Toilet bowl vs 4-2-1 C-clip manifold

[drew <drew@dyermaker.cs.uoguelph.ca>]

I believe the toilet bowl manifold being reffered to here is the 4-1
manifold with CO test pipe found on K-lambda equipped cars from 82 on.
Canadian A1 models only had k-lamda on JH motors from '83 (ie Jetta GLI,
Rabbit GTI, Cabriolet and Scirocco)

The c-lip manifold used on non-k-lambda models actually flows comparably
well with the bolt-on dual outlet, as it to is a 4-2-1 style (according to
Raven in Watercooled Performance handbook.) Early original factory
downpipes on these manifolds were dual pipes that joined together under
the car.  Replacements unfortunately were only a single pipe.

On the Canadian market, the 4-2-1 c-clip manifold made its debut on the
1980 1.6 diesel Rabbit (made in germany.)  US built rabbits and pickups
continued to use this manifold on diesel and non-k-lambda cars (ie all
Canadian exports) through 1984.  I'm unsure as to what Canadian-export
Jettas (made in Germany) used after 1982, although I suspect it may be the
4-2-1 C-clip as well (all of my post 82 Jettas are either Turbo Diesel or
GLIs.)

It's my experience that the 4-2-1 C-clip manifold offers comparable
performance to a 4-2-1 bolt on.  Where the bolt-on really shines is when
it's coupled with a TT downpipe.  I currently run this manifold with a
stock JH downpipe on my Scirocco, and it is worlds of improvement over the
boat-anchor 4-1 manifold.  It also allows the use of the stock downpipe
(may be necessary to trim some of the stock pipe where it sticks out past
the flange, as it will interfere with the divider in the manifold.)

Ideally I would like to find a NOS factory dual-downpipe for this manifold
- as I expect the improvements would be closing in on that of the bolt on
with the TT downpipe.  I may well try to make one up (some day) if I can
find someone to mandrel-bend the downpipes.  I once had such a downpipe
from an 80 Diesel, but it had been mangled with a cutting torch by an
over-enthusiastic wrecker... :(

Drew (84 Wolfsburg with 4-2-1 C-clip manifold)


On Tue, 13 Feb 2001, Ewan Hopkins wrote:

> I presume that, by 'toilet bowl' you mean the c-clamp manifold to downpipe 
> connection. Euro sciroccos changed to the clamp style manifold/downpipe at 
> the end of august '83 production. The downpipe was still dual pipe but I 
> don't know if the manifold was significantly different.
> 
> Ewan Hopkins
> 
> 
> >From: thescirocco@juno.com
> >To: ewanhopkins@hotmail.com
> >CC: scirocco-l@scirocco.org
> >Subject: Re: dual outlet manifold
> >Date: Mon, 12 Feb 2001 13:17:28 -0500
> >
> >On Mon, 12 Feb 2001 16:45:03 -0000 "Ewan Hopkins"
> ><ewanhopkins@hotmail.com> writes:
> > > euro MKIIs certainly had the dual downpipes in '82 - even my
> > > carburated 1.6
> > > auto had one!
> > >
> > > Ewan Hopkins.
> >
> >The 4 into 1, "toilet bowl", exhaust manifold was a North America
> >thing...
> >
> >VW's for Europe, and probably the rest of the world,
> >came with the good dual exhaust manifold with 10mm studs.
> >
> >The last year for the US dual manifold, was '81 for Sciroccos, and '82
> >for Rabbits.
> >
> >The earlier non-O2 manifolds, especially the diesel manifolds are less
> >prone to cracking.
> >
> >Peter
> >'79 Scirocco 16V project car
> >'83 GTI "Caged Rabbit"
> >'84 Scirocco, RD/FF
> >'80, '88 Scirocco rollers


Drew MacPherson, Network Analyst, University of Guelph

drew@dyermaker.cs.uoguelph.ca           |  visit the Massey-Harris page:
http://dyermaker.cs.uoguelph.ca/~drew   |  http://m-h.cs.uoguelph.ca


--
Email LIST problems to: scirocco-l-probs@scirocco.org. To unsubscibe send
"unsubscribe scirocco-l" in the message to majordomo@scirocco.org