THE NITROZ INJECTION PROJECT
This page describes the installation of a Nitrous Injection System to Mr.7/11's Katana. It is not intended to be a step-by-step guide how to build or/and install your own nitrous system because Burgerman @ WWW.NITROUS.INFO already did a great job of explaining everything you need to know on the subject.

A bit of history...

It all started when Dave of UK-based HM Racing donated most parts of a TMC HighPower Nitrous kit for use on my 7/11. He'd only give it to me if I swore on my mother's grave (who is still alive and kicking anyway ;-) that I'd actually plumb it in. Easier said and done because I was missing one critical part aka. foggers. As it turned out after fitting Dave's Mikuni RS carbs to my bike it gave more power than I'd ever get used to anyway so nightmares of the bike flipping over after hitting the nitrous button in top gear became more regular to the point where I decided to cancel my plans. Besides I wouldn't know where to mount the bottle.

It was after getting my Katana that thoughts about the nitrous injection started to creep back into my mind again, and after reading on Burgerman's pages that I didn't need any special foggers anyway because the TMC solenoids have jets fitted I became enthusiastic about the whole idea again.

My aim is to create a reliable gravity fed system with as little parts as possible giving anywhere between 25 and 45hp extra. Reliable in my eyes means as little parts as possible, so all the "optional stuff" like pressure gauges and fuel pump will be left out. The only thing I will be adding is a progressive controller to gently feed the nitrous to the 20-year old engine.


What parts do I basically need?
- Nitrous bottle
- Fuel and Nitrous solenoids
- Distribution Block
- Injectors
- Activation switch on carbs
- Arming Switch
- Warning light
- high-flow fueltap
- Fuel pump
- Progressive controller

The parts donated by Dave.

Distribution Block
The easiest way would be to select a 4 into 1 push-lock fitting but Festo doesn't carry them with the same diameters on both ends. Only 6mm into 4x 4mm. So I chose a distrubution block with 1/8" male thread that screws into a 1/8" female push-lock.

Pneumatic Push-Lock fittings needed.

Injectors
My biggest problem was the missing injectors or better put the cash to buy them. I said was, because I recently discovered I didn't need foggers because my system is jetted at the solenoids and so I can use some basic injection points.
I will use M5 push-lock fittings that are screwed into the Katana intakes' carb synchronization holes to provide the extra fuel, and drill the intake rubbers to fit the same but slightly modified push-lock fittings as shown on the diagram.

Burgerman wrote; "Solder a short brass tube into the nitrous fitting, with hole or slot cut into it near the (blocked off - solder) end, so the nitrous goes down the
port towards the engine and collects the fuel on the way.

If you add fuel at the carb balance points, also add a short straight bit of brass tube (soldered in) so as to prevent the fuel clinging to the port
walls, as it will not be atomised properly otherwise! Meaning that it will effectively go through the motor untouched so it will burn lean which is bad."

Activation switches
Instead of using a conventional microswitch to sense if the throttle has fully opened I will try to implement some very trick "inductive proximity sensor " if I will be able to make them work reliably. These are sensors that are able to "see" if there's a piece of metal dangling in front of them. The future will tell.

Sensors are XS4P12PA340 which means;
- 4mm nominal sensing distance
- 10-38V voltage range
- max. load 200mA (this means I need a relay which coils consume less than 200mA)

Here's a movie of me testing the sensor (1.9MB .AVI)
The movie uses motion-jpeg compression and so is best viewed using the Apple Quicktime player.

The sensor is connected to a battery...


...and activating the relais as I hold a metal object in front of it.

Proximity sensor

Nitrous controller

The reason we need a nitrous controller is to make the extra power come in gently. This keeps the initial load on the engine down and helps prevent sudden wheelies/wheelspin.
The circuit to realise this very simple and based around a 555 timer IC.

This gets close to what I'm looking for...