Date: Thu, 27 Mar 2008 20:50:46 -0700
Reply-To: neil N <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil N <musomuso@GMAIL.COM>
Subject: Re: Vanagon exhaust diameter? + Custom exhaust fabrication
questions.
In-Reply-To: <0a6301c89082$137daa10$6600a8c0@4BYCY41>
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Thanks for the info Kim. I suspected it would be a poor idea to reduce
the ID of the Jetta pipe down to a Vanagon cat/muffler.
I will stick with a 2" ID on pipes after collector. The collector
itself (Jetta) has 1 5/8" pipes.
The only real technical stumbling block right now, is that the
collector will be shorter than the stock Jetta. The overall length of
the system will likely be shorter than the stock Jetta, so that
technical aspect I have to ignore.
At this point, I'm flying blind in a way. I'm sure I could weld the
parts together, but collector length, well I'm learning. Next thing to
find are some 90 mandrel bent elbows. I was able to save the flange
from the Jetta down pipe, so I'll weld the 90's to that then to the
collector, and so on.
Maybe Mr. Google will yield some info on collector lengths etc.
Neil.
On Thu, Mar 27, 2008 at 8:16 PM, Kim Springer <kimspringer@rcn.com> wrote:
> Neil,
>
> Pay attention to the stock system and consider using the same diameters and
> lengths of pipe.
>
> Exhaust systems are designed for length to the collector, from the collector
> to the end of the exhaust pipe and the diameters of each of these pipes. For
> that matter, the length of the intake is designed to tune the engine as
> well.
>
> I have book on tuning 4 stroke engines and another on engine design. The
> second is extreemly engineering technical, the first has pretty basic
> formulas for designing an exhaust system based on displacement, valve size,
> etc. If anyone is interested, I'll dig it up. In my aircooled days, I used
> the books to compare off the shelf exhaust system and to choose velocity
> stacks for my Weber carbs.
>
> Maybe, for a stock engine, this is overkill, but if you are going to go
> through the process of building a custom system, you might as well enhance
> the system or build like stock.
>
> Kim
>
>
>
>
> ----- Original Message -----
> From: "neil N" <musomuso@GMAIL.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Thursday, March 27, 2008 8:01 AM
> Subject: Vanagon exhaust diameter? + Custom exhaust fabrication questions.
>
>
> > Hi all.
> >
> > I'm gathering parts to fab up the exhaust for my Jetta conversion. My
> plan:
> >
> > Short run of 1 5/8" 90 degree pipes from manifold to collector, then a
> > "J" pipe forward, around, and back to stock Vanagon cat and muffler.
> > OR an aftermarket cat and muffler with 2" inlets/outlets.
> >
> > After the collector, the Jetta is 2" pipe.
> >
> > What is the diameter of exhaust pipe on the Vanagon?
> >
> > Can anyone direct me to a quiet good sounding, good fitting after
> > market muffler?
> >
> > And how "tight" a bend can be made (mandrel bent) on 2" aluminized steel?
> >
> >
> >
> > Thanks!
> >
> > Neil.
> >
> >
> >
> > --
> > Neil Nicholson. 1981 Air Cooled Westfalia - "Jaco"
> >
> > http://web.mac.com/tubaneil
> > http://tubaneil.googlepages.com/
> >
>
--
Neil Nicholson. 1981 Air Cooled Westfalia - "Jaco"
http://web.mac.com/tubaneil
http://tubaneil.googlepages.com/
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