200 MPH Speedometer – The Build
Posted in 200 MPH Speedometer, Modifications on February 17th, 2010 by StewartHere is an in depth look at the 200 MPH Speedometer…
…that I built for the RoadMonster Gran Sport Project.
I wanted more of a “performance oriented” gauge cluster for this project.
Something that would match the overall theme of the car…
The trouble is…
…no one makes an aftermarket gauge cluster, gauge cluster overlay, or anything for these cars.
Here is the stock 1994 Buick Roadmaster 120 MPH speedometer that was removed.
The stock cluster is pretty sparse, and not much to look at…
A gauge cluster from a Canadian Buick Roadmaster was purchased:
The Canadian cluster looks the same, except that it reads to 200 KPH.
Now we need a new gauge panel face.
An original cluster face was scanned and sent to Sean at LEDmod.com.
Sean took the scan, and made some changes, such as changing it to read to 200 MPH, instead of KPH.
Sean then made a new white gauge face incorporating some logos that I wanted on the cluster.
I made the Buick Motorsports logo myself.
The Gran Sport logo started as photo of one of my exterior Gran Sport emblems, which was then digitized.
The Buick Tri-Shield was the final logo added.
Sean & I moved the logos around until I was happy with the placement.
I wanted this new gauge cluster to match the Auto Meter Arctic White Gauges in my Triple A Pillar Pod:
For the new cluster to match, I needed Orange Needles.
The stock needles are white…
I bought a couple of kinds of orange paint that matched the orange Auto Meter needles…
It turns out that the Krylon Short Cuts Paint Pen was the only paint I needed for this project.
This Krylon Paint Pen worked great!
Here is the needle that I am trying to match.
Yeah, that’s a boost gauge. I have future plans for it…
What I had to do was sand off all of the white paint from the back side of each needle.
It sounds easy, but you have to be careful.
The white line you see is actually on the front and the back of each needle.
The first third of the white line is on the front, on the black round base of each needle.
This white line can be painted over.
The remaining white paint on the back side of each needle has to be sanded off.
As the needles are clear, all the white paint on the back side has to be sanded off, or you won’t see the orange paint through the clear needle.
All the white paint must be sanded off, but you don’t want to damage any of the clear needle, or scratch the black base.
To make matters more challenging, the backside of each needle is not flat, it’s got a half-round indentation running the length of each needle. The sandpaper must be folded to fit into the indentation of the needle…
The pic above shows the first coat of orange paint. Several coats were required to get the needles just right…
The two pics below illustrate the back sides of the needles that must be painted.
It’s tedious work, but well worth it in the end…
Here we have the new face and repainted needles installed on the Canadian cluster.
The Shift Indicator was also repainted Orange, as it had become faded.
Since I had done a floor shift conversion, I could have easily just eliminated the shift indicator in the gauge cluster.
However, since the indicator in the dash is set up to function with the floor shifter, I kept it. I like that both gear indicators work in tandem.
A brand new (NOS) gauge cluster lens was purchased from GM and installed on the modified cluster:
Now the cluster is almost ready to be installed.
Almost, but not quite.
I still had to set the Canadian Odometer to match my Current Car’s Odometer / Actual Mileage.
I won’t bore you with the details here, but it was really a pain in the butt to reset the odometer.
It felt like the automotive equivalent of Rubik’s Cube…
Send me a message if you want the instructions on how to do this.
Suffice it to say that I got the “new” odometer to exactly match the “old” one…
Also, I had to install a Dakota Digital SGI-5 Speedometer Calibrator so the new cluster would read in MPH instead of KPH.
This unit from Dakota Digital was easy to calibrate.
There is only one wire to cut when installing the SGI-5. It’s the GREEN/WHITE wire going into the stock speedometer. Hook one end to INPUT, one to OUT 3, and of course, the power and ground. That’s it!
The process was even easier by doing this modification to a Buick Roadmaster Sedan. You see, the Climate Control Unit in the dash has the ability to be set into Diagnostic Mode. In Diagnostic Mode, there is a tachometer and a SPEEDOMETER function. Nice huh? I just set the Climate Control into diagnostic mode, set it to tell the car’s speed, and then calibrated the new cluster with the Dakota Digital Interface. Easy!
Here is the end result:
Now all of my gauges match.
Even the Fuel Pressure Gauge under the hood matches my new gauge cluster…
I finished off this cluster with green bulbs.
The Autometer Gauges in the A-Pillar have green lighting too.
All the gauges match the stock green lighting in the car.
It is important that everything matches IMHO.
Now I have a 200 MPH Speedometer / Gauge Cluster that matches the theme of my RoadMonster.
It really finishes off the interior quite nicely IMO.
What do you think?


























