Adding Gauges to Your Challenger for Closer Engine Monitoring

Oil Pressure: Measures the engine oil pressure. Sensor location above the oil filter. Available as mechanical or electric gauge. Useful or all Challenger owners to verify general engine health and lubricity. 

Boost: Measures the pressure, in relation to atmospheric pressure, that a supercharger or turbocharger is providing. There is typically a port or T-fitting you can hook into near the super/turbocharger prior to the waste gate. Can be mechanical or electric. Only needed for Challengers with forced induction.

A/F Ratio: Measures the stoichiometric ratio between air and fuel. Critical information for forced induction Challengers that are making big power. Read through a wideband oxygen sensor that installs into the header downstream. Uses an electronic sensor.

Exhaust Gas Temp (EGT): Measures the exhaust gas temperature which values reflect the air-to-fuel mixture. A low exhaust gas temperate likely indicates too rich a mixture and a high EGT likely indicates a lean mixture. Measured using a sensor in the exhaust downstream. Uses an electronic sender. An EGT gauge is a secondary means of monitoring combustion levels.

Voltmeter: Connecting to the battery and charging system, a voltmeter displays the condition of the charging system. Too high a voltage (above 16) would indict an overcharging situation whereas too low a voltage (below 11) would indicate a heavy discharge.

There are three common places to install extra gauges that won’t detract from the normal functionality and visibility of a Challenger’s interior. First up is the A-pillar. Mounting a 2 or 3 gauge pod on the A-pillar provides easy visual access to the gauges without obscuring anything else. 2-1/16” gauges fit nicely on the A-pillar and it is easy to remove the trim to run the necessary wiring or plumbing out of sight.

Next up is the center of the dash. There is more real estate to deal with here thus you are not limited to 2-1/16” gauges. On the other hand, Autometer does make a 3-gauge (using 2-1/16” gauges) dash pod that sits right in the middle and matches the factory dash. In this position, the gauges are easy to read and still allow for good visibility out the front. Wiring the gauges in this spot would be the trickiest as it is impossible to completely hide the wires or lines without drilling into the dash. 

The final location is on the ceiling. Again using 2-1/16” gauges, an overhead pod sitting just aft of the map lights is another common area where owners are installing extra gauges. However, anything bigger than 2-1/16” will affect visibility, and some owners report that the gauges are hard to read given their angle and proximity to your eye. Nonetheless, these overhead pods look really cool and can be completely functional – a win-win by all accounts. 

Mechanical gauges, in the scope of a Challenger (in fact, in pretty much all modern day vehicles) have been replaced by their electronic counterparts. Is it because they are bad or inaccurate? No, not at all. In fact, mechanical gauges are extremely reliable and accurate. They are reading the pressure (as an example) straight from the source and are not relying on a sensor interface. When diagnosing engine issues, many mechanics will hook up a set of external mechanical gauges in order to confirm that what the factory OEM gauges are reading is indeed accurate. 

So why switch over to electronic gauges? It is a matter of safety. Whatever fluid a mechanical gauge is set to read, that fluid is reaching the gauge itself. In the case of a mechanical fuel pressure gauge, if installed in the interior of your Challenger, this means that actual fuel will be present on the aft side of the firewall. From a safety perspective, this is highly dangerous as fuel (obviously) is a highly flammable liquid. In fact, having a mechanical fuel gauge in the interior of any car is now illegal, for this exact reason. Any type of leak or blowout would pose an immediate fire hazard and potentially a health hazard as well. Other gauges like oil pressure and coolant temperature are still allowed inside, however they pose similar health risks if the gauge and or line leaks or breaks. Hot, high pressure oil or coolant will then make a mess of the cabin and could potentially burn any occupants quite badly.

Electronic gauges are the exact opposite in terms of safety risks. No fluids actually enter the cabin. Instead, an electronic sensor measures the oil pressure (as an example) and converts it into an electronic signal that is sent to the gauge. While still fairly accurate, electronic gauges are not as reliable as a mechanical gauge. They are more complex and adding an extra sender into the equation increases the amount of things to break. Electronic senders do fail regularly or degrade in performance which leads to inaccurate readings (thus why mechanics use mechanical gauges to confirm the electronic ones). On the other hand, apart from safety, electronic gauges do allow a vast amount of data to be manipulated and displayed without taking up a lot of real estate. With three senders and three wires, you can have one gauge monitoring multiple parameters all at once. 

To expand on this, there are tuning devices available on the market that provide a 4-6” touchscreen that can access all the sensor data that is monitored by the ECU, and given the fact that everything is now being run electronically, there is a lot of data. Users can organize this raw sensor data on the screen and have as many parameters as they like show at any given time. Most of this data can even be logged, charted and exported to an external computer. Oil pressure, temperature, fuel pressure, coolant temperature, transmission temperature, exhaust gas temperature, injector capacity, fuel flow etc – all of these parameters and many more can be monitored through a single digital device.