Attention: TDR Forum Junkies 
The reason for 4 solenoids is the need volume of nitrous is such that four are needed. I spool on the trans brake , with one solenoid , this is accomplished by the NX SX II d two stage progressive controller . This initial stage is brought on at about 20% of the full on flow of that one solenoid, and is ramped up to 100% as the motor will take the nitrous , and this aids in spooling the turbo. Just as I let off the Tran brake, the second stage comes on , this stage is a made up of up to the other three solenoids . this stage is ramped in at the truck goes down the track and is able to take the power , and is fully programmable. This system is the ultimate and way to extreme for most sets up , but the controller is the same one used in the street set up. This controller pulses the solenoids at a programmable frequency . in the past variable controller would work by opening and closing the solenoids faster and faster as more nitrous was needed. The NX system lets you pick the frequency that you choose . but they recommend no faster the 16 times a second , thru a great deal of R&D they have found that this gives the best life span for the solenoids , and in testing has shown that there is no degradation in there life span over non progressive system. After you chouse the number of times a second that you cycle the solenoids , you pick the time , and the percentage you want the nitrous to come on, this is easily as dragging a graph on the computer screen. This gives you the ability to bring on , nitrous and hold that percentage , and then ramp it up again , and hold , until the solenoids are fully on.
Here are the specs of this NX controller
· 2 independent channels
· Programmable ramp times (0. 1 - 10. 0 sec)
· Programmable delay times (0. 1 - 10. 0 sec)
· RPM or Time based linear ramp or multi-point curve
· Integrated wide-open-throttle detection
· 1st gear lock-out
· User configurable for rising or falling TPS signal
· Supports low voltage tach signals as low as 3 volts
· Works with irregular tach signals such as V10 and 3cyl
· Easy to use graphic set-up menus using PC USB
· Inputs for manual enable/disable or transmission brake, throttle position, tach signal
· Integrated LEDs for WOT, stage 1 RPM window, stage 2 RPM window
· High current solenoid driver with 40 amp load capacity (continuous duty)
The 2-STAGE PROGRESSIVE CONTROLLER combines the functions of a 2-STAGE TPS AND RPM WINDOW SWITCH and HIGH CURRENT SOLENOID DRIVER all into one very compact module. It can progressively drive two channels, each with a 40 amp load capacity (continuous duty). The device also supports low-voltage OEM, V10 or 3 cylinder TACH signals without the need for additional adapters. It works with most OEM throttle position sensors including most drive-by-wire vehicles. This device also includes a "real curve" ramp which allows you to create a progressive curve instead of just a ramp, and the ramp can be either time based or RPM based. All this and only the size of a spark plug box.
The 2-STAGE PROGRESSIVE CONTROLLER is built for the racing environment to withstand heat, vibration, dirt and water. It is designed to operate over the temperature range from -40 to +185 degrees Fahrenheit (-40 to +85 degrees Celsius).
Here are the specs of this NX controller
· 2 independent channels
· Programmable ramp times (0. 1 - 10. 0 sec)
· Programmable delay times (0. 1 - 10. 0 sec)
· RPM or Time based linear ramp or multi-point curve
· Integrated wide-open-throttle detection
· 1st gear lock-out
· User configurable for rising or falling TPS signal
· Supports low voltage tach signals as low as 3 volts
· Works with irregular tach signals such as V10 and 3cyl
· Easy to use graphic set-up menus using PC USB
· Inputs for manual enable/disable or transmission brake, throttle position, tach signal
· Integrated LEDs for WOT, stage 1 RPM window, stage 2 RPM window
· High current solenoid driver with 40 amp load capacity (continuous duty)
The 2-STAGE PROGRESSIVE CONTROLLER combines the functions of a 2-STAGE TPS AND RPM WINDOW SWITCH and HIGH CURRENT SOLENOID DRIVER all into one very compact module. It can progressively drive two channels, each with a 40 amp load capacity (continuous duty). The device also supports low-voltage OEM, V10 or 3 cylinder TACH signals without the need for additional adapters. It works with most OEM throttle position sensors including most drive-by-wire vehicles. This device also includes a "real curve" ramp which allows you to create a progressive curve instead of just a ramp, and the ramp can be either time based or RPM based. All this and only the size of a spark plug box.
The 2-STAGE PROGRESSIVE CONTROLLER is built for the racing environment to withstand heat, vibration, dirt and water. It is designed to operate over the temperature range from -40 to +185 degrees Fahrenheit (-40 to +85 degrees Celsius).
