes and i have them tied up with a coat hanger (lazy need to get exhaust hangers or cut them off after the flex joint) and neither does my brother in his S4. In Alabama there are no emission checks (for now) and I have never had a police man say anything about the noise. There is cab drone especially if you have loose coins or dropped bolts but LOUD PIPES SAVE LIVES. Plus in the south every body and their brother has the exhaust cut off their or its some hunk of junk that never had a exhaust check. People don't really seam as put off by loud vehicles as much down here.

[THICK S4]

S4ever, i saw you in NY the other day, the car sounds like SECKS

Nice job on the exhaust mod, it sounds like 4 planes

[S4evr]

funny, i am living in MA right now and was not in ny yesterday..

exhaust is on, will post pics once i'm home and hopefully i can get a video clip soon!