Installation and tuning of NOS dry kit 5176
By Jordon Musser

Why Nitrous
A few months ago I decided I wanted to go faster. I looked into installing a cam and heads, but after checking autocross rules, I realized that this would put my in CP, which is a really high "race car" class that I could not be competitive in.  The only "big" power mod I could do and remain in ESP is nitrous.

Wet or Dry
Now, a wet or dry nitrous system.  A dry nitrous system uses the stock fuel injectors to supply the additional fuel needed to keep the engine from running lean on nitrous.   A wet system uses a fogger nozzle to inject the fuel in the same place as the nitrous.  Both dry and wet systems have there ups and downs, but it seems that a dry system and safer for a 125hp or less, and a wet is safer for 150hp+.  Downsides of a dry kit being you can't really tune the fuel, but you don't have to worry about spraying nitrous with out fuel because of the way a dry kit is designed, if there is nitrous the additional fuel IS flowing.  No worrying about malfunctioning fuel solenoids etc.   The trick to getting the dry system to be 100% safe is setting it up properly.   UPDATE: I am currently installing a CompuCar wet plate system on my new 383, with plans to spray the heck out of it.  So if you want to go wet, check back soon for instructions on the wet kit install and a NMM! Once again my instructions will outline how to install it safely!

Additional Supplies
On top of the actual NOS nitrous kit, you will need 24pound SVO injectors, a fuel pressure gauge, a 4an T-fitting, a 4an female-female fitting, and a Bosch relay, RPM switch( I used a summit one with dip switches), a 59/52 jet, an extra 42 jet, and a core remover for the shrader valve

Installation The actually install of the nitrous kit is simply and straight forward.  I did however make a few changes, such as running the main line in the car, under the carpet. I mounted the bottle in the spare tire well.  I also used a relay instead of running all that wire in and out of the car, and I also hooked up two LEDs to monitor system arm and activation.  To make sure the nitrous didn't flow below 3000 rpm, I also used a summit RPM switch which was about $45.  See my wiring diagram for details.  And no matter what anybody says, you NEED the T-rex/NOS in-line fuel pump.  I had planned to put some pictures of my complete nitrous install up here, but well I ended up installing it totally stealth.. as in you can't see any of it and therefor can't take pictures of it.

(Click to enlarge)

Instead  of hooking the Fuel Safety Switch directly to the fuel rail, connect the female-female fitting to the fuel rail (after removing the core from the shrader valve), and then screw the t-fitting to the other end of the female-female coupler.. Now you can hook the fuel pressure safety switch to one side of the T, and the fuel pressure gauge to the other.  Also, instead of installing the 67 nitrous nitrous jet (150hp) install the 42 jet for nitrous( for testing purposes), and the 42 also for fuel.  Also install the 24 pound SVO injectors.  These are needed as the stock injectors can lock up... that is bad.

Testing
Wedge the fuel pressure gauge in the windshield wiper blade so that you can monitor fuel pressure while testing.  Disconnect the nitrous line that runs to the Fan Nozzle so that you can test to see if the nitrous is working properly, without putting actually spraying nitrous in the motor.  Prop the line up so you can see the nitrous spray out while seated in the drivers seat.  Arm the system, and make sure the arm light came on.  Now rev the motor to about 3000rpm(if that's what you have the RPM switch set for), then mash the gas just for a sec, you should see nitrous flow from the line, and the fuel pressure should spike to 80-90psi for a second.  If the nitrous doesn't flow, start checking all your connections and make sure you opened the bottle.   If you wired your car like mine, check if the activation light came on, if it did then the problem is under the hood, probably the solenoid wiring.  If the light did not come on, the wiring problem is somewhere before the relay.

Assuming all is well, rehook up the nitrous line, close the hood and find a open road to test on.  Before testing the system for the first time in the car, make sure the bottle pressure is between 900-1000, this is optimal.  You should ALWAYS check the bottle pressure before spraying!!! Arm the system, get the car into 2nd at about 2000, and then mash the gas.. the car will slowly rev toward 3000, when the nitrous comes on at 3000 (that's where the RPM switch should be set) you will feel a light kick.. but not much.  You need to be watching the fuel pressure gauge.  It should stay at at least 80psi (probably closer to 90psi), all the way through the gear.   If it dips as you run through 2nd, something is wrong with the in-line pump, or maybe the in tank pump.  Check it out and repair it before you start jetting up.   If all is well, install the 59 jet (125hp, or 52 jet for 100hp) and head back out.   This time when the nitrous hits, you WILL feel it.. and it will bring a smile to your face, but remember to watch the fuel pressure gauge, if it EVER drops below about 80psi, get out of the nitrous and determine why the fuel system is lacking.  I use a Scanmaster to watch my 02s, which never drop below 940.. very rich, very safe.

Performance
The day I tested the nitrous it was VERY hot, so my car was off a little.   My car went from a 13.1 @ 106.5 that day to 11.8 @ 118 with the 100hp jet.  Yeeha.