Installing Nitrous Oxide on an 2005 Magnum

Since we really don't like drilling holes in someone else's new car, we decided to mount our control unit with an existing fastener on the inner fender. We also grounded the unit to the same fastener.

To supply fuel to the nitrous control unit, Zex supplies a new fuel feed line with a provision for an additional fitting.

The new fuel line simply clips into place where the original fuel supply line went. Now the fuel line can be routed from the new line to the control unit.

Bottle position is important in any nitrous system. We installed ours in the Magnum's rear cargo area with the mounts included with the kit. The valve should be higher than the bottom of the bottle, and having the valve face the front of the car is optimum.

We routed our nitrous supply line from the engine bay, under the car, then through one of the plastic plugs in the rear floor just ahead of the rear seat and back to the cargo compartment where our bottle is.

With our lines routed and our components in place, we installed all the remaining high-pressure lines.

Wiring the system was easy. we simply grounded the black wire, ran the red wire through the firewall to a 12-volt supply and arming switch, then the remaining white wire was tied to the Throttle Position Sensor output voltage wire.

After wiring the system, the throttle must be opened without the engine running so the Zex control unit can "learn" the voltage of the TPS switch. Since the new Hemis are throttle by wire, the gas pedal only opens the actual throttle blades with the engine running, so you'll have to manually open the blades with the air inlet off to complete this procedure.

Nitrous oxide and fuel are metered by these jets in the nozzle. Zex includes jets for 75, 100, and 125hp tuning. We started with the 75hp jets so in case we have a problem with the system, we'll be less likely to do any major engine damage.

Since our Magnum has a Hyperpack performance tuner, we had to re-set the car's computer to stock settings. Computer tuners typically vary ignition timing, which can lead to detonation when nitrous oxide is used. Setting the computer back to stock settings ensures the ignition timing is suitable for nitrous oxide use.

Though a rain shower would end our test session before we could step the nitrous up above its 75hp level, we managed several 13.90 passes in the Florida heat. Not bad for half a days work and a flip of the switch! Look for more thorough testing in future issues and on our web site, moparmuslcemagazine.com.

After making a baseline pass with no nitrous, our first nitrous pass netted a 13.97 in the quarter-mile, more than four-tenths of a second quicker than without nitrous!