4" Dual GPS Speedometer + Tachometer | 80 MPH / 8K RPM

We recommend hooking up your diesel tachometer to either the alternator R or W terminal, crank sensor signal, or magnetic pulse sensor.

1. To calibrate it, while hold the button down start the engine. The pointer to move to 1k rpm when in calibration
2. Next, move the pointer to where your idle is by holding the button down. If you release and hold down again, it will move the other direction.
3. Release the button, and after a few seconds the pointer will go to 0 and then current rpm.
4. Your calibration is done! It is permanently stored in memory.
5. This can be done multiple times if needed.

To get into PPR (Pulses Per Revolution) calibration, you will press and hold the button down while power the gauge on (or menu button if you have 2 on the front)

You will determine your PPR based on the chart below. While in calibration, pressing and releasing the button will cycle through the options. 

After 5 seconds, the gauge will exit calibration and save the PPR the pointer is currently on, return to 0 then show the RPM reading.

If you have a dual speedometer + tachometer, then you will set the calibration on the screen display instead, holding button down while powering on, press and release button to cycle through menu options, hold the button for 3-4 seconds to select "Set pulses per rev" menu option, then press and release to increase PPR. The PPR will save after 5 seconds of inactivity.

Calibrating single gauge tachometer:

They are incredibly simple and straightforward to install! Our GPS Speedometers connect to the Global Positioning System through an antenna, and don't require a transmission sensor. (The antennas are included with the GPS Speedometers, too!) This makes them very easy to install in vehicles that lack electronic sensor output.

You need to connect the tachometer to the vehicle's ignition system, or ECU tach output if applicable. Exactly where you connect to will depend on your vehicle's fuel delivery system. The PPR (Pulses Per Revolution) calibration will also vary based on where your signal is and how many cylinders your engine is.

If you have a single coil distributor, you will connect the signal to the negative coil terminal.

If you have a coil pack or coil on plug, you will connect to any trigger wire. (The wire that will be a different color from coil to coil)

If you have an OEM ECU, you will likely need a 4.7 KiloOhm pull up resistor tied to 12v to help strengthen the signal.

The GPS speedometer updates 4 to 5 times per second. The update rate is fast enough to not show any noticeable delay in keeping up with speed under hard acceleration or braking. Our GPS speedometer are used without issues in many performance cars!

Please view the diagram below for more information on how to connect a Speedhut Tachometer to an LS ECU.

Setup the Tachometer to run 2 pulses per rev when connecting it to the engines' ECU.

If you exceed your speedometer's maximum speed, the pointer will remain at the maximum speed position, and will not move below the maximum speed position until your speed drops back into a readable range.

Luckily for all of the speed-fiends out there, this will NOT damage the speedometer.

If the speed exceeds the analog range and you are using a GPS speedometer with an LCD display then you can use the digital speed display feature to view your current speed.

Our GPS speedometers rarely drop signal. They use a powerful 'active' antenna which perform exceptionally well in all driving environments, including tall buildings, canyons, and extreme weather such as rain and snow. In most cases, the only time you will experience a signal loss is while driving in tunnels or in parking garages.

If your tachometer is constantly jumping around, it is likely electrical interference. You can try shielding the signal wire with aluminum foil or foil tape and tie each end to ground, it is pretty common as the components the signal wire ties to tend to be electrically noisy.

No, but we offer three different antenna lengths for you to choose from: 5', 9.8' and 15'.

The best location for the GPS antenna to be mounted is on the roof of the vehicle. The GPS antenna is waterproof and magnetic. If the roof is inaccessible, the antenna can be mounted on the top of the dashboard in a place with maximum exposure to the sky.

Metal will block the GPS signal, but the GPS antenna can receive a signal through thin materials like wood, glass, fiberglass, and plastic.

Yes, we can do that for you!

Please tell us your mileage in the 'Order Comments', and we will program your odometer when we build your gauge.

If you already own one of these speedometers you can send it back to us and we can program the miles into the odometer (shipping charges will apply).