Guess I got what i deserved//exjaust questions?

99.5 a4 1.8t apr 93 octane   

so i was the guy whining that my turbo isnt as loud as stock B6's, passats..etc even though i'm chipped and ....well have a swiss cheese k&n setup(better than nothing). what i forgot to mention is i was really talking about the sound of the turbo starting to spool up at low rpms on just a little throttle. when revved up the engine noise overpowers the sound mostly(this is how it is on the stock B6, passat, and my a6 2.7t). anyways, i dont have that noise.

so i was gettin on the highway and like any true atlanta native i was bringing it up to a merging speed of about 90 in 3rd gear when ...boom....a surge of power and the sound of a ricer from nowhere.
(the flange from the turbo to the cat broke)....guess i got what i deserved didnt i???

cause man that turbo was loud(duh).... Notes:
1. free flowing exhaust on these cars is no gimmick for those who question it.  i was at about 5500 when it broke and she gained very noticeable power. (so the butt dyno confirms the real dyno).

2. it actually had the turbo sound i wanted....low rpm you can hear it start to spool on a little throttle....high rpm.engine sound beat it.(obviously, no exhaust).  so i think the upgrade i want for turbo sound may be in exhaust.(and yes i'll work on intake too, if you read my earlier thread the question was why stock b6's, passats , with virtually same stock airbox have more turbo noise.(so i looked to exhaust....))

now i have the opinion, if you have less than 6 cylinders, keep the engine quiet.(although some 1.8t's i've heard sound surprisingly good). so whats a cheap free flowing exhaust i can put on and not have rice noise?  i can weld if a cheap muffler/resonator helps.

and whats that metal braided 3 inch piece on the exhaust shortly after the cat???????  is it for the metal to expand........or is it part of whats making my (small) turbo quieter than i want it?  someone said replacing the pipe from the cat to the resonator made the turbo whine much louder for some reason, im wondering if its because that metal braided piece was replaced.  thanks

The braided bit is called a flex pipe. It's there so that the engine can vibrate and move around without rattling your exhaust all over the place as well.

oh i'm retarded........i just looked at my other thread and what actually made his turbo louder was the flex pipe being replaced by some universal non oem flex pipe..........i wouldnt mind doing exactly that if someone knows specifically what flex pipe makes the turbo whine louder.

Are you sure it's the flex pipe??? That seems weird. If you replace your cat with a test pipe that would make it louder probably. Also if you put a cone filter on there with a nice heat shield you will hear it a lot better as well.

Josh

THIS IS WHAT THE OTHER GUY SAID IN MY OTHER THREAD

I had a 00 passat and when I got the flex pipe replaced, the turbo bcame very loud. The same thing happenned 2 weeks ago when I got the flex pipe replaced on my 01 a4 TQM. The turbo became very loud. The spool sound is almost annoying now.(but i still like it) I think the sound is due to the flex pipe not being OEM because it was replaced at a regular muffler place. I looked at it and the new flex pipe is a little smaller in diameter than the orignal one. Do you guys think the smaller diameter flex pipe is more restrictive? I told the guy but he insists that it isn't, he has "been doing this for 35 years". What do you guys think? I personally think he's a dumbass.

< Message edited by Hernandez3011 -- 2/18/2008 1:37:07 PM >

So he had only the flex pipe replaced and it was replaced with a smaller one??? That shouldn't make it any louder. Its just a straight pipe with a few ridges on it to allow it to flex. I am not sure how that would make it louder.

Anyone else have any ideas???

Josh

i guess its possible.  like i said there is some difference between my car and b6's, passats where you can hear the turbo spool up at low rpms. i know its bigger but at low rpm's its not pushing much more air, and from what i can tell the airboxes are about the same.(and i'm swiss cheesed)........so the lower rpm turbo whine must be something in the B6 exhaust.

yeah i've run open tp a few times. the car sounds like a turbo diesel and is extremely loud. and you can hear the turbo spool perfectly.

replacing the cat with a tp will make the turbo louder. the rest of the exhaust doesn't have as much of an effect but you can still remove the res and swap the other muffler. but honestly you should get an open air filter first. its cheaper and you can make a custom intake very easily.

can't get away with the test pipe in atlanta. unless theres some real affective way to trick the computer.  no one else knows about the flex pipe?

You can trick the computer using the spark plug non-fouler mod.

Josh

quote:

ORIGINAL: bigrobby

can't get away with the test pipe in atlanta. unless theres some real affective way to trick the computer.  no one else knows about the flex pipe?

do your emissions places test awd cars under load or just hook them up to a computer? if they dont test cars under load you can do the non-fouler mod. if they do, you can get a hfc.

actually my dad is about to open an emissions place and 96 up cars are tested by the computer.  even then, i wouldnt doubt it if would pass, my 4.0 wrangler passed 5 years ago with no cat at all.  they may have gotten stricter now.               so what is this mod and what are the pros and cons of it? cost?

Yes, That was me who said that about the flex pipe. When I had my passat, my flex pipe broke. A non-oem flex pipe was put in as replacement and the turbo spooled a little louder and higher pitched. About two weeks ago, the flex pipe broke on my 2001 A4 TQM. (I've only had this car for a month but the engine is identical to the passat I had, under the hood practically everything looks the same) Anyway, I went to a local muffler place because I was desperate, I had to go to class and I needed my car and it wasn't reaching over 30 MPH. They put in a flex pipe which I noticed was about 1/4'' to 1/2'' smaller in diameter. (Please don’t be offended), but you guys who say it's not can not say for sure because you have never done it. You are only speaking from what you THINK may be true. You can not say it's not true when it happened to my twice.
 
Just sharing with everyone what happened to me............when smaller diameter, non OEM flex pipes were installed on my cars, my turbo got louder.....I didn't want it to, it just did.

i believe it for sure, cause i know exhaust affects that turbo whine alot......but are you sure its because of the diameter of the flex pipe? maybe its just the material. frankly, i'd like to know what exactly was put in there cause i want more whine.

if its tested by the computer it will pass. they used the same method as 5 years ago, they just scan for codes. with the non-fouler you raise the o2 sensor out of the exhaust stream and trick it into reading better. the CEL could come back every once in a while but you'll pass the emission test. its a couple bucks at autozone. or you can get an angle block. there's a guy named Wayne over on vortex who sells them. it works better than the non-fouler in that the CEL doesn't keep coming back every once in a while but its a little more expensive

quote:

ORIGINAL: bigrobby

i believe it for sure, cause i know exhaust affects that turbo whine alot......but are you sure its because of the diameter of the flex pipe? maybe its just the material. frankly, i'd like to know what exactly was put in there cause i want more whine.

the whine becomes louder when you break the flex pipe cause your exhaust is now exiting through there instead of going through the mufflers and out the back. i'm pretty sure there's a flex pipe there cause of engine movement. if there was no flex pipe to absorb the movement of the engine your exhaust could crack.

just replacing the flex pipe isn't really gona make the turbo louder, im still running the stock flex pipe with my techtonics exhaust and ecode tp and you can hear my turbo as clear as day

he was saying the new (non-broken) flex pipe made the turbo louder. and i do know what the flex pipe is now.

then he has super sensitive hearing cuz just changing the flex pipe wont make the turbo louder. 

quote:

ORIGINAL: Hernandez3011
 They put in a flex pipe which I noticed was about 1/4'' to 1/2'' smaller in diameter. (Please don’t be offended), but you guys who say it's not can not say for sure because you have never done it. You are only speaking from what you THINK may be true. You can not say it's not true when it happened to my twice.

1- how did the diam of the flex pipe change? then it wouldn't fit the rest of the exhaust...
2- pretty sure most of us giving feedback (at least me) have swapped the intake, tp, and exhaust before, so we're not talking bout what we THINK is true, but what we experienced

What if the sudden restriction is bottlenecking the sound waves.  Maybe because of that, they are contricting, and some sound waves are exiting the pipe, instead of running down the tube to get muffled by exhaust.

i don't know i'm goin down the wrong path with this anyways. if i'm looking for a little more power with not much more engine sound is high flow cat a place to start?  or are there any cheaper but somewhat quiet high flow mufflers out there?  if not, i'll just deal with it. fun enough for a daily driver.

 

quote:

ORIGINAL: chaos92287

1- how did the diam of the flex pipe change? then it wouldn't fit the rest of the exhaust...
2- pretty sure most of us giving feedback (at least me) have swapped the intake, tp, and exhaust before, so we're not talking bout what we THINK is true, but what we experienced 

 

quote:

ORIGINAL: chaos92287

just replacing the flex pipe isn't really gona make the turbo louder, im still running the stock flex pipe with my techtonics exhaust and ecode tp and you can hear my turbo as clear as day

These two quotes above ^^^^^^^^^^^^^^^^^are exactly what I am talking about you saying a different flex pipe is NOT going to make the turbo louder without knowing for sure. You THINK it won't. Chaos, You are speaking on pure opinion and have no proof to back it up. I can't prove it either but I am 100% sure that this hapenned to me for some reason or another. Also, the piece was smaller in diameter but they "blow" the flex pipe end up to fit the original exhaust diameter. What they do is heat the pipe up and make the end big enough to fit over the stock pipe to make welding easy. Therefore chaos you THINK you know what your talking about but you don't.

Remember, before you post anything be SURE you know what you are saying. People who read these forums make important and sometimes expensive decisions about their cars, based on what they read. Notice, when I said I got my flex pipe changed and it made my turbo louder, I never said it would work for everyone. I am explaning what I have experienced and people can take it as they want. So when I see that you someone says It won't change the turbo's sound, I know they are speaking based on opinion rather than fact. You can read all you want about exhaust systems, turbo compressor and turbine variations, but no one is ever sure how any mechanism will react to a change in it's surrouindings without testing. Just like people who don't beleive HP gains from a chip until they see DYNO results right? I dont want to downtalk anyone, I have a B.S. and almost a masters in Mech. Engineering, as a lot of people on this forums probably do. I know what I may not have the proper turbo and exhaust terminology, but I know testing and raw results are what matters. 

P.S. I think Tommyguns has a very good hypothesis as to why the turbo might be louder on my car. I think he's right

mmmk...you wana be a dick about it. i'm game

quote:

ORIGINAL: Hernandez3011

 

quote:

ORIGINAL: chaos92287

1- how did the diam of the flex pipe change? then it wouldn't fit the rest of the exhaust...
2- pretty sure most of us giving feedback (at least me) have swapped the intake, tp, and exhaust before, so we're not talking bout what we THINK is true, but what we experienced 

 

quote:

ORIGINAL: chaos92287

just replacing the flex pipe isn't really gona make the turbo louder, im still running the stock flex pipe with my techtonics exhaust and ecode tp and you can hear my turbo as clear as day

These two quotes above ^^^^^^^^^^^^^^^^^are exactly what I am talking about you saying a different flex pipe is NOT going to make the turbo louder without knowing for sure. You THINK it won't. Chaos, You are speaking on pure opinion and have no proof to back it up. so let me get this straight, i've changed my exhaust and tp but i'm speaking on opinion? yeah i kept the stock flex cause getting a new one is pointless. an older pipe is gona sound any different than a newer one unless you change the composition or the diameter. I can't prove it either but I am 100% sure that this hapenned to me for some reason or another. Also, the piece was smaller in diameter but they "blow" the flex pipe end up to fit the original exhaust diameter. What they do is heat the pipe up and make the end big enough to fit over the stock pipe to make welding easy. Therefore chaos you THINK you know what your talking about but you don't. well since you failed to mention that part, how was i supposed to know? and what the hell does that even have to do about me knowing what im talking about? and technically they don't have to even heat it, a mandrel bender will have an attachment that can widen the tip of the piping to fit over the stock piece. never heard of someone going through all that trouble to widen a pipe by a fraction of an inch. and there's no welding in the entire 1.8T exhaust. the dp connects to the exaust here- http://www.audiworld.com/tech/pics/eng71_PICT0047.JPG  but i digress...

Remember, before you post anything be SURE you know what you are saying. People who read these forums make important and sometimes expensive decisions about their cars, based on what they read. Notice, when I said I got my flex pipe changed and it made my turbo louder, I never said it would work for everyone.well considering your car is no different than thousands of others out there, it should work for everyone I am explaning what I have experienced and people can take it as they want. So when I see that you someone says It won't change the turbo's sound, I know they are speaking based on opinion rather than fact.your a moron. so none of us have ever done this, just you? and just cause someone disagree's with you its opinion? only your word is fact? hahaha. didn't you just say the previous sentence that it wouldn't work for everyone, and now your contradicting yourself... You can read all you want about exhaust systems, turbo compressor and turbine variations, but no one is ever sure how any mechanism will react to a change in it's surrouindings without testing. Just like people who don't beleive HP gains from a chip until they see DYNO results right? I dont want to downtalk anyone, I have a B.S. and almost a masters in Mech. Engineering, so you don't want to talk down to anyone, and then the very next thing you talk about is your bachelors and "almost" masters in ME? LOL  in as a lot of people on this forums probably do. I know what I may not have the proper turbo and exhaust terminology, but I know testing and raw results are what matters. guess who's swapped their exhaust, intake, and tp and who hasn't? i know the effect each has on the sound of the turbo and engine because i've done them in the past. replacing the dp is barely changing anything at all. changing out the rest of the exhaust (dp back and cat) is changing the sound way more.

P.S. I think Tommyguns has a very good hypothesis as to why the turbo might be louder on my car. I think he's right
i don't. the sounds comes out the back of the exhaust(through the mufflers), not magically through the piping wall. and even if it did, the sound out the back would completely overshadow it. and we are talking about the sound of the turbo for christs sake, which is a lot quieter than the sound of the engine

the fact of the matter is the dp with the flex joint in it is a small portion of the whole exhaust. its simply the start of the cat-back exhaust system. based off what you are saying i could change the diam of the piping in between the res and the back muffler by a 1/4" and also magically hear the turbo louder.

I'm guessing that the quality of metal used by the muffler shop isn't to par with the metal from Audi.  If the metal is an lesser quality and perhaps even thinner wall thinkness, together with a bottleneck effect from a smaller dia., then there is a good chance that the sound waves from the turbo escape the flex section more easily then the rest of the exhaust system.  Yes, you do hear more engine noise out the tail pipe then turbo, but you are talking about to different sounds with too different frequencys.

still dont agree with that. your talking about a quiet sound, already muffled by the cat, possibly making it THROUGH some slightly thinner steel, and your ears picking up the slight difference over the noise of the engine. sure i believe ya