Date: Tue, 28 Jun 2011 21:45:34 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: I4 Happenings in turbovans land
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re
typically sees in an I4 gas engine
present in a DV engine, same RPM? Regardless, I think that was part of
the problem in the Tiico exhaust design; bolting the downpipe straight
to the manifold."
I've made a dozen or so TD exhaust systems ..
an exact reproduction of the stock DV system,
only much bigger, and with a glass pack,
and bolted directly to the turbo exhaust outlet.
nary a problem ever.
Diesel is also easier on exhaust than gas is.
that watery acid in cold gas exhaust .
not present at all in diesel.
I suspect that people do not take inspiration from the stock DV exhaust
system.
the very first time I saw the left exhaust mount..
with one rubber mount in a 45 degree plane , fore-aft wise..
and the other rubber mount there vertical and absorbing vibes left- right ..
I could tell they 'tired hard' .
they would not make two rubber mounts in those angles relative to each other
without a reason.
gasoline may vibrate completely differently of course..
and I do not understand why people don't ...........'Do what the
manufacturers do' in conversions.
Many exhaust systems are kinda hacked and home made looking..
even from exhaust shops.
and welding the whole thing into one piece, from turbo to tail pipe ..jeez !
my TD exhaust systems come apart like tinker toys in about 15 minutes max.
on the left end of the glass pack muffler..
I make a plate similar to the DV one there..
but, it has a U-clamp that has two functions..
one it clamps the big "S' pipe to the glass pack muffler..
and it also supports the exhaust there.
I start with volvo exhaust pipes ...and fab up a large pipe that way..
then have it finish welded. Works great. And that's starting with 'real'
automotive mandrel bent exhaust pipe ..and not even expensive at all.
though I'll say 'gas is different' .
so exact comparison to TD isn't really fair.
we'll see.
I will eventually be building a 16V gas exhaust system ..
from the twin outlet manifold..
I'll start with "J" bends that I'll get from my muffler guy who buys them
ready-made to make headers with , or starting with. them ..
like the SVX headers on my site.
btw..
it is *extremely* rare to find a fabricator / exhaust shop who is both an
ordinary exhaust shop and a fabricator ..
my guy can draw up any plate in cad-cam or whatever on his computer..
and wirelessly tell his plasma cutter to cut out the part, or ten of them. I
get many custom parts made that way.
you can make some awesome stuff that way.
he's perhaps the best welder in Oregon or whatever..
I held his titanium mnt bike frame ..that he made..
even with forks on it, it felt like it was going to float away. Immaculate
welds of course.
I think he said $ 400 in materials alone.
On vanagon guy had a weird turbo from a Euro only AAZ Eurovan engine ..
had to make the flange in two layers..
it was a piece of art I must say. Have pics of course.
if only there was more time to post 'em around more.
when my 16V is done..if I ever get to it ..
it'll look factory, and I'll bet it will last just fine.
And it will be tucked up in perfectly, and curve around similar to stock DV.
that S curve ..where it goes down and forward, then turns and comes around
under the left aluminum mount ( like stock DV ) then does a U turn to the
muffler..
it's complex a little, an S curve in more than one plane ...
but it's elegant, and works super well.
just do what the manufacturers do .
and you'll be on the right track.
you'll notice in most cars, the oil pan is the lowest thing in that part of
the car....without exception actually.
to get the engine as low as possible.
( next evolution on that is dry sump of course...so engine is yet lower.
There has always been a need for dry sump for subaru conversions, since
their pans stick down a fat 4 inches or so over what a waterboxer does . )
sure is a lot of fun !
Scott
www.turbovans.com
----- Original Message -----
From: "neil n" <musomuso@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, June 28, 2011 11:04 AM
Subject: Re: I4 Happenings in turbovans land
On Tue, Jun 28, 2011 at 5:28 AM, mark drillock <mdrillock@cox.net> wrote:
> Some people have had good service from their TIICO. I would not say they
> are crap, just that they have a checkered past. I would dare to say the
> same about most any conversion. Exhaust durability issues prevail. The
> conversions improved with time and further development.
Depending on the swap, some might be tempted to find kludgy work
arounds or poorly fabricated parts.
Not to get too far OT, but if one is mentally trying to deal with a
"thousand" things during the swap process, something like an exhaust
system detail(s) can easily get overlooked. This was my experience to
a certain degree but then I "bit off" quite a bit for a 1st time
effort; I had never made an exhaust system before let alone do any
real attempts at welding.
Rhetorical questions: was Tiico exempt from this mind set? What parts
and techniques did they develop in house?
One image I have of the Tiico engine shows the exhaust downpipe flange
bolted straight to the manifold. Yes the DV did this too, but .... are
the exhaust damaging vibrations one typically sees in an I4 gas engine
present in a DV engine, same RPM? Regardless, I think that was part of
the problem in the Tiico exhaust design; bolting the downpipe straight
to the manifold. On the Mk3 (and later?) VW put those flex bushings
between manifold and downpipe flange for a reason as they did with
their "toilet bowl" junction for the single downpipe.
Neil.
--
Neil n
65 kb image Myford Ready For Assembly http://tinyurl.com/64sx4rp
'81 VanaJetta 2.0 "Jaco" http://tubaneil.googlepages.com/
Vanagon VAG Gas I4/VR Swap Google Group:
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
