[Vwdiesel] Eps device, turbos & exhaust
hillsgrove at adelphia.net
Tue Sep 7 23:15:59 EDT 2004
> Wasn't there some trouble with the epsilonian device as well? was that
> care of?
I dunno, some people had issues with it, I have had mine installed for ~75K
and it has worked just fine. In retrospect, I wonder if the problems had
anything to do with those that had weak or failing MAFs on their A4s?
That means I'm up around 75K Upsoluted miles, too. :-))
>Just built the 2.5" downpipe today for this thing. Sounds like a downspout
>with some supersonic cats stuck in it now.
>Might need a muffler.....
The tail piece of the converter on my '98 Jetta TDI rusted off recently,
flush with the midpipe. It was really quiet, even only having a few feet of
pipe (if that) and the intact converter. When I got a chance to inspect more
closely, I was somewhat dismayed to find that at least a third of the
honeycomb in a band near the outer edge had a thin, continuous layer of
soot - on the *outlet* side. That says to me that it was pretty
significantly plugged. If there was any exhaust flow through there, it would
have blown that fluffy soot right off.
Plugged no more. :-))
What a freakin' mess that was. My son and I looked like we just climbed out
of a chimney by the time we were done - sooty black from head to toe. Got a
case of Popeye arm from swinging the hammer so much, too. We did it with the
converter on the car - I was not, no way, going to mess with the outlet
plate nuts. Best to let sleeping dogs lie. The biggest job was getting the
remnants of the converter outlet pipe out of the midpipe, where it was
broken off flush. That sucked.
Ho-leee crap, so THAT'S where my power went! Uncorked - open pipe out of
the converter, just crawling along at about 1500 rpm with the clutch out on
bare pavement in 1st gear, punching it will break the tires loose until it
hits the rev limiter. *Breathtaking* difference. It did OK before, but
nothing like this. I still run around 18 psi of boost after it settles out,
but it builds up so much quicker, and at lower revs than it ever did before.
Probably spikes up to about 20, then drops to about 16, and wavers around
18, depending on how aggressive you are with the pedal.
It, too, sounded as if there was a jet engine spooling up even when it was
idling. To the floor at ~3500 rpm and at full boost, all you can hear is the
shriek of the turbine noise, slightly drowned out by the rushing of exhaust
through the 50mm outlet pipe. Sounds like an open shop air line, it's even
louder than the muted roar of the exhaust noise. The exhaust is still
quieter like that than my '85 1.6 NA was when the headpipe broke off at the
same spot, though. That thing was deafening. No turbo to take the starch out
of the noise.
That 50mm outlet HAS to go. I have a Techtonics 2 1/2" stainless system
from the cat back, but right at the converter it's necked down from 2 1/2"
OD to 50mm ID. I have it patched up right now with a 1 7/8" OD stuck into
the 50mm ID pipe to quiet it down, but it's not a good fit and it leaks. A
2" OD is just a whisker too big to get into the 50mm ID. I have a manual
pipe stretcher, but it wouldn't do a thing to the stainless pipe.
Looks like my plan of attack now is to find a muffler shop that will sell
me a foot-long piece of 2 1/2" OD stainless that has been expanded to 2 1/2"
ID on one end, then cut off the necked-down section and carefully trim back
the tapered outlet of the converter until the 2 1/2" OD pipe will slid in,
then I can weld it in place. That way, I'll get a full-sized system all the
way back. Also need to get a pipe bent up to replace the rear muffler and
incorporate a downspout, so my blue car doesn't have a black butt.
I am still absolutely amazed at just how much turbine noise there is since
the converter became a hollow shell. I like it!
The Passat I picked up a while ago (but which hasn't made it onto the
road - yet) is another prime candidate to be uncorked. It has very little
power, takes a long time to rev up even in neutral, and you can't hear the
turbo spool at all, plus it goes into limp mode if you try to climb a hill.
Just before I bought it, the turbo shaft snapped and it filled the converter
full of oil while it was trying to run away. It has a fresh rebuilt turbo
now and I've verified that the vacuum lines are installed correctly. I'm
sure the converter has got to be at least partially plugged. I shall see....
Lesson for the day? Turbos LOVE to breathe.
More information about the Vwdiesel