While I thought about continuing the "Anybody Got NOS" thread, that was Spidey'* and I didn't want to be accused of hi-jacking it, so here goes my installation of Nitrous Oxide on my 1990 Boneville LE.

I'm starting at the rear of the car and working my way forward day by day. I'm also doing this on a tight budget, so some of the things shown may not seem logical, but they are if you skew your viewpoint to the least expensive solution.

Ok, here we go with Day 1 and installing the bottle in the trunk along with the feed line to the engine compartment.

I removed the carpet, padding, jack box, and spare tire from the trunk. The bottle needs to be mounted on the passenger side of the trunk (to balance out the weight from the driver) with the valve end facing the front of the car. Here'* a picture of the trunk:



From the photo you can see the two parallel beads pressed into the floor of the trunk, They correspond to the frame rail on the underside of the trunk that supports the bumper (see my trailer hitch thread for a photo of that frame rail.) You can also make out the spot welds on either side of the frame rail. That'* my aim point for drilling the bottle mounting holes. That way, I'm going through both pieces of sheetmetal. On the outboard side, I'll need to back up the bolts with nuts and washers since they will only be going through one piece of sheetmetal.

The -4 AN to -4 AN bulkhead fitting needs to pass through the body and run along the underside of the car. (This is a safety issue, you never run fuel or NOS lines inside the body of the car...unless you want the fire risk of an oxygen rich enviroment right where you just happen to be sitting ) Note the circled area with the two pressed beads in the trunk floor. That is the perfect spot to pass the line through the trunk. Just in front of it is an electrical connector grommet passing through the trunk, just behind it and you hit the frame rail that connects the lower suspension together. Drill a 3/8" hole between the two beads and you will come out in a little open area behind the fuel tank.

With the holes drilled, I cut a 60" length of steel 1/4" tubing and installed 45degree -4 AN flare nuts & sleeves on them. On one end, I installed the bulkhead fitting and bent the tube with a 120 follwed by an 30 in the opposite direction. I used a tubing bender for these tight turns. I'll try to get a picture of this under the car later, but the gist of it is I want to come through the trunk floor, then hang a left and follow the underside of the trunk floor across the width of the car. That brings the feed line over to the driver'* side frame rail, which it can follow down to where all the other fuel, vent, and e-brake lines are running. I hand bent the gentle 90degree turn at the driver'* side rear of the fuel tank. That let me run the lines without having to drop the fuel tank on the car. A second line from the front of the car will meet up to this line with a -4 AN male union connector. That will give me a solid steel feed line from the trunk to the engine compartment where I can switch to a braided line to the filter and solenoid.

Here'* the same trunk with all the carpet back in, bottle mounts bolted down, and the bulkhead fitting in place. Tightening down the bulkhead fitting is the only two-person job, only because somebody had to be under the car holding the fitting with a wrench while somebody sitting in the trunk tightened the nut. In my case, my 13 year old daughter Carolyn did the honors in the trunk while I was under the car. She also did the locating and cutting of the holes in the carpet and backing for me.




As you can see, the bottle hose is a little too short. No worries, it actually belongs to my 87 Camaro. I need to measure one up and have it made on Monday to finish this connection.

Here'* the first of the "Go Cheap" notes: I used steel tubing because it is far cheaper than using braided high-pressure hose. You are looking at roughly 12 feet worth to get from the trunk to the engine bay. I though about using stainless steel tubing, but on the recomendation of the fellow at Florida Hydraulic, plain steel was the way to go in terms of over-all strength and ease of which you can work with it. Same goes for the AN fittings. I had a choice of Anodized aluminum or steel. Again, steel was the way to go (Stronger joints and cheaper too.) Cost $10 for all the steel tube and fittings vs. roughly $90 for stainless braided/teflon hose with AN fittings on them.

Step two begins this evening with bending the rest of the steel tubing for under the body to the engine compartment and fabricating a bracket for the NOS and Fuel solenoids.

Moved to Forced Induction:

I am so sorry for not knowing this but what does the "-4 AN" refer to?

Oh, sorry. It'* a special type of flared pipe fitting. The "AN" came from Army Navy as they were the first to use it (1930'* ?) It'* a common fitting for hydraulic and high pressure hoses.

Note There are really two styles of AN fittings out there. "Real" AN fittings are for aircraft use and have a shallower angle on the tubing flare, which is even stronger. They are also more expensive. Most hose fittings used by everybody else are Automotive AN fittings and have a 45degree flare to the tubing. Nearly every AN fitting you need is the automotive style. You can get them from Aeroquip dealers, also from Speed shops under the Russell, Earl'*, etc. brand names.

The dash numbers correspond to the diameter of the tubing they are mean to join together in 16th of an inch sizes. So, a -4 AN is meant to be used with 4/16th tubing (or 1/4") If you want a good look at a -4 AN flare, go unscrew the plastic cap off your car'* fuel injector rail test port. That is a -4 AN male with a schraeder valve screwed in the middle of it. If you car has an R-12 style system, then both the high and low pressure ports are also -4AN male fittings.

Nitrous Oxide bottle pressures are around 1000psi. So you need good fittings. Steel tubing (or braided hose) with AN fittings is the ticket. The only two sizes of AN fittings needed for NOS are -4 and -3. All the plumbing up to the solenoids for both fuel and NOS are -4 AN, all the fittings from the solenoids to the jets/nozzles are -3 AN and use 3/16th inch tubing. Here'* a picture of this stuff:



Here you see a NOS Fogger next to a Nickle to give you a sense of scale. The top feed line in the picture is a pre-made, stainless braided -3AN hose. The bottom feed line shows the flared steel tube with the -3AN nut and ferrule, a #22 NOS Jet, and also a -4AN Nut and ferrule. The way nitrous systems work, the jets are shaped like the end of a -3AN male fitting and plug into the nozzles or spray bars, then the -3AN line is connected to it to form the finished high pressure connection.

Thanks, that'* much better. I can't wait till you are done. The more I watch and learn the more I think I can do this myself!

sorry to bring this up but I was wondering if there was any update.

Not really, been working fine for a few months. During the meet back in October, one of the other BC members posted pictures of the finished installation, so I never came back to this thread.

glad to here that it is working fine. thought you fell off the face of the earth for a while. what did it do for you speed and time wise and have the plugs, pistons,etc held up? :o

I haven't had any issues with it. No timeslips for it though, as it hasn't made the trip down to Bithlo yet. Just a few WOT runs on the backroads. The initial jet selection looks like it'* right on (gee, that rarely ever happens) so, while Ive tried it with richer and leaner fuel jets, the 30/22 combination seems to produce the best mixture.

Never did get to wire a WOT switch on to the TB, I've been using just a temporary pushbutton to activate it. (I plug it into a spade connector at the solenoid valves, run it out from under the hood at the cowl, and into the driver-side window...kinda cheesy, but it does the job for the moment.)