Date: Tue, 9 Nov 2004 12:56:57 EST
Reply-To: FrankGRUN@AOL.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Frank Grunthaner <FrankGRUN@AOL.COM>
Subject: Frank G.'s TDI instrument cluster - Details and Comments
Content-Type: text/plain; charset="US-ASCII"
In a message dated 11/9/04 7:38:18 AM, sergelap@TELUS.NET writes:
> If you are around Frank, first thumbs up for your TDI instrument cluster.
> Beautiful work, but...what's your plan for the interference with the
> brake master cyl./fluid reservoir?
>
>
Serge,
Recently, I'm lurking and only post when sufficiently stimulated or want to
share new results. The press of lab and field work along with minimal typing
skills have limited those posts. I was quite pleased with how the cluster turned
out and very glad that Alistair was able to post the photos on his excellent
web site. So for a few details:
On the master cylinder reservoir interference issue ... it was in the way and
I wanted to maintain the visual angles, so I took it out! I then used a
master cylinder reservoir from a '90's Mazda pickup. It comes (from your local P&P
yard) with a remote mounting bracket. I rotated it so the long axis is
parallel to the windshield long axis. It comes with a built-in level sensor that I
wired into the VW harness. I can't remember if the vanagon originally came with
the level sensor built in of if I added it to the vanagon reservoir and modded
the harness years ago. For the inlet lines to master cylinder, I believe I
used the plastic barb adaptors from a Super Beetle. I use an inline T to tap off
the clutch feed. I mounted the reservoir in the same general area as the
original Vanagon unit and aligned the inlet so that the plastic drip shield fit
again (anal-retentive, I know). Clears the back of the cluster as if it were
designed to do so! This solution should work for any cluster one would like to
put in!
On the choice of cluster.... Well to start with, I have always thought (going
back to March of '82 when I placed the order for Westfalia for factory
delivery) that the instrument cluster was a tacky design. The fake molded sensor
lights particularly irritated me! I later years, I added the tach, the oil
pressure warning circuits, the VSS speed sensor and redesigned the warning light
package to give right and left turn signal lights, added cruise control lights,
finally adding multicolor LEDs to the fake center section to monitor radiator
fan speed, intercooler fan speeds, fog and driving lights and A/C control
parameters. But I never liked the look of the thing.
When I decided to TDi the Vanagon, my orders to the salvage yard were that I
wanted it all - engine, hoses, all wires and sensors. To my surprise, they
included the speedometer cluster. The three gauge pattern carried the same info
as the Vanagon cluster, but much more cleanly. The row of sensor lights along
the bottom of the cluster was very tasteful and, the LCD display made it
possible to add the MFA (multifunction display) to the package. I noticed
immediately that the size of the Passat cluster was just a bit larger than the vanagon
center section, so I decided it was time to generate a cluster that was good on
the eyes and technically compatible with the Vanagon. The MFA was a key part
of the equation, since I could integrate a miles per gallon function together
with monitors for oil temperature and all OBD II sensed engine variables (the
son is hacking the MFA controller to display all VAG.com accessible info).
So, while the A4 cluster is nice and the later sport clusters from the Passat
and G/J series are very impressive, they were somehow not in the same design
paradigm as the classic Vanagon shape. The approach I used is compatible with
any cluster. I chose not to go the digital monitor approach or to rebuild with
aftermarket gauges (VDO or other), although the 9 gauge custom cluster seen
here on the list recently pushed me from design to implementation.
Key details ... Needed - Dremel tool, JB Weld, '97 Passat instrument bezel,
'95 to '97 Passat instrument cluster, one or more Vanagon instrument cluster
bezels, flexible bumper spray paint, 20+ hours, high quality source of KMZT-FM
in garage. To begin, I cut away all the instrument pod from the plastic vanagon
bezel to a distance of about 1 inch from the front face. I cut off the bezel
support pieces so I could reassemble them to the cluster in the end. I then
took the plastic '97 instrument bezel and used it to shape the remaining vanagon
bezel surface. When I has the shape right (easier than it sounds with the
Dremel tool) I bonded the passat bezel to the vanagon plastic. This left a series
of open areas since the smooth transitions at the top and sides were not a
part of the Vanagon shape. These areas were filled with JB Weld then smoothed
and shaped by hand with various wet/dry sanding papers. On the back side of the
Vanagon cluster, I removed the plastic shell support for everything except for
the light switch and the lowest switch position on the right. I then filled
and smoothed the front surface in preparation for cutting the two 2 1/16 gauges
that I wanted as part of the cluster. I then bonded the cluster support pi
eces from the original vanagon bezel to the revised unit. I set the positions in
a jig, heat treated the plastic for a slightly different takeoff angel to meet
the original mount point without stress. These support pieces were about
0.250 inches further to the right and left than the original. I then fitted the
Passat cluster (took off some interfering tabs) and reinforced the remaining
structure with JB Weld. The gauge holes and switch areas were then clearanced and
a final sanding polish performed before painting with the flexible semi-gloss
black. The paint removed fine sanding damage with a high film strength drying
surface. Did a test fit and all was well including the latched top pod cover.
On the instrument cluster mods ... I added the boost (0-30 psi) and EGT
gauges in an excellent 270 degree sweep unit made by Speedhut. The MFA cluster
(not part of the original Passat TDi cluster) was pieced together from a '95
Passat GLs (4 cylinder motor) cluster with turn signal (has cruise control
switch) and wiper (has MFA controller) stalks from same. (This idea came from Chris
Bell on the TDIClub list). The tach sensing was correct for the TDi engine.
The temperature gauge is appropriate for the sensor on the engine. The gas gauge
worked for full scale to empty due to VW internal standardization policy! The
speedo sensor is electronic. I cut up a GTi speedo cluster to get the Hall
effect sensor wheel and mount shell. Added a VW three wire VSS sensor and turned
it all into a 2.0 x 2.0 x 1.5 inch adaptor that pops onto the end of the
Vanagon speedometer cable. I convert the pulses from this Hall sensor packet to
the frequency (pulses per mile) needed by the Passat cluster with either a
Dakota Digital pulse frequency converter of a circuit for variable calibration
designed by my son. In the custom circuit, we would calibrate the speedometer with
a GPS system and thereby lock it on for any tire combination.
Whew, sorry for the length but not it will be in the archives, should someone
else be inflicted with a rainy weekend. To see pictures, check out:
http://www.members.shaw.ca/albell/mods.html
Frank Grunthaner
| 
