1.8T single exit exhaust

[JoshDub]

I have been looking into exhausts now doing research on sound and built quality, all though I still have a few questions in my mind. The only single exit thread I have been able to find is for a 3.slow from two months ago.

I have gotten a good quote on a 3'' turbo back mandrel bent single exit exhaust with magnaflow muffler. Now I kind of like the single exit idea (yes I know there will be a whole in the bumper, that will be taken care of)

Lets talk about the pros and cons. I have heard that the velocity effects more then the back pressure, is this true? I understand that we need back pressure for the turbo to spool. Wouldn't a Single exit have more pressure along with a less disturbed flow of exhaust gasses? Also Would be saving weight. And a bit of uniqueness factor that other B6's dont have single

Let me here your thoughts. I know im missing something.

/flamesuit on.

[Tohsh]

Less back pressure = more room for the turbo to spool. I was under the impression little to no back pressure is better for the turbo.

[JoshDub]

Then wouldnt it be the best to just leave the back of the turbo open?

[Tohsh]

Yep.

[JoshDub]

*taken from another thread

I put a dump in my exhaust not to far backfrom the DP...... Sounded a lot more beefy and LOUD, but in the end it hurt my performance. (no back pressure and the turbo only spooled a little)

You need mufflers if not for noise control then to keep a little back pressure, and by little, i mean little.

Whats the difference? Im not saying your wrong, just trying to get a better understanding by challenging.

[texasboy21]

I run an open testpipe and the top-end pull is much better. The turbo also spools much quicker.

[old guy]

Check audigeeks for "jeff"

[unknowna4]

Here's a picture of my old car, doesn't answer any of your questions but oh well haha. If you have any questions on what I paid, the setup, or anything lmk.

[mrbacardi35]

^^^what size piping and how much did that run you?

[FORCE_FED_DUB]

4 stroke motors see NO benefit from any amount of backpressure. Flow velocity and scavenging ARE useful to all 4 stroke engines and these are often confused with backpressure by people unfamiliar with the subject.

FWIW: a long while ago, there was a thread on vortex that displayed all sorts of info on the subject; cliffnotes: a single 90* bend creates the minuscule amount of backpressure the turbo likes.

[Jake39454]

A larger downpipe/exhaust will spool the turbo QUICKER and it will produce MORE top end power...

[JoshDub]

Thanks old guy, Ill hit him up. I like that look.

UnknownA4 YGPM

Thanks forcefeddub. So would a single exit provide better velocity? Im talking a full 3" set up. Or should I go bigger?

Thanks DW garage. Is it at the expense of low end power though?

[Jake39454]

Thanks DW garage. Is it at the expense of low end power though?

No, you gain power everywhere...

[FORCE_FED_DUB]

if you are sure you're never going BT, 2.5" is fine (even on some smaller BTs) if you are planning on going to a GT2871R or larger, go with 3". anything larger than that won't be helpful or necessary unless you are going for HUGE power.

[JoshDub]

No, you gain power everywhere...

Okay thats good. I have seen alot of posts where people talk about loosing torque and what not.

Force_fed_dub, I *may* go BT in the future, but not anytime soon. So going with 3'' now wont hurt anything, even if I eventually dont go BT?

[unknowna4]

^^^what size piping and how much did that run you?

3 inch I think (don't really remember it was a few years/cars ago.) Here's a video of it for those interested. Nothing but a magnaflow muffler(which could be taken off, no cats, resonators, ect.) and an open dump for the external wastegate.

http://s16.photobucket.com/albums/b1...rent=Mycar.flv

[FORCE_FED_DUB]

Force_fed_dub, I *may* go BT in the future, but not anytime soon. So going with 3'' now wont hurt anything, even if I eventually dont go BT?

correct, 3" will not hurt performance on the stock turbo the reason to consider 2.5" if you're not going BT is that they are usually not as "boomy" and a tad cheaper. people have made 500+hp on 2.5" exhaust (but would probably make more with a 3")

[anderskt]

i was considering this for my car based on weight savings alone...there is absolutely no need for dual exhaust on 1.8's

[JoshDub]

So it really seems as if there is no downside to going with a single exit?

[unknowna4]

None at all

[JoshDub]

Word, looks like im going single exit!

The gas tank is more on the passanger side of a quattro correct? So I should put the single exit on the drivers side to kinda balance it out?

[B6Lovin]

I put mine on the drivers side so that it looks like every othe single side Audi.... B5's B8's etc. I have 3" catless from the turbo to a single magnaflow muffler with dual tips. My exhaust consists entirely of one pipe - vband at the turbo and two hangers. I'll put up some pics later if you want

[boostedAvant]

That's sweet^ I like that picture of that denim with single exit as well.

[JoshDub]

Post the pics man! I would love to see it.

[poop_on_jdm]

can you buy a rear valence with one exhaust opening? it looks weird leaving one side open. Unless you had big money for super big ass turbo for a rear mount which is sick

[ADCS]

The only cons of 3" vs 2.5" is ground clearance and slight increase in noise.

[B6Lovin]

the euro TDI bumper has one cutout.


see Jeff Lee's car above.
or google TDI B6 A4

[dougyfresh]

If I ever redid my exhaust I would do a single exit on the driver side like Jeff and Daniel and custom mold my S4 rear bumper. It will also cut down on the drone in the cabin of my Avant. Until then, dynomat the entire trunk...

[texasboy21]

can you buy a rear valence with one exhaust opening? it looks weird leaving one side open. Unless you had big money for super big ass turbo for a rear mount which is sick

We will keep the turbos under the hood, thanks

[texasboy21]

I have always wanted to do a single side exit exhaust, but i doubt there is enough room. I would put the exit right behind the passenger side front tire.

[B6Lovin]

my 3" is quieter than my 2.5" was. idk why the hell people keep saying it's louder....

anyways. here's pictures.

[dougyfresh]

/\
aluminized piping or stainless steel?

[B6Lovin]

aluminized. my whole exhaust (muffler and labor included) cost me like 250 or 300

no rust to speak of cept the welds are discolored... but what do you expect?

I suppose I could put some "rust converter" on them and then hit em with a high-heat paint... but im really not that concerned.




that being said - my downpipe is stainless. shawn made that, and it's currently sleeved onto and welded to the rest of the exhaust lol

[Haenszel20v]

is that really like a 7' straight pipe?

[B6Lovin]

is that really like a 7' straight pipe?

basically. can't think of anything simpler or less restrictive short of an open dump. (too loud, even for me...)

do you see a problem with it? I'm a pretty big fan... 2 bolts and a hanger and the whole thing drops loose. (bolt on the muffler hanger, the hanger in the middle, and a bolt at the v-band on the turbo)

[ADCS]

basically. can't think of anything simpler or less restrictive short of an open dump. (too loud, even for me...)

do you see a problem with it? I'm a pretty big fan... 2 bolts and a hanger and the whole thing drops loose. (bolt on the muffler hanger, the hanger in the middle, and a bolt at the v-band on the turbo)

That looks perfect.
I have made a few exhausts before (not for b6) and used a similar approach. It is definetly easier on a lift, I have always done it lying on my back.

No issue using aluminized, it is cheaper and lighter than SS. Easier to weld and more forgiving on your cutting tools (SS is very hard). By the time it takes for aluminized piping to rust out you will have changed setups or sold the car.

[B6Lovin]

That looks perfect.
I have made a few exhausts before (not for b6) and used a similar approach. It is definetly easier on a lift, I have always done it lying on my back.

No issue using aluminized, it is cheaper and lighter than SS. Easier to weld and more forgiving on your cutting tools (SS is very hard). By the time it takes for aluminized piping to rust out you will have changed setups or sold the car.

danke

[Dopefish]

Oh for fucks sake, back pressure and air velocity are two different things... :tard:

[android3000]

vvIs that just an s4 bumper with the right hole patched??

Check audigeeks for "jeff"

[JoshDub]

I think I might be going with SS, I cant remember which he said for sure though. I plan on just patching the left hole and painting the lowers.