The N2MB box is a multi function electronic interface that allows for an adjustable 2-step rev limiter. It also has a no-lift shift feature that pulls timing to allow smooth shifting without taking your foot off of the throttle. All the information on specs and features can be found HERE.
The N2MB box has 6 wires that need to be connected to work. YELLOW
, BLACK, and GREEN
The BLACK wire is the ground wire for the N2MB box. I mounted my box under the change holder in the center console. I just used one of the bolts that holds the metal support bracket to the floorpan.
/BLACK wire is a two-piece molded wire that is spliced into the power wire for the coils. On the Ecotec engines, this is the PINK wire at the top left of the plug-in on the ICM.
The PINK coil power wire needs to be cut and the BLACK half of the two-piece wire needs to be spliced into the wire TOWARDS the plug-in. The RED
half is spliced into the wire AWAY from the plug-in.
wire is tapped into the TPS output voltage wire from the TPS plug-in. This can be accomplished a couple of different ways. The TPS wire needed to tap into is a DARK BLUE wire. You can either tap into the wire close to the plug-in, or do as I did and tap in at the PCM.
The gray plug-in on the PCM is where you will need to tap into the wires. The TPS wire is PIN #31
on the PCM plug-in. The PCM is labeled as well as the plug-in with the numbers. If not sure if you have the correct wire, you can check continuity from the pin at the PCM to the plug-in at the TPS.
cut the TPS wire!!! The N2MB box only needs reference voltage from the TPS, it doesn't cut the signal. The recommended procedure is to remove some wire insulation from the TPS wire, wrap the BLUE
wire around the TPS wire, solder, and wrap with electrical tape.
wire is the RPM/Ignition wire for the N2MB box. On the Ecotecs, there is no cam sensor to tap into as recommended by N2MB. The best way to get this signal is to tap into the ground wire for the #1 fuel injector. As with the TPS wire, this can be done a couple of ways. I tapped into the fuel injector wire at the PCM, just like what was done with the TPS wire. At the PCM it is is a BLACK wire. As before, DO NOT
cut the fuel injector wire. Wrap, solder, and shrink or tape the YELLOW
wire around the fuel injector wire. On the gray plug in, this is PIN #51
at the PCM plug in.
The last wire needed to be spliced into is the GREEN
wire. It is the clutch pedal position wire. On cars equipped WITH
cruise control, you will have the cruise control release switch that deactivates the cruise control when the clutch pedal is depressed. This is what you will tap into to get clutch position for the N2MB box. It is the white switch pictured here.
The cruise switch is normally open until the clutch pedal is depressed and the circuit is completed, meaning one wire has constant voltage, and the other wire only receives voltage when the clutch is depressed. The GREEN
wire should be tapped into the wire that only receives voltage when the clutch pedal is depressed. Both wires coming from the plug-in are BROWN, so a DVOM should be used to determine which wire is the correct one to tap into. Once again, DO NOT
cut the wire, just wrap, solder, and tape.
On cars WITHOUT
cruise control such as mine, luckily GM included the bracket for cruise control switch on all of these cars no matter what. Its just a simple task of going to a junk yard or parts store and buying the switch and pigtail. It snaps into the bracket and has threads for switch adjustment.
On cars WITHOUT
cruise, you will have to get a 12 volt reference for one side of the switch. I used a fuse-tap from the ABS slot in my fuse box since it wasn't used. Just splice this wire into one side of the clutch switch pigtail. Splice the GREEN
wire into the other side of the switch pigtail.
Make sure that the switch is adjusted so it wont be engaged until the clutch is sufficiently depressed.
Once everything is installed and all wires properly secured, you can now program the WOT box for 2-step and no-lift shift settings. All of the instructions and programming software are available on N2MB's website.
As an added benefit, turbo cars should be able to build some boost coming off the line with the 2-step engaged. And my car sounds pretty good at a 4000 RPM bouncing rev limiter.
Currently #4 in Ecotec Forced Induction horsepower ratings. 505.8 WHP 414WTQ!!!
Currently 6th quickest Ecotec on the .org -12.453 @ 116.45 MPH!!!