Flavour

Dual looks cooler imo, but single doesn't look bad

nima_taba

Hmmm I see my mistake...mass flow changes, therefore density changes! My bad

Nima

NZConvertible

No, mass flow cannot change. I think the confusion is coming from comparing a static situation (e.g. gas in a ballon) with a dynamic one (gas flowing through a pipe).
In either case, mass (static) or mass flow (dynamic) does not change when temp does. It’s the volume that changes. Density is mass/volume, so if volume decreases (because temp decreases), then density decreases. But the mass (or mass flow) stays constant.

Josepi

NZ has been right all along...I like sitting back and reading his posts. BTW, I work in a damned library and have access to all kinds of engineering books on fluid/vapor/gaseous dynamics...

It's fun to just pick a topic and go and learn.

But my vote goes for dual. I have two reasons. Flow and appearance. If you have a stock bumper, what the hell are you going to do with the cutout for a second muffler?!

nima_taba

Ok so NZ, you are saying that the volume becomes less....thereby we can say that at any given instant, an imaginary cylinder of gas inside the exhuast tubing (bounded by the circumference of the tubing and a unit length of pipe) weighs X grams near the exhuast manifold.

BUt near the tailpipe, that same mass of gas will not occupy the same volume...it will occupy less volume. Since the circumference hasn't changed...the unit length has changed. In other words...the gas has become more dense, and in order to maintain a conservation of mass inside the pipe (once the flow has started), the gasses exiting the tailpipes do so with a slower velocity than those entering through the exhuast manifold.

I think I got it now.
Nima

Turbo Timmy

OK everyone go read this then come back and discuss... http://www.nsxprime.com/FAQ/Miscella...austtheory.htm

NZConvertible

Nima, YES!

nima_taba

Phew...man you get out of unmiversity for 3 months and forget EVERYTHING!!! (I took all this stuff...and more is coming....hello Mechanical Engineering...)

Nima

PS. Thanks for the help NZ

flubyux2

you know what AZ, **** it... im never one to admit im wrong, but i could go ahead and admit youre right.

just get the goddamn single. its lighter, more efficient, and CHEAPER!!!!

i think im under the impression taht we want to make this car Fast. we can kill 2 birds w/ one exhaust.

Single exhaust flows JUST as well as a dual exhaust from Y pipe, and weighs LESS than it.

benefits:
1. less weight=quicker acceleration. dont downplay weight savings, every little bit helps
2. more power than stock.

its THAT freakin simple. if you WANT to spend the extra cash for a whole other muffler and tip, have unnecessary weight on your car, just to have something occupying that other cut out in the bumper, then by all means, go for it.

Function over form, i say. a single exhaust will do just as good of a job as a dual cat back on ANY nonturbo FC, other than a wild ***, Bridgeport/PP motor, w/ twin side draft carbs, premix fuel, and the works. but, the single exhaust will weigh less.

compare identical vehicles w/ all things the same, the single exhaust FC n/t will out run the cat back dual exhaust FC n/t. not by much, but there will be a winner.

im sorry for even trying to get techinical. its out of place, cuz its an opinion question. NOT a freakin Science fair for us to show off our skills from high school physics classes.

stick a fork in me, im done.

chris

ReZ311

iTrader: (4)

I like the single setup because the Diff., driveshaft, and trans are easier to get to. Weight, yes it is lighter. + It sounds better. i don't like the tinnnny noise of the duals. Yuck. But we all know duals outflow a single, especially after the thorough and educated explanations of NZConvertible =P



But a car with duals will not scare me at a stoplight.

peejay

You ripped me off on the poll!

I was going to vote "Yes".

WilTaylor

yes it looks retarded when you have 2 cutouts and only one pipe. like you lost a muffler down the road or somethin. I have only seen a few rear bumper covers that have one outlet and they are all expensive as hell from JAP land

ReZ311

iTrader: (4)

Patch the other bumper hole if you are repainting you car.

Nothing wrong with JAPAN.

WilTaylor

I love Japan. I love Japanese cars. I do not love spending the small fortune to import parts from Japan. Especially just to prove to myself that it was worth saving the money and getting the less expensive single exhaust. Lets be real guys- IT LOOKS RETARDED.
IMO at least.

WilTaylor

Hey about patching the hole- I never thought o that.. How would you do that with the lip it has, you know what I mean? How it kind of dips down to accent the tip, instead of just a flat line?? I dont know a whole lot about body work, so I am being for real. I had a 85 GSL-SE and I liked the single on the pass side. I personally like the dual on the s4 & s5. But might think differently if someone has decent pics of a shaved bumper.

WilTaylor

oh yeah, and I would love a bumper that exits in the middle similar to a Zonda. actually inside the bumper, lik the "Racing Cars" on GT1, or an old Cuda. If anyone has pics of that please post them(on a 7).

PaulC

Dont forget loving all those hot Japanese women

PaulC

My only complaint about Japanese cars is that the older ones used virtually ZERO rust inhibitors on the metal, the vinyl interiors produce a gass that coats the inside glass, and the plastic bits break from drying out. :P

Other than that no complaints

Greg

Single Looks dope, go with that. Im a N-1 Fan

ReZ311

iTrader: (4)

Fill in the plastic bumper exhaust hole. then smooth it out. piece of cake man.

flubyux2

quit being a girl about it, and complaining that single exhaust looks stupid.

its called Function over Form.

and as far as patching the hole, its a breeze. Body shops use 2 part epoxies for almost Any job. i used to work at a dealer body shop. the brand is called Luxor, and they have like 50 different epoxies:

plastic to plastic
metal to plastic
glass to metal
glass to plastic
metal to metal
glass to glass

many that could remain flexible after curing, or would harden during curing. you could tell it was working, cuz its an exothermic reaction, it would give off heat.

for instance: you know how on old cars, if you try to adjust the rearview mirror to much, it could break away from the windsheild. well the parts stores sell the repair kits that make you use some kinda super glue. well ive used those kits on both my blazer and van, and both failed. however, on my 79 trans am, i used the Glass to metal epoxy, and that bitch is still stuck to the windshield. i think if i tried to take it off now, it would take some glass w/ it.

anyhow, cut out a section from a spare rear bumper cover. then cut out the cut out, so it doesnt have that rolled edge and its just the plastic cover. then splice in your patch that was cut out from the other bumper. use the epoxy for Urethane bumpers which will remain flexible. then sand it down w/ some sand paper, smooth and blend and feather the edges. and paint it. thats basically how a body shop would do it. those epoxies save SOOO much money. its almost like welding w/o heat.

there is a particular 1 seat super car, its hand built out of ALL carbon fiber. its a unibody monocoque design, w/o a frame. the body IS the frame. maybe you ask: how do you weld carbon fiber? how are you going to mount the drivetrain w/o a frame? the put the bastard together w/ GLUE! its just a bonding epoxy, just like what u can use to patch your bumper.

but is it worth the trubble?

chris

WilTaylor

FUNCTION OVER FORM= FOR AN NA FUNCTIONALITY IS MAXIMIZED WITH DUALS.

I STILL LIKE THA DUALS

flubyux2

duals on an NA are only necessary on the most extreme cars. otherwise, on a mild NA, the performance gain is offset by the weight penalty.

Stevo970

****, I love the look off a TT with dual exhuast. Man it gives it a meaner look then a single! Dual Rules man!

ReZ311

iTrader: (4)

Most of you people go by looks. Has anyone ever heard a single catback APEXi custom 3 inch exhaust? Sounds pretty damn swet. Not all tinny and chainsaw like where as the duals are good at imitating if they are loud.

Quite duals are kool though. =)