Q. How is the nitrous package fitted on ZX7. I mean where have you put the nozzles etc. Do you have the airbox still on the carbs or not?
A. First of all, I would never run a street bike with out a airfilter, so yes I do keep the airbox. I mount the nitrous nozzles into the head by drilling (I CAN HEAR EVERYBODY GROANING NOW) into the lower or bottom side of the intake ports. Now in order to do this without removing the head, you must purchase a 90 degree drill. Make certain to stuff a oily rag down into the ports to catch chips, then use a vacuum to suck out the mess. Done 5 like this never been a problem. I go into the floor of the port as this is were airflow is the most laziest and has least effect on normal flow, as well as the only place they will actually fit. If you later remove the nitrous, they sell metal plugs that screw into the holes. This is the best place to put the nozzles for several reasons.
1. The closer to the intake valve, the better. The moment that nitrous exits the nozzle it starts to expand into a gaseous state. The greater the amount of liquid into the motor versus gaseous improves performance.
2. I would never inject nitrous through carbs, as the sub freezing gas at 127 degrees below zero can cause embrittlement of the slide needle and its eventual breakup. Also you are getting further away from the intake valve.
Make no mistake about it, Nitrous is not something to be taken lightly.
Q. hey ken I check on kit and they are all fogger kits if I use the plate would they interfere with me using the air box or will it just take up the slack in the rubber? also what would I do for fuel? just split into the fuel line from the pump to the carbs or would it be better to just work the petcock and run it off the reserve line and not have reserve? I would really like to put nitrous on my bike I have it on my race car and I seen what it can do too performance and I like it. also can I retard my time with a kit I have seen that they have advance kits do they work just the opposite?
A. There are no plate kits for motorcycles. The fogger nozzles do have rubber boot mounts but the mounts are to big for ZX7s. I have been able to use them on GSXRs, but not on ZX7s.You will have to drill into the head. Its not that hairy really as the kit comes with the proper size tap to cut the threads. I suggest that you T off the reserve line, this doesn’t effect normal operations if you run out of gas in ON, and keeps the nitrous fuel pump from running out of available fuel as long as there is sufficient gas for operating in the on position.
You don’t want to run out off GAS with nitrous on!!!
I use to run a adjustable advancer set with -2 degrees retard, however my bike always like +4 with the stock ignition under normal operations, so this was a compromise.
I now use a DYNA 2000, though I’m not totally happy with it. It does allow you to use full timing under normal operations then gives a pre-set amount of retard the moment you go to the gas, -4,-8,-12-,-16 degrees.
On a ZX11 I built, I found best timing at 35 degrees, and most power with the nitrous at -12 degrees, of retard. Each time I retarded the timing nitrous power continued to pick up. Nitrous HATES advanced timing as it burns so much faster, it doesn’t need a lot of advance.
As somewhat disappointed as I am with the DYNA 2000, its the perfect compliment to a nitrous bike.