Date: Sun, 14 Feb 2010 19:22:17 -0500
Reply-To: Chris S <szpejankowski@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Chris S <szpejankowski@GMAIL.COM>
Subject: Re: Exhaust Design
In-Reply-To: <049801caadb0$f41c86c0$6401a8c0@PROSPERITY>
Content-Type: text/plain; charset=UTF-8
I live for the day you answer a question without simultaneously
bashing WBX and gloating over Subaru. We are all very familar with
the ancient nature of WBX design.
2010/2/14, Scott Daniel - Turbovans <scottdaniel@turbovans.com>:
> Hi All,
> well , that is certainly exotic looking and is bound to help some.
>
> What I would think though is .....
> given the relatively extreme crudeness of the intake runners and plenum,
> is that if you can't get much good air flow going in, getting it out
> downstream of the cylinders isn't going to help very much.
>
> I am talking about that small square hole in the air flow meter that all air
> that enters the engine has to go through, and
> the crudeness of plenum and intake runners, and only one intake valve per
> cylinder , and 'ok' ports.
>
> for comparison ..........and to look at a somewhat similar engine
> ........and aluminum block opposed four , ( just a decade-plus newer in
> design ) like the waterboxer but 'a whole lot more' ..........just look at
> the intake system on a Subaru engine , starting with the 1990 EJ22.
>
> The throttle body is nice and big. The air mass meter obviously has to flow
> better ........since the air does not pass through a small squareish hole ,
> like it does in the waterboxers Air Flow Meter, and there is no flapper
> valve in an air mass meter, like an air flow meter has.
> Then look at the plenum area and intake runners.
> The subaru plenum area is nicely cast into nice, large, 'swooping' cast
> aluminum intake runners.........one nice casting.
> They squeazed in a little more intake runner length by curving the intake
> runners up some, then they turn and go straight down into the heads and have
> 2 intake valves per cylinder. You just look at that shape ...and you know
> there is going to me more air getting into the cylinders than in a wbxr
> engine, by far, is my guess. Inatake runner length is good for low end
> power, more is better in that regard.
> < some modern engines even have two different pathways through the intake
> system....one for low end, one for top end )
>
> You just look at the soobie intake ...and see how much more air is likely to
> flow nicely with those intake runners compared to the
> really...........'industrial grade' , like farm equipment almost
> ,......waterboxer intake set up.
>
> I even have late-night wild plans to fit a subaru intake onto a waterboxer
> engine ....though ........that might be impractical, and not even produce
> that much of an improvement.
>
> There must be bigger air flow meters around that would work.
> There have been attempts to fit an air mass meter to a waterboxer engine
> .....not totally successfully I don't think.
> Besides flow reasons, and air mass meter has no moving parts in it , and is
> thus likely to be far more reliable, than an air flow meter with mechanical
> sweep arm on electectrical contacts. I have said this for years (
> regarding fixing things , especially cars ) ...wherever electrons and
> something mechanical interface - that's a weak spot. Arcing in switch
> contacts would be an example, and the air flow meter sweep contacts are a
> really good example.
> In air mass meters ........in my experience, I've never seen a problem
> with a subaru one. In my 88 740 turbo volvo sedan,
> I have to clean the fine wires in the air flow meter every once in a great
> while. You can even buy 'air mass meter cleaner' in a spray can, like
> electrical contact cleaner, which probably works as well.
>
> anyway ..sorry to get off there...
> but , I would have to say the entire intake area of a waterboxer engine is
> rather restrictive, just eyeballing it.
> and ...don't forget ........
> One of VW's traditional strategies ( not true in late model VW's ...but in
> all air-cooled VW's , and waterboxers too ) .....is to keep it underpowered
> to reduce stress on the somewhat underbuilt engine, to help it last longer,
> at least with stock internal parts.
>
> The exhaust here looks wild and exotic - might as well plumb a turbo into
> it if going to all that trouble !
> .
> and ....I 'bet I could' fit Subaru sequential distributorless ( though I'd
> use a distributor body for a place to mount a cam position sensor ) Fuel
> injection to a waterboxer engine. Can't think of any real reason that
> wouldn't be possible. Those are darn strong and consistent fuel injection
> systems.
>
> Scott
> www.turbovans.com
>
>
> Subject: Re: Exhaust Design
>
>
>> Here's a good read with pics on a tuned system.
>>
>> http://www.thesamba.com/vw/forum/viewtopic.php?t=270833&highlight=exhaust
>>
>>
>> On Sat, Feb 13, 2010 at 10:36 PM, Kim Springer
>> <kimspringer@astound.net>wrote:
>>
>>> Hey listers,
>>>
>>>
>>>
>>> Has anyone ever measured up a stock exhaust system to see where it's
>>> designed to make HP. I assume VW did this a long time ago.
>>>
>>>
>>>
>>> I guess another way to ask this question is: Did the folks making SS
>>> exhaust
>>> systems in a 4-2-1 or 4-1 design improve on what VW designed?
>>>
>>>
>>>
>>> I have a book that helps to design 4-Stroke intake and exhaust system
>>> lengths, inner pipe diameters, etc.
>>>
>>>
>>>
>>> All this talk about hollow cats makes me wonder about the secondary pipe
>>> length. Not that anyone is going to gain 10 HP out of this.just
>>> wondering.
>>>
>>>
>>>
>>> Kim
>>>
>>> 88 Tristar #7 (it's either going to get painted or sold in the next year)
>>>
>
--
Chris S.
Disclaimer: "Death and serious injury may occur"
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