Exhaust System-- I am replacing..

[mickytrus]

Hello,
I am going to be replacing an exhaust system on
a 91 jetta..... 1.6l...........
Couple of questions....
1.) I am new to volkswagen......
what is up with these C-clips on
the exhaust system at the header pipe
to the exhaust manifold......... Is there
a special tool for their installation....
and should I replace them with new ones..
1a.) I also have an exhaust leak at the exhaust
manifold(not sure where). Is this common?
2.) Did the original exhaust have a resonator?
It is not the turbo... (so no cat)....
3.) where is the best prices for an exhaust...
and do I have to pay alot for that muffler?
I want a good system(that is quiet)
Thanks, Micky..

[zagrot]

there is a special tool for reinstalling the clips; to remove them just pry then off. if you have the facilities you can make a tool from thereaded rod, two nuts, and two pieces of rod that fit in the holes in the clips. drill holes in one end of the rods that the threaded rod will fit through, bend the other end into hooks. to use it put the hooks in the holes and tighten the nuts on the threaded rod untill the clips open up, fit the clpis on the exhaust and loosen one of the nuts. no, you don't have to replace them with new ones.
the factory exhaust has a resonator, it should be just behind the gear shift. before you replace your exhaust check the first joint after the manifold, sometimes the inner pipe will creep forward beyond the slit. if this has happened loosen the clamp and push the pipes back togather and tighten the clamp again.
if you have an exhaust leak and there is no hole in the exhaust pipe or the manifold try replacing the round metal gasket where the manifold and exhaust pipe meet.
if you replace the muffler with an atermarket muffler make sure it is not the type that uses fiberglass packing because it will fill up with carbon.

[mickytrus]

Zag,
I like the clip spreader concept...
Yeah, the local supplier that I use
priced me at about 60 for a resonator
and wanted the vin# for the muffler...
said mst expensive muf was 124.00
60 for header pipe and 16 for tail...
rubber straphangers about 2 each.
My front pipe is rotted at the connector.
The muffler was stainless or aluminum and
the tail pipe cracked of.. The resonator
appears to be ok.. no rust...
Do they fill up with carbon and become
inaffective?
I was figuring on just replacing the
intake and exhaust manifold gaskets
anyway... It is kind of noisy up front.....
Had it on a lift and listened from underneath.

Is there anything I should know about
this?
The stainless steel connector that
connects the headerpipe to the resonator
is that OEM....
Oh, one other thing... the parts
supplier told me that He had no listing
for the header pipe. I had to get one
from the dealer.... He said, it is a 5 speed
and that is why ... if it was Automatic he
could get the pipe... I thought this was
a load of cr@@@p... What are your thoughts..
IF is true.... I mean really, could the pipe be
that different between an automatic and a stick?
thanks for the feedback...
Micky

[zagrot]

not sure about the differences between exhaust pipes for automatic and manual transmission equiped cars because i have not dealt with an automatic vw. maybe you could find a downpipe in good condition at a junkyard. the gasket that i was refering to is called the swivel ring in the haynes manual and looks like a compressed wire cone, but it sounds as if this is not causing the problem, and i doubt that you will need to change the intake and exhaust manifold gaskets unless you are replacing the manifold as well (warpage is not impossible but the gasket should allow for all but a great ammount). every resonator that i have looked inside of has been hollow with a pipe going the whole way through and having equaly spaced holes cut in the inner pipe near the inlet (the chamber volume and size of the holes set the tuned frequency of the resonator). some mufflers use a fiberous packing and must be avoided for a diesel aplication because they will clog.

just had a thought, since you are replacing nearly the entire exhaust you might want to see if you can have one fabricated from a larger pipe. i've heard that the na diesel engines pick up some milage and power from a 2" diameter exhaust. from what i've read there is nothing to be gained by going over 3" unless you have a large turbocharger, and reports from people with that equipment is sketchy (just not common enough to get good information).

[mickytrus]

Thanks! This enlarged exhaust is a great idea.
I am gonna look into this today. I found
a custom bender locally yesterday. I am gonna call
them.
Have you heard of anyone putting a header
inplace of the oem exhaust manifold on a 1.6l diesel.

Do you know how of an increase in power is returned?
and MPG?
Micky

[zagrot]

after helping install a performance oriented ehaust (full deal, header to tail pipe) on my room mate's civic i'd suspect that there are economy gains to be had from putting a header on a vw diesel (the civic saw about 10 mpg average increase, city and highway) i've heard people say tha headers installed on the 1.6 crack from vibration. the water cooled vw performance book that my brother just bought says that even on gasoline models it is wise to install a special front motor mount that restricts the movement of the engine when installing headers, basically it is larger than the stock mount and fills the cup that bolts the the radiator mount whereas the stock one has about 1/4" of space all of the way around. after looking in the 1.6 manifold i can say that it looks like it should not pose a restriction, and it sortof reminds me of a try-Y header, but since the passages are so short i should not be of any use untill well outside of the diesel's rpm range. i recently found a forum that deals heavily in vw diesel modifications but have lost the url. it seems that the larger exhaust is a popular modification and i have wanted to add this to my car for a long time but can't justify replacing it because there is nothing "wrong" with mine if you don't count it's small diameter.

[mickytrus]

Zag,
That is a significant increase in mpg on the civic...pretty cool.
The vibraton thing is an issue.. makes sense.........
This url that you don't remember..... I will try and
google it and see if I can find it.....
Can you give me some clues as to what kind of key words to use.....
ANything will help... IE: diesel , performace , forum???????
I really think I would like to do this.. I just want to do it right.......
If I can find the best aftermarket products, do it myself.......
slap in that motor mount that you mentioned.....etc........
sounds worth it....... the idea of increasing mileage 25%.... possibly...
micky

[zagrot]

yeah, the civic was a surprise for me too. it did not feel much different after the instalation, but about two weeks later my room mate remarked on how much longer a tank of fuel was lasting, well at least after the new toy syndrome wore off and he started driving sensibly again.

i doubt that you will find much in the way of aftermarket performance parts for the diesel engine. i've seen some stuff where exhaust manifolds from gti's were installed, but the writers usually did not provide much information other than "hey, look at what i did."

honestly can't remember the search criteria that i used to find the forum that i made reference to (think i was trying to determine if there is a 16 valve tdi or just a typo in an article that i was reading). if i stumble over that forum again i'll be sure to let you know.

[mickytrus]

Zag, I may have a header...
Could you... if it is not too much truble...
just click a bit for me see what you think.
This guy I called in OR. says,"this".
this is a pic of the header.
***http://www.bosalperformance.com/imag...od/999-776.jpg
**http://www.techtonicstuning.com/
**go to headers link in left frame...
this will be in the large frame on right...part#251.265 (bosal #999776)
**go to exhaust system vw link in left fram
this wiil be in the large frame on right part#253.414f
He says, 1.8L and 1.6L has the same head...
(in terms of exhaust bolt pattern)
I should be able to use this header.. according
to him.... it is an 8V....
Still lookin' for the motor mount.....

that book you brother has.. is it a good book?
sounds pretty good........ Is it worth getting...
what is the title author etc.......
There prices seem competitive.....
If not paying tax then it is shipping....
Thanks,Micky

[zagrot]

the book is titled "Water-Cooled Volkswagen Performance Handbook" by Greg Raven. not bad but not great, fortunately it is not very expensive either.

it looks like the header would fit a diesel head, but i can't assure you that it won't crack (would be a huge waste of money if that happened). maybe if you install it you can make a brace that attaches the bottom part of the manifold to the block.

i'm not sure that a header would make a huge difference (these things already get insane milage anyway). it would be signifigantly cheaper to have the pipes bent up to mate with the stock exhaust manifold (you'll still need that huge flare from a stock downpipe to mate with the manifold).

[mickytrus]

Thanks for the book title...
I will be sure to check it out.

it looks like the header would fit a diesel head, but i can't assure you that it won't crack (would be a huge waste of money if that happened).
Yeah, this is something to worry about.......
FUR SURE!

maybe if you install it you can make a brace that attaches the bottom part of the manifold to the block.
**Yeah, I really want to do the header thing...
the bracket is a great idea..... this will keep it so
the header vibrates with the motor.....
i'm not sure that a header would make a huge difference (these things already get insane milage anyway).
**Yeah, I am curious now.... I would like to see what the over all outcome
will be.....
it would be signifigantly cheaper to have the pipes bent up to mate with the stock exhaust manifold (you'll still need that huge flare from a stock downpipe to mate with the manifold).
This is true........
I got this funny feeling that something is already cracked up there...
the oem exhaust manifold.possibly....
(basing it on the little trouble shooting i have done so far).....
So this is good.... preparation is necessity...
The motor mount we spoke of earlier....
the one under the radiator.....front one..
I want to do this too.........
What am I looking for......
(*&)*&)*&^^^n busy surfing..... here just found this stuff! below 11:30PM est.
Here just editing the existing post I put up earlier...
here are some links... if you could check them out. ...por favor..
what about going with a solid front motor mount??????
or is solid gonna throw too much vibration into the chasis..??????
http://www.bahnbrenner.com/catalog/E...tor_Mount.html
this one even includes j2's 85-92 diesels.....
this next one says that I may need an additional bracket. probably do with both.
though it does say earlier model... 92 is late.
http://www.eiptuning.com/ecomm/prodd...d=E0308003WPNR
Here is another header I found..
I might also be able to buy a premade bracket with it.....
http://www.autotech.com/prod_engine_....htm#mk2header
the mk2 header is for jetta2 but, scroll down mk1 header shows a bracket......
The header is a 421 but up top it joins to 2 pretty quick......
So much to think about.....
THanks! mick

[zagrot]

i would not advise that you use a solid engine mount on anything that you intend to use as daily transportation, and especially not on the car in question. this is something along the lines of what was recomended in the book
http://www.autotech.com/prod_engine_enmnts.htm
but it just occoured to me that i don't know what the front engine mount from a 1990 jetta would look like and the page jumps from mk1 to mk3 so maybe it is possible that mk1 and mk2 use the same hardware.

[zagrot]

The header is a 421 but up top it joins to 2 pretty quick......
So much to think about.....

don't think it matters how soon the four tubes merge into two, but the distance that the joint between the two tubes is from the backside of the exhaust valves determines the header's tuned frequency. if you look closely you'll notice that the next cylinder that will exhaust is always on the other long tube from the one that is currently exhausting. that is the gist of how these things work for four cylinder engines. you can look at a good picture of a header and start with #1 cylinder, #3 will be on the next long branch (#1's exhaust sets up a low pressure wave going to cyl. #3). when #3 is exhausting the next cylinder, #4, will again be on the opposite long branch. and finally #2 is on the oppisite long branch from four. the real question is at what rpm this allows the low pressure wave to reach the next exhausting cylinder's exhaust valve while it is open.

[mickytrus]

Yes, got you on the technicals regarding
exhaust and staggering the way it is welded
to provide maxium flow........
I was looking into the dual outlet manifolds......
I suppose this is another option. I am paranoid
about the header cracking......
It looks like I am going to go with techtonicstuning.com
for my parts......
If I can just summarize with you regarding header cracking prevention.
The motor mounts for a diesel are designed to absorb
more vibration than a gas motor, correct?. Are they softer?
If I was to get heavy duty motormounts...(hd gas motormounts)
this would restrict the (back and forth motion or vibration) that
would be inclined to crack the header,correct?
(maybe just prolong header life before cracking)
and your suggestion.... of a bracket.. to attach to the bottom
of the motor to the header, such that the header and motor
can vibrate "as one" sort of to speak.
These options I just summarized...........
If there is anything you think you can add, please by all means.....
Doing the work is no problem for me... it is the insight........
prevention .... of potential problems down the road............
** Dual outlet Mani would be an improvement....
but how much....... would you say....(guess-timating).
Micky

[zagrot]

i'm not sure if the diesel motor mounts are more firm than the gasoline mounts because i have never done a comparison, but i think i remember reading that they are. the book that i mentioned only made reference to replacing the one on the front of the car, but if the rest are worn out it will probably help to replace them as well. i doubt that anything other than stock will be nessecary for the one at the timing belt and the end of the transmission.

it seems reasonable to say that a brace between the bottom of the header and the block should minimize the chances of the header cracking from engine movement, but i can't say for sure because it is a bit more complicated than the engine just rocking back and forth when you go on the throttle and then let off, though that movement is a considerable ammount and taking measures to avoid it will help the longevity of a header. something else to consider is how well the header is made. if it is made of thin material and exhibits shody workmanship you would probably do well to return it and save yourself some grief later on. if you really want to avoid problems just use the stock manifold, it is tried and true.