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double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 11:10 am
by 2DR_GT VDUB
Hi guys

just another quick question. i have the same exhaust setup as the velocitis. a bud if mine says i should change the double pipe tailpiece to a single pipe tailpiece. anyone tell me if it makes a difference if its single or double?

Re: double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 11:14 am
by VW_Mk1_Life
Shouldnt have any effect, its just cosmetic.

Re: double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 11:27 am
by silver-sentinel
Try 3..a little different? lol!

Re: double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 11:32 am
by 2DR_GT VDUB
maybe one that looks like a vw badge at tip will look great

Re: double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 11:47 am
by Jonno
no difference whatsoever

Re: double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 1:35 pm
by VW MAN
nope no difference

Re: double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 2:09 pm
by salo mk2
The double tip gives it that bubbling sound when you floor the throttle.
The single doesnt do that.

Re: double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 2:19 pm
by ironmancdb
But the double tailpiece makes the car look faster :roll: surely this must have an effect on the power of the car :lol:

Re: double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 2:21 pm
by VW MAN
salo mk2 wrote:The double tip gives it that bubbling sound when you floor the throttle.
The single doesnt do that.
bubbling....whistling on idle..

Re: double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 8:10 pm
by dood786
single ftw

Image

Re: double pipe exhaust tailpiece or single pipe?

Posted: Thu Dec 04, 2008 11:12 pm
by 2DR_GT VDUB
@dood what diameter pipe is that?i think i should get a 76mm piece

Re: double pipe exhaust tailpiece or single pipe?

Posted: Fri Dec 05, 2008 7:05 am
by MarcoPolo
ironmancdb wrote:But the double tailpiece makes the car look faster :roll: surely this must have an effect on the power of the car :lol:
:shock:

Re: double pipe exhaust tailpiece or single pipe?

Posted: Fri Dec 05, 2008 7:13 am
by dood786
2DR_GT VDUB wrote:@dood what diameter pipe is that?i think i should get a 76mm piece
thats a 76mm exit tip only

Re: double pipe exhaust tailpiece or single pipe?

Posted: Fri Dec 05, 2008 7:59 am
by ironmancdb
MarcoPolo wrote:
ironmancdb wrote:But the double tailpiece makes the car look faster :roll: surely this must have an effect on the power of the car :lol:
:shock:
hahahahahahahah (just a joke)

Re: double pipe exhaust tailpiece or single pipe?

Posted: Fri Dec 05, 2008 12:36 pm
by OettingerTDi
I received a lecture on this some time ago from good friend, Arno de Graaf of De Graaf Exhausts.

To achieve a double exit there are two ways. One is to have two exits from a common silencer and the other is to split the tailpiece from a single exit.

The double exit type's efficiency is dependent on the design of the silencer, but probably better to go for if you want a double outlet. Get it wrong and it creates a measure of turbulence, which negatively affects performance. A good measure of efficiency is to compare the colour of the insides of the two exhaust tips. If they appear the same colour, :D . Pity we don't have leaded anymore, it would have been easier to see. :?

To change a single oulet to a double usually involves welding on a split tailpiece. The problem here is that you have exhaust gas coming out of the box and being forced to two sides by a V in the pipe. Air gets deflected by the V and bangs into the sides of the two outlets, thereby creating turbulence in the two pipes, giving that "bubbling sound" or pof pof pof sound. This affects the performance negatively, but at least it sounds OK! :wink:

So, which is best? Unless you have a flow bench to test if you have a good silencer or tip, rather keep to reputable brands or exhaust specialists. Remember, more noise always creates the impression that a car appears faster than it is.

For me, a big single outlet works best.

I hope this helps!

Re: double pipe exhaust tailpiece or single pipe?

Posted: Fri Dec 05, 2008 1:15 pm
by 2DR_GT VDUB
Thanks for that TDI. I was just curious in knowing. personally i like the twin. but if it hampers performance in anyway it has to go. :D i already phoned roddy at powerflow bellville for a quoute on a freeflow system.

Re: double pipe exhaust tailpiece or single pipe?

Posted: Fri Dec 05, 2008 2:09 pm
by MarcoPolo
2DR_GT VDUB wrote:Thanks for that TDI. I was just curious in knowing. personally i like the twin. but if it hampers performance in anyway it has to go. :D i already phoned roddy at powerflow bellville for a quoute on a freeflow system.
The performance loss where talking about here is minimal....almost non-existant....If you like a doulbe outlet go for it !

Re: double pipe exhaust tailpiece or single pipe?

Posted: Fri Dec 05, 2008 3:32 pm
by OettingerTDi
Yep, agree, the effect is minimal, but in the quest for more and more power, each small bit helps. Also remember, if the system is not efficient as it could be, you end up paying in fuel consumption. :?

What I tend to do is find someone you can bounce some questions off, you'd be surprised what an exact science exhausts can be. :D

Til later

Re: double pipe exhaust tailpiece or single pipe?

Posted: Fri Dec 05, 2008 3:39 pm
by Howie-WP
2DR_GT VDUB wrote:@dood what diameter pipe is that?i think i should get a 76mm piece
Just listen to what Roddy has to say at Powerflow, he knows his stuff and you can't go wrong. 76mm is way too big. I don't even have that big on my Challenge Car :shock:

Re: double pipe exhaust tailpiece or single pipe?

Posted: Mon Dec 08, 2008 11:21 pm
by vinci
all the problems on my ride aside. id say branch and freeflow was the dumbest thing i ever did to my car....i dont know why? or how, afaik its a wildcat branch, with a pipe from supaquick there in strijdom park and the car just lost its power ever since.... in the beginning i didnt notice as much, and it sounded really cool...

at this time i was using the car at altitude so i didnt notice much, but ever since im back at the coast i can definately feel the difference, it feels dead now :(

i will shortly be slapping on my standard manifold with a standard exhaust system again, ... boyracer days over now, (too much money spent) nothing gained...

Re: double pipe exhaust tailpiece or single pipe?

Posted: Tue Dec 09, 2008 5:00 am
by Torker
I'm keeping the double for a stock look on my Velo - sleeper FTW 8)

Re: double pipe exhaust tailpiece or single pipe?

Posted: Tue Dec 09, 2008 7:00 am
by sixteen10
vinci wrote:all the problems on my ride aside. id say branch and freeflow was the dumbest thing i ever did to my car....i dont know why? or how, afaik its a wildcat branch, with a pipe from supaquick there in strijdom park and the car just lost its power ever since.... in the beginning i didnt notice as much, and it sounded really cool...

at this time i was using the car at altitude so i didnt notice much, but ever since im back at the coast i can definately feel the difference, it feels dead now :(

i will shortly be slapping on my standard manifold with a standard exhaust system again, ... boyracer days over now, (too much money spent) nothing gained...
your first problem was going to supaquick :!:

Re: double pipe exhaust tailpiece or single pipe?

Posted: Tue Dec 09, 2008 8:54 am
by OettingerTDi
Way back a friend of mine rallied a MK1 GTi, circa 1988 / 1989.

He also decided to try a branch manifold made by a well known and reputable concern.

Result, he lost 8bhp on the wheels where it was supposed to allegedly gain.

At the time nothing could beat the factory manifold of the 8 valve motor with a good freeflow exhaust.

It seems that these days a bit of research can save you a lot of agony. There will most certainly always be compromises.

Re: double pipe exhaust tailpiece or single pipe?

Posted: Tue Dec 09, 2008 3:50 pm
by vinci
u know as i get older , i get into the habit of realising how dumb u are when ur young,

these guys at vw obviously did their homework before they built the car the way they did, no yes technology wasnt all that back in those days, but, i am positive that back then they were tryin to squeeze as much power out of the motors as possible...

now 3 years ago when i got my dub i went straight for that b.s. nah, on the carb setup I havent seen powergains from most branches, besides once a jobbie from Viper.. that did the trick well, otherwise no thx...

im glad im seeing someone agree with me on this topic, i thought i was going crazy and imagining powerloss after piping...

Re: double pipe exhaust tailpiece or single pipe?

Posted: Tue Dec 09, 2008 4:50 pm
by 2DR_GT VDUB
This is turning out to be quite an intresting post. i agree with what u saying that out of the factory an exhaust or the whole system was build that way on a specific car for a reason. and that reason is to get the best out of the engine. and i wont disagree with that. now take an aftermarket exhaust system like a powerflow. those exhaust are also uniquely build for the setup u running, for one reason to get the most out of the engine. and ja every racer or guy building a car for power etc will feel terrible after putting on a freeflow and branch just to see that u lost power. but then again u went to supaquick. compare supaquick and powerflow. powerflow spesializes in performance exhaust. exhaust that are custom made to your needs. we will go on on and everybody will have their different opinions, but one thing remains before u find the right exhaust setup for your car u will before hand experiment with different applications. its part of the quest for power. i personnaly have already in a few mnths time experimented with to different types of factory downpipes on my car. i now have the correct downpipe now im just gonna put on freeflow and see what happens.

just my 2c