Phillip K Smith's The Scientific Design of Exhaust and Intake Systems.

http://www.amazon.com/Scientific-Exhaust-Systems-Engineering-Performance/dp/0837603099

Order through: http://wetwesties.type2.com/amazon.html and WetWesties gets a
little bump from Amazon.

Jim

----- Original Message -----
From: "neil N" <musomuso@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, March 27, 2008 8:50 PM
Subject: Re: Vanagon exhaust diameter? + Custom exhaust fabrication
questions.

> 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/