[TONS of updates and pics on 2nd page]

[this is for off-road use only]

A little background info.

After hearing about plans for my buddy going supercharged in his AP2, I needed to do something quick before his upgrade took place. Im terribly low on income and need something I can keep secret... turns on in my head... Nitrous! So I did my research over the net. [keep in mind, this guy trolls s2ki 24/7!!! So asking for help is out of the question.] I finally end up with enough parts purchased from several different sellers (one of them discretely from s2ki) to put together a decent kit myself.

I photographed every step in as much detail as I could with plans for an s2ki write up/DIY for the lack of useful information on this website. Hopefully someone will benefit greatly from all of this.

[Anything attempted after reading above and beyond this point is completely 100% at your own risk. I am not liable for anything you do or break. You do not know me and I was never here... Nor did I even write this.]

So it begins.

Lets start with a 55 shot.
[end result upgraded to a 65 shot]

Here's what we're working with.

MY04 AP2 S2000
42,000 miles

mods: K&N FIPK air intake

What a gorgeous day for N20


ZEX EFI Wet Nitrous Kit (model #82021)


ZEX Bottle Heater


ZEX Window Switch (mine is actually made by DynoTune and looks different. Same install though.)


Autometer Full sweep Electric Nitrous Pressure Gauge

 

First of all... I made sure the kit was well hidden from plain view so my surprise wouldn't be spoiled.


Strip the trunk. Figure out where to put the bottle... Try different fitments and what-not. This is not difficult. Also, Figure out where you will run the N20 line to the engine. DO NOT run it through the inside of the car. Would you run your fuel line through the interior? Didn't think so. So, down and under is safest.


Ok, I am pointing to a nice flat spot where I can drill a hole and run the N20 line out to the engine.


This is the underside of that same spot. (Took off right rear wheel to get here) This will be right next to the ABS Sensor wire.


So get a drill and get yourself a hole goin. I used a step drill to make sure it was nice and round. This is very thin metal here, so be careful not to get cut. I used a rubber grommet I had found layin around that just fit perfectly. This will ensure that the line is not torn or punctured.


Feed the line through. (Knot one end so it doesn't pull all the way through.)



Bottom side.


Weave it through the under guts of the car making sure nothing gets pinched or sinched. Go above the drive train as high as you can. I used strong zip-ties to secure the line.


Follow the fuel line up the the front of the car. Dont worry about getting inside of that cage that the fuel line is in. Just secure it to the bottom and follow it on up to the engine. Just leave it secured for now and we will get to it later.

 

Now we can mount the Nitrous Control Unit (I will call this the NCU from now on).

To keep it out of plain sight, I mounted this to the back of my K&N FIPK air box. I used some scrap metal for the mounting bracket and soft velcro to soften the grip on the NCU (and this will keep it from gettin so scratched up).



Test fitting to see how well it is hidden.



I also took this time to extend the wires coming from the NCU for making my life a little easier after this is in and needs to be wired. Highly recommended. Otherwise you are this guy ->
I used heat shrink wrap on every wire. (Highly recommended)

Now wire up the NCU. (actually the Nitrous Management Unit, but whatever this is my write up).

Black to a ground
White to TPS wire (Throttle Position Sensor)
Red to arming switch (interior)



Locate your TPS wire. It is the RED/BLACK wire in the center coming from the TPS located on the left side of the Throttle body. Just pull back the rubber cover to expose.




I used a simple wire tap to connect the TPS wire.

 

TEFLON TAPE IS YOUR BEST FRIEND!

[update] Teflon tape is unnecessary for compression fittings.
[update 01/19/10] Try Teflon paste.
(I have had no problems with using Teflon tape on my fittings. If you are concerned about clogging your hoses, just read the rest of this thread and decide for yourself what is best)

Teflon the heck out of all your connections while you still have the kit out of the car. It is next to impossible once its all installed and you need to get down in there. (this is the same stuff you used when you installed your new shower faucet). Get it at any auto parts store.


Make sure all connections are tight... And please try not to over tighten anything because they are small pieces and they WILL break. Trust me, I know.

This is also a great time to make sure you have all your crap organized some-what. haha. My office.


Mounting the Purge Solenoid

Here is a short video I made during install. [this is prior to the dual setup]
http://www.youtube.com/redlude5000

Again, I took advantage of my K&N FIPK air box. I just mounted this directly under the box and it rests of the cross bar. Connect your fittings and run the power wire inside trough the fire wall. You'll need it later to add a switch. The same goes for wiring the NCU.



Go ahead and find a clever spot to run your purge line. I am using a dual purge, so naturally I ran two lines to exit right under each door. I used the under cross bar as a hose-holder -if you will- to secure the lines. The zip ties are temporary until I find something better to hold it.

 

Now that you have the NCU (or NMU as ZEX likes to call it)... There is one more hose to run... Time to tap the fuel line! yay..

Ok, honestly.. this scared the crap out of me. I had no pictures to go by and wasnt 100% sure I was about to cut the correct line. UNTIL I got under the car and started peekin around.

Keep in mind, this is a 2004. It may be different for newer or older but I doubt it. Follow the plastic mushroom looking thing (see below photo) from the fuel rail down through the intake manifold and under the engine. You will find the fuel line marked "FUEL" printed right on it. phew.



Now BEFORE YOU GO CUTTING AWAY! You must release the fuel line pressure so you dont go makin a huge mess.

1. Take off the gas cap and set it aside. (yes, the gas cap)
2. Let the car sit for at least 2 hours. (fuel pressure is released during this time, go watch some tv)
3. DO NOT put the key in the car. Just set it down. (this is so you dont accidentally prime the engine, if you do, just start this process over again.)

Ok, get your fuel line T-tap and some nice big cutters. I found that the supplied fuel T-tap is PERFECT for the stock fuel line. I could not be happier with the fitment. Make sure you place your small ring clamps over each cut end of the hose before you place the tap.

Cut that sucker. Leave about 2-3 inches of hose connected to the hard fuel line so your t-tap will fit. Otherwise you are screwed and need to have a chat with yourself.

Wear protection! A small amount of gas will leak out when you cut. So have some towels on hand.





see "FUEL'? nice, huh? Thanks Honda!

Finished fuel tap. Now pat yourself on the back if you didn't accidentally cut the return line.


Now, go ahead and connect all your steel braided lines to the NCU and get ready for the wiring.

 

Tap your air intake using the supplied tool. If you dont have one, just got to your local auto parts store. This is a 1/8 NPT tap



Get yourself a started hole going that is just smaller than the tap size.
Slowly turn your tap (with pressure) into your intake piping. Dont rush this. I also used a strong plastic to metal epoxy to secure the nozzle. Similar to locktite.



The ZEX instructions tell you to tap the intake from 6" to 18" from the throttle body. but realistically, we dont have that kind of room in the S2k. I went with about 4-5 inches.




Whatever you do, make sure the nozzle is pointed INTO the TB!!



Clean out the intake of any scrap pieces/dust and make sure the nozzle is tight and doesn't wiggle.

You can connect your intake back to the car now. Connect the 2 foot N20 and fuel delivery lines to the nozzle after you put in your pills (jets). It will not be a pretty sight when you forget the pills and try to spray for the first time.

I ordered .017 (fuel) and .032 (N20) size jets for a 55 HP gain. I later swapped the jets to sizes .016 (fuel) and .036 (N20) for a 65HP gain. Go to ZEX.com to find your sizes.

 

Now for the fun part. If you are not an electrical guru, or your not comfy doin this part... get some help and try not to fry yourself. It doesnt need to look as nice as this, but I had a lot of time to get everything perfect.

You will need to wire a separate relay for each unit you want to control, the NCU, Purge solenoid, and bottle heater. These all use a lot of power so when everything is running at once, nothing will be under powered. I am using ONE power source for this entire Nitrous system. This keeps me from cutting into random 12v wires that im not sure goes where.

I started off by making a distribution block to power the accessories.



Go to Radio Shack and find one of these. Using the yellow wire connectors, I am able to create four positive and four negative terminals for easy connections.



After many trial and error runs, I finally made the right connections for these relays (I have never worked with relays prior to this, now I'm a pro.) I recommend searching "Relay wiring diagram" in Google search. You will find plenty to work with.

Im not about to explain the electrical circuitry of the world so just read the instructions from ZEX.com and use Google seach.

Test your connections and switches. Doesnt need to look pretty right now, we'll get to that.


Label your relays. Also, get rid of unwanted wire length... Shorten what you dont need and save some yourself the trouble of a messy install!




From left to right; Bottle Heater, Purge, System Activation.


I mounted the "Brain" to a piece of plexy glass I picked up from Lowe's for around $2. Same with the switches. I even through in a "Kill Switch", which is just the green fuse placed inline with the 12v source... Just pull it out to deactivate the entire system (this can be reached from the drivers seat). Also, cleaned it up a bit. nice?


This slides nicely under the dash just beneath the steering column. Completely out of sight.

Connect the Pressure gauge wiring to the remaining 12v slot on the distribution block. (if you have an electrical pressure gauge)



I am using the DynoTune Window Switch for programming the NCU. The system will activate between 3500 and 8000 RPM and only at WOT. (wide open throttle). The programmer is mounted in front of my gauge cluster.

I mounted the gauge right by your left foot under the steering column. Perfect view from the drivers seat.


I found another bottle so Ill go ahead and mount it up as a spare!


Here's the finished product.


From beginning...


To end... Not a whole lot of difference huh?


I will get everything well hidden in the next day or two.

Now im tired and need sleep! Goodnight!

 

nice, hurry up and get to the fuel part, i was concerned the kit wouldn't come with the right connections for tapping the fuel line..

 

Dont worry, its comin!

[EDIT] Updated.

 

Maybe it started on fire or something