How to Install a Nitrous System
NOS Kit Number 5151
This is a very quick and basic article on how to install the NOS kit 5151, for the TPI equipped Camaro, Firebird, and Corvette. The information here is taken directly from the installation manual provided by NOS. Of course the manual is more detailed, but the point of this article is to give a brief explanation of installation procedures. A full installation manual can be purchased separately from NOS for $5.00. The manual is included with the setup.
Step 1: Mounting the Bottle
NOS recommends mounting the bottle in the well, in the hatch area, by using the supplied brackets. Because of the open compartment in the 3rd generation F-Bodies a safety blow-down tube is used. The bottle should be turned approximately 45 degrees so the label is facing towards the front of the car. This will place the pickup tube near the back of the bottle where the an ample amount of nitrous will be during acceleration. The bottle brackets need to be screwed down to the floor of the well to prevent the bottle from moving around during acceleration. Two holes will need to be drilled in the floor. One of these holes is for the safety blow-down tube and the other is for the nitrous feed line.
Step 2: Injector Plate Mounting
First remove throttle linkage and throttle body. Then install plate and gaskets onto the upper plenum with the spray bar orifices facing into the upper plenum. Then reinstall the throttle body and linkage with the extended bolts and throttle linkage. Simple.
Step 3: Fuel feed lines
**For safety disconnect the negative terminal of the battery** Locate the schrader valve on the fuel rail. Remove protective black cap and decore the schrader valve using a tire valve core tool.
Step 4: Fuel and Nitrous solenoids
Place the nitrous solenoid in a padded vice and install the supplied nitrous filter into the inlet side of the solenoid using Teflon tape. Next, install the supplied 2-ft. braided line with the blue fittings, to the outlet side of the solenoid using Teflon tape.. Now place the Fuel solenoid in the vice and install the 2-ft. Piece of braided line that has red fittings to the inlet side of the solenoid (of course using Teflon tape). Then install the other 2-ft. Piece of braided line, with the r ed fittings, to the outlet side of the solenoid. (Don’t forget the Teflon tape or you will have a very Hazardous Leak!!) Next, mount the fuel and nitrous solenoids to the solenoid mounting bracket. Now mount the bracket in a place where the fuel feed line will be able to reach the solenoid and at the same time be able to reach the injector plate. As shown in the picture, the bracket was mounted to the strut tower. Connect the fuel feed line to the schrader valve, and connect the remaining lines to the injector plate. **Note – All N.P.T. fittings must be sealed with Teflon Tape!**
Step 5: Nitrous feed line routing.
This is a simple step, but needs a lot of attention. Basically connect the supplied braided line to the valve on the bottle and to the Nitrous solenoid. Routing the line under the car needs to be done properly. Make sure the line isn’t near any moving parts. If this line gets broken while the bottle valve is opened, a full bottle will empty in approximately 1 minute. ** Note – before connecting line to the Nitrous solenoid, It is a good idea to purge the bottle once to release any condensation that may have gathered inside. Basically to do this just open the bottle for a few seconds.**
Step 6: Throttle Micro-Switch Installation
The micro-switch is mounted to the throttle bracket. This switch is what actually activates the solenoids. Therefore proper installation is essential. Adjust the switch so that at wide open throttle the switch is depressed. For proper accuracy, have a friend sit in the car and floor the accelerator pedal. At full throttle you should here a quiet click. This means the switch has been activated. Make adjustments so that the switch is activated only at full throttle. This will ensure the computer is in an open-loop and the fuel mixture is adequate.
Step 7: Wiring of the system.
This step is probably the hardest, but can still be done by you. See picture for exploded view of system. The system is simple in that you have two switches to activate for the system to be operative. The first switch is mounted in the car and activated first. This switch should be on whenever you are ready to hit the throttle. The first switch supplies the power to the throttle switch. Then, when the throttle is fully opened, the throttle switch activates the solenoids to open and release fuel and nitrous into the system. The system has its own power and ground, and the actual power to the solenoids is run through a supplied relay.
Step 8: Preparing for operation
Reconnect the negative terminal on the battery and turn ignition on. Check for leaks at this time at all fuel connections. Then open valve on the bottle. Check for leaks at all nitrous connections. Temporarily disconnect the ground wire from the Nitrous solenoid. Activate the switch mounted inside the car. Start engine and have a friend rev to 2500 RPM. Manually depress throttle switch for a second or two, to open Fuel solenoid. At this time you should notice a bog in the engine. This means the electrical system is functioning properly. Reconnect ground wire to Nitrous solenoid. Find yourself an open street and LET IT RIP!!!
NOS system 5151 have adjustable Jets to properly set your horsepower levels. NOS recommends 100 horsepower for a 305 and up to 150 horsepower for a 350. NOS states that the stock fuel pump is adequate for these levels of horsepower and the stock timing does not need to be adjusted. This is a very thorough kit that comes complete with everything you will need for proper installation.
There are a few parts I recommend installing along with this kit. For proper operation of the nitrous system the nitrous pressure must be approximately 900 psi. With the temperature constantly changing it is a good idea to install a Nitrous Pressure gauge. This will put you in control of how much pressure is actually getting to the solenoid. Personally, I would recommend an Auto Meter Nitrous Pressure gauge. I would also recommend installing an Auto Meter electric Fuel Pressure gauge. This will allow you to keep an eye on fuel pressure for proper tuning. I do not feel that stock fuel pressure settings are adequate. It is better to be safe than sorry so I bumped up my fuel pressure by 2 psi. These gauges can be easily installed by using the NOS gauge adaptors. If you are using an aftermarket CHIP for your car then an adjustable timing retard may also be a good idea. Most aftermarket chips have a really aggressive timing curve and NOS does not recommend that their kit be used in conjunction with one of these chips. Since it seems that one of the first mods that everyone does is a CHIP, then an adjustable timing retard such as the one MSD offers is a perfect compliment to the nitrous system. The timing retard can be wired up in such a way that when the nitrous system is activated the timing retard is activated. Then as RPM’s increase, timing decreases.
Nitrous Oxide Systems
5930 Lakeshore Dr.
Cypress, CA 90630
Autotronic Controls (MSD)
1490 Henry Brennan Dr.
El Paso, TX
Auto Meter Products
413 W. Elm St.
Sycamore, IL 60178