exhaust thoughts

[Tom@Rennsport-1]

Originally Posted by TT Surgeon Tubi street Can't go wrong with Tubi!

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[sharkster]

Originally Posted by cannga

Let me go through the bottom line first: You have to audition with your own ears as internet audio clips are unreliable. Pick reputable, established names and don't try to save money.

There are 3 separate issues:
1. Loudness
2. Character of sound
3. Performance

1. Strictly personal preference, and obviously a critical criteria. Most medium loud systems are not that loud at cruising so cell phone *should* be ok.
I should note that if you start out wanting quiet, there is a chance for regret as you end up wishing for louder (and vice versa of course, but less often I think/speculate). So the advice is to go for the loudest system you think you would tolerate. The "right" loudness makes the car sound so good that you will be willing to sacrifice certain things. One example, I have the Cargraphic Loud, which despite of the name is IMO only medium loud system, which is not as friendly for mundane conversations, but in return it is pure ectasy when I slam on that throttle. So I readily and willingly take the exchange.

2. Again, obviously another critical criteria and again a matter of strict personal pref. One example of 2 very good and popular systems that people love: Tubi and Cargraphic. The Tubi (at least the first generation, there are now second gen Tubi's that I've not listened to) does not have as much low frequency rumbling as Cargraphic. Tubi is also more quiet. So if that low frequency rumbling and loudness are not important to your taste, then Tubi is the one.
Once again, if I have not said so , let me repeat: if possible, you must try to listen with your own ears if you are serious about this.

3. An after market exhaust is extremely beneficial for an ECU tune because it reduces back pressure, but by itself, don't expect much that you could "feel" as far as true power. All I felt after installing the Cargraphic is that the system seemingly pools up faster. No study to prove one way or another. There also have been anecdotal reports of some systems actually feel weaker (less torque) in the low end, so I actually felt extremely lucky that my car felt the same!

For Convertibles, 3 most oft mentioned systems are: Tubi, Milltek, and Cargraphic Quiet, mainly I believe because they are more quiet than others. That said, there are people who are happy with FVD and Cargraphic Loud, again pointing the fact that this is strictly a matter of personal preference.

While we are on this topic, I should also point out that ECU mods *could* and do make any given exhaust system louder and shift it to a more stressful, higher frequency sound, and this varies from system to system. For a milder example of this, push the Sport system in your car and listen to what it does to the sound. An ECU tune will be similar in the change in character, except more so in intensity.

When you audition, keep in mind the car sounds totally different whether you're inside or out. While outside sound is more important for showing of, inside sound is vastly more important for obvious reasons.

Click on the link in my signature to see my review of Cargraphic and detailed description of its "character" (basically, menacing, car shaking (I LOVE this!), low rumbling at low rpm, crunchy sound at mid rpm, and an absolute scream at high rpm). Surprisingly, I've become addicted to this sound and it's one of the highlights of my driving experience. I did not expect this addiction when I bought it.

Great post Can. +1

Guys listen to one in person if you can and always remember cheaper doesn't mean better either.

[Leonenglewood]

i still dont know what to go with i think i like cargraphic and awe
i listened to cargraphic and my mouth hit the f---ing pavement
but still didnt get to hear the awe
is there any runs going on this week in nj

[996TTer]

Originally Posted by Halo

This is my EVERYDAY Driver "highway" most. I want to use my Cell Phone for my 2 hour drives. So I would like to find a nice quiet exhaust for the TIP that has 200 cell cats and good PERFORMANCE..


Thoughts?

FVD!!

Read this:
The search in finally over, exhaust & 997TT cab & .

[cannga]

Tom and Alex, thanks. It's good to have seasoned pro's agree with my rambling. BTW, I tried without success to get Cargraphic US Distributor to change that unfortunate and very bad naming system that uses the word LOUD to describe this medium loud Cargraphic system. I think they scare customers away, but what do I know anyhow.

Hello Leoneglewood, AWE is another excellent exhaust and is used by many here, including my car advisors "eclou" and "Gotboost?." Loudness is about same as Cargraphic Loud. It has a very lovely low frequency rumbling. The character of sound is more continuous, as opposed to Cargraphic's staccato nature.

You might want to consider taking a drive to AWE and take a listen. The more systems you listen, the more you will have an idea of what you like/dislike.
In addition, I hold the guys at AWE (and *some* other pro's here ) in highest regard. I think it would be tremendous fun to come and visit their shop and see & learn all the fun things they have there, regardless of whether you are going to get their exhaust system.

[Leonenglewood]

i think i may do that thx cannga

[TT Surgeon]

If you're near the city, have a listen to my FVD.

[Leonenglewood]

thx everyone i think im going to meet up with justin and listen to his fvd.
we should go for a nice run on sunday for lunch with some 997 tt's that would be fun!!!!!!!!!!

[raclaims]

Bring it on...you'll love it...people lose their minds when they hear it...

[Rhonda@FVD]

Cannaga,

With all due respect, the distance that the exhaust has to travel from the single exit is far greater with our systems than hitting a wall which is split into 2 like the picture below. In the picture below the exiting exhaust must travel 2 inches or so before being slammed into a wall and funneled out of 2 exit's. The flow out of our tips allow's the exhaust travel to flow far more freely and does not build as much backpressure. So flow restriction is FAR less with the FVD system. Would you agree?

[TT Surgeon]

The FVD is the best system out there for a coupe imo.

[cannga]

Hi Rhonda,

Before I answer, let me post this interesting article on exhaust system. The article has a picture of the internal of a muffler that I think will be relevant to our discussion. After that we could discuss the question as I would like to learn from you too.

http://auto.howstuffworks.com/muffler1.htm

­How Can You Cancel Out Sound?

The key thing about sound waves is that the result at your ear is the sum of all the sound waves hitting your ear at that time. If you are listening to a band, even though you may hear several distinct sources of sound, the pressure waves hitting your ear drum all add together, so your ear drum only feels one pressure at any given moment.

Now comes the cool part: It is possible to produce a sound wave that is exactly the opposite of another wave. This is the basis for those noise-canceling headphones you may have seen. Take a look at the figure below. The wave on top and the second wave are both pure tones. If the two waves are in phase, they add up to a wave with the same frequency but twice the amplitude. This is called constructive interference. But, if they are exactly out of phase, they add up to zero. This is called destructive interference. At the time when the first wave is at its maximum pressure, the second wave is at its minimum. If both of these waves hit your ear drum at the same time, you would not hear anything because the two waves always add up to zero.


How sound waves add and subtract


In the next section, we'll see how the muffler is designed to create waves that cause as much destructive interference as possible.

Inside a Muffler
Located inside the muffler is a set of tubes. These tubes are designed to create reflected waves that interfere with each other or cancel each other out. Take a look at the inside of this muffler:



he exhaust gases and the sound waves enter through the center tube. They bounce off the back wall of the muffler and e reflected through a hole into the main body of the muffler. They pass through a set of holes into another chamber, where they turn and go out the last pipe and leave the muffler.
A chamber called a resonator is connected to the first chamber by a hole. The resonator contains a specific volume of air and has a specific length that is calculated to produce a wave that cancels out a certain frequency of sound. How does this happen? Let's take a closer look ...

The Resonator
When a wave hits the hole, part of it continues into the chamber and part of it is reflected. The wave travels through the chamber, hits the back wall of the muffler and bounces back out of the hole. The length of this chamber is calculated so that this wave leaves the resonator chamber just after the next wave reflects off the outside of the chamber. Ideally, the high-pressure part of the wave that came from the chamber will line up with the low-pressure part of the wave that was reflected off the outside of the chamber wall, and the two waves will cancel each other out.

The animation below shows how the resonator works in a simplified muffler. (Please go to web site, animation doesn't go through.)

[C4SxM5]

op, sent u a pm concerning a USED miltek system if u r still in the market.

[cannga]

Originally Posted by Rhonda@FVD

Cannaga,

With all due respect, the distance that the exhaust has to travel from the single exit is far greater with our systems than hitting a wall which is split into 2 like the picture below. In the picture below the exiting exhaust must travel 2 inches or so before being slammed into a wall and funneled out of 2 exit's. The flow out of our tips allow's the exhaust travel to flow far more freely and does not build as much backpressure. So flow restriction is FAR less with the FVD system. Would you agree?

First let me stress again I think FVD is an extremely compelling package. The sound seems to be fantastic from users' reports, system obviously is of very high quality, and the cost quite competitive.

Having said that and having studied exhaust system studiously , I do think it's probably not a good idea to proclaim that FVD Turbo exhaust alone has a "true quad tip". At best the claim is controversial, at worst it's incorrect. Sell your system on true merits, not on this very questionable claim. And if you are to ask FVD Germany, I think they would agree with me.

First, as mentioned above, by definition FVD Turbo is just as "fake" as any other because there is only ONE single opening that then splits, in a fake fashion, to a double. My 2 pictures above illustrate this:

Real opening, (FVD GT2):



Fake opening (FVD Turbo):



Also, back pressure created in the exhaust system is proximal to the opening you mention, in the muffler and catalyst. Where you are at the VERY distal exit the pressure is near atmospheric and the pressure drop at best negligible over a few inches of piping. I am afraid you are using strong words such as "far greater," "slammed into," etc., to describe a non-existing issue.

Below is a picture of a system I am familiar with, Cargraphic. I did not look until now but the Cargraphic actually has LESS piping to travel before it opens to air. Regardless, out at this distal point, I really think it's a non issue. Unless you have numbers to prove me wrong.
(BTW, as for "plumbing size," note the huge size of the conduit between the cat and the muffler of the Cargraphic system.)

At any rate, I have this feeling the FVD exhaust is going to sell very well. Great name & quality, great price, great sound? Congrats. I actually am curious enough to think about a live audition!

[handdoc]

great technical info from cannga

no one as a user probably has as much experience with these systems as TT Surgeon, who is currently running an FVD on his coupe, but prior to that had a Tubi Street that he thought was awesome with no drone

bottom line, you need to "hear" them and buy what sound you like...don't expect to notice 20hp by your seat on a 480hp car...all meaningless unless you are doing an ecu tune...it is personal preference re the sound

try to hear systems in person because the you tube clips dont do things justice

good luck