For those who have already read this there was a slight mistake in the wiring. You need to run the ground from the msd box the yellow wire to the ground on the relay. The solenoids need to be directly grounded. You can do this by grounding them directly to the bolt holding the bracket. Just make sure to scuff the paint on the battery tray to get a good ground source.
It has now been corrected below also. You can thank DARK-SRT4 for this bit of info. I contacted msd and they stated that he was correct. I bow down in my ignorance to Dark-SRT4
This is for a general nitrous install. Kits like Zex's are a bit easier.
1. Bottle mounting. The bottle must be mounted with the valve handle facing the front of the vehicle unless otherwise stated by the manufacturer. The siphon tube must also be at the bottom of the bottle. With most bottles this will have the label facing up and the. Place the two mounting brakets loosely on the bottle with the taller one at the front of the bottle. A good place for the bottle is in the wheel well where the spare goes. If you want a clean install romove the carpeting before drilling a hole for the line to go through. You can remove the drain holes to run the line through but that limits the placement of the bottle. Drill a hole directly under the nozzle connector. Make sure it is away from all important accessories under the car. Place the two brakets far enough apart to hold the bottle in place and use the brackets as guides to drill the holes. I would use bolts with locking nuts to secure the brackets. Once you have all the holes drilled place a rubber gromet where your nitrous line is going to be. Remove all the stuff and place the carpet back in the car and put a hole just big enough for the bolts and your nitrous line. Secure the bottle. Install your pressure gauge and use teflon paste, not tape, to help seal the threads. Install your bottle nut onto the valve making sure the washer is in place or you will have leaks. Run the nitrous line through the hole and under the car. I would loosely attach it to the bottle to make sure you dont pull it to far out.
2. Run the nitrous line. Run the nitrous line underneath the car generally following the fuel lines using ZIP ties to hold it in place. If you go through any parts of the car(holes) make sure to use a rubber grommet. If it looks like it will rub at some point under the car you can just wrap it tightly with something like Electrical tape, but you shouldnt have to do this. Just find a different route to follow. When you get to the engine compartment run the line over the right side(if you were facing the front of the car) of the transmison but make sure it is not near any moving parts and as far away from the exaust and turbo as you can get it. You want the line to go to the front of the underside of the battery tray.
3. Attach solenoids. Remove the battery, the airbox, and all the upper inlet hoses up to the throttle body. There is a bolt attached to the front of the battery tray on the bottom of the tray. This is a great place to attach the solenoids. First Attach the fuel and nitrous fittings to the solenoids.Apply teflon paste to the fittings, hose ends do not require paste they seal on the flare side of the fitting. Generally red fittings are for fuel, blue ar for nitrous. Then attach the solenoids to there bracket. Now just attach the bracket to the battery tray using the one bolt in the bottom front of the tray. You may have to drill out the hole on the bracket to make it fit. You want the solenoids to go underneath the battery tray as it is hidden and there is plenty of room there. Do not fully tighten the bolt holding the bracket as you may have to adjust it a bit to the right or left to keep from hitting the bottom of the tray or the transmission.
4. Install nozel. The best place I have found on the SRT4 to place the nozel is in the hard part of the plastic on the air inlet hose connecting the Intercooler to the throttle body. You need to be at least 5 inches from the throttle body, but no more than 12 inches. Drill a hole, probably a 1/4 inch hole, on the upper side of the air inlet hose (near the red vacume line). You need to place fit all the lines before you do to make sure that neither the nozel or lines will hit the transmission. It is somewhat of a tight fit but it can be done. If you put it in the right place no one will be able to see it without removing the air-box. Install the nozel in the hose making sure that the discharge side is facing the throttle body. Secure the nozel with the nozel braket making sure to use some sort of threadlock. Do not use the permanent kind. Make sure the nozel seals very tightly without overtightening the nozel holder or you will get a vacuum leak. Blow out the hose to make sure it is clean. Reinstall the hose making sure you get it back on right at both the throttle body and the intercooler or you will get a leak.
5. Install Fuel and nitrous lines. If you ran the nitrous line to the right place you should be able to attach it to the solenoid with no problem. Make sure you attach it to the IN side and to the Nitrous solenoid. If you have filled your bottle, which you should have, make sure to purge the line before connecting it to the solenoid. If you have not filled your bottle go do it now as it will save you time from having to come back and do this later. All kinds of crap ends up in those lines and can block the tiny hole on the jets. To purge the line just get some one to hold the line with a towel facing away from anyone and turn the bottle on until nitrous flows freely through the line. Also before you do this make sure you have tightened the fitting on your bottle. Now run the fuel line from your fuel rail to the solenoid. If you have the 03 fuel rail use a puller to remove the schrader valve and then thread in the appropriate sized AN fitting. I cant tell you what size as different companies use different sized fittings. If you dont have a fitting and dont have someone there that carries them you can get it from the people you bought your kit from or from Godman high performance
www.godmanhiperformance.com. They also will make you any kind of fitting or line you want for a great price, (no I dont work there but they are local and have been very nice to me. They wont treat you like an idiot even if you have no idea what you are talking about.) Now attach the line from the rail to the solenoid. Make sure you attach it to the IN side and to the FUEL solenoid.
6 Install lines from the Solenoids to the Nozel. Before you attach the lines from the "out" side of the solenoids to the nozel you have to put the jets in the nozel. Follow the recomendations of the manufacturer. If they did not come with a recomendation go to there web site and they will have a jet calculator. I would not start with over 35 hp though. Make sure you put the Nitrous jet on the Nitorus side and the Fuel jet on the Fuel side. Now attach the line from the "out" side of the Fuel to the fuel side of the nozel. Connect the "out" side of the Nitorous to the Nitrous side of the nozel. Make sure all the connections are good and tight. Now place the airbox in to make sure it fits properly. You may have to adjust the solenoids to the left or right to make it fit perfect. Once you have the solenoid placement down remove the air box and tighten the bolt holding the solenoids.
7. Electrical install. If you have a relay it should have four wires. A ground, power wire, wire to power side of solenoids, and a switched wire. You can place the relay on the far right side of the engine compartment just to the rear right side of where the airbox is and where the air box has a pipe into the fender well. There is a large screw there. Just remove and attach the relay there. You may have to move it a bit to get the hard pipe from the airbox there but it will fit. Now take one wire from each solenoid (if they have a positive and a negative side labeled use the power wires) and connect them to the wire on the relay labeled to go to the solenoids. If you have to use extra wire to make them reach use at least 10 or 12 gauge wire. I personaly would soldier them together and then use the heat shrink wrap tubing on top of that. You could also use male female connectors and then wrap them with the tubing or electrical tape. Take the other two wires on the solenoids and ground them to the battery tray where you connected the solenoid bracket. Make sure you scuff the paint on the tray so you get a good ground source. Now run a 10 gauge wire from the power wire on the relay directly to the battery. Again use the proper sized connector and run it far enough down, away from heat, and run it up the back of the positive power cable. The red cover will hide it. Again I am assuming that you are running the wires in the engine compartment away from all heat sources but where they can not be seen. It would be a good idea to use an inline 30amp fuse to all wires you run directly to the battery. They can either be fusable links or just the regular type fuses.
Now is the hard part. You need to run four wires into the engine compartment. You can use 10 or 12 gauge wire for all three, but one can be smaller if you want. The best place to get them through is through the rubber grommet where all the other wires come through. If you remove the covering on the drivers side under the steering wheel this is much easier. Just feel around under there and you will find it. I have found no easy way to do this so just get at it and it can be done. Make sure you run enough wire. I would rather have way to much than not enough. Once you get them through one is going to go directly to the battery. Again use the correct fitting and you can attach it to the bolt on the left side of the battery terminal. This should be a 10 or 12 gauge wire and a fuse here would be a good idea too. Also again you can hide this wire by running it through the red battery terminal cover. This will be the power wire to your arming switch if you are using a wot switch it will go there. Place the wot switch where when you floor it it will activate the switch. I have seen these get bent and stuck open so I dont use one. Attach the power wire to one side of the WOT switch and attach another to the other side. Run this behind the dash over to the center console. Remove the 6 screws holding down the center console and run the power wire under it up to the center storage compartment. Remove the little carrier in the compartment by removing the 4 screws holding it in and drill a hole the right size and attach your arming switch inside there. You may have to use a dremmel to remove some plastic in the center console to fit the compartment back in but it cannot be seen. Attach the power wire to the arming switch after you get the compartment back in the console. Then attach one of the other wires you ran through the engine compartment from the other side of the arming switch to the switched wire on the relay.
Now to the MSD window switch. I put mine in the compartment below the stereo. Just drill a hole in the back big enough to fit the wires through. Attach the yellow wire on the msd switch to the ground wire on your relay. Attach the last wire you ran from the white wire on the msd box(signal input) to the Blue/Tan wire on the ignition coil. You can either remove the wire from the harness and graft it in if you have the proper tool, or you can remove a very small amount of the plastic covering on the wire and slodier the wire to it and then just cover it with electrical wire. If you do it right it will look like it came that way from the factory. This is the only wire that you cant really hide completly. Now attach the black wire on the MSD box to a good ground source. Basically just remove any screw that is in metal and put a fitting on it and screw it back in. Take the red wire and run it to the fuse box and piggyback one of the fuses or just strip the cigarette lighter wire a bit and soldier it there. It draws very little amperage so even with both in use it wont blow. You just want to make sure that you wire it to a source that doesnt have power when the car is off. Now the last wire on the MSD box is the gray wire. Just tape the end up so it doesnt find a ground source and hide all the wires. Put everything back together. Start the car up and make sure there are no fuel leaks. Set the MSD box at 2 cylinder odd and make sure it is reading properly. Turn the car off and turn the nitrous bottle on. Listen for leaks both at the front and back. If there are any leaks fix them. Turn the nitrous bottle off.
Now get a buddy and set the msd box to have the solenoids come on at 1500 rpms and off at 2000 rpms. You have the nitrous off again right? Now if you have a full throttle switch set something on it to make it stay in the open position. Now with your buddy reving the car listen for the solenoids to kick on and off. Make sure they come on at 1500 and off at 2000. You should be able to hear them if you dont have an aftermarket exaust. If you do use a mechanics stethoscope and set it on the solenoids and listen for them coming on and off. Your car will get fuel at this point but if you have only set it up for 35 hp it wont be enough fuel to bog the car down. If all is well check the bottle to make sure you have at least 900psi of pressure. If you dont heat it up with a blow dryer or something other than a torch. If you do turn the bottle on and go to the track
and try your new found horsepower out.
Oh yeah I forgot, make sure you set your MSD box back to at least 3000 rpm cut on and at least 6200 cutoff before you actually run the nitrous.
If I left something out tell me as this was a very long post and a step would have been very easy to miss.
http://photobucket.com/albums/f374/kday2477/
For those that dont want to buy a new fuel rail there is a write up on how another member T'd into a fuel line. You have to scroll way down to post number 12 I believe. The best way is to buy a new rail, but this is another option and is much cheaper. Just make sure you do it right. If you mess up and the line spews gas all over the engine it will be a $20,000 mistake.
Nitrous FAQ (sticky maybe?)
Hayabusa
