I've seen alot of posts about wet kits and don't understand why. Even the stock injectors push out alot of excess, unused fuel. There's plenty of fuel for a dry shot of NOS without upgrading anything. But with any NOS setup, feel it out, don't overdo it. I'm getting a dry kit of 50 shot and injecting it directly into my intake. And it should work like a charm.

 

You use a wet kit so that you can tune the air fuel ratio yourself. I'm not sure what the fuel pressure is in these cars but you don't necessarily need another fuel pump. I would never personally use a dry kit because adding oxygen with no fuel means running more lean which means boom. I would also never use the nitrous that just goes off with a push of a button. You should use a WOT switch with a window switch so that you only shoot between certain rpms to help protect your engine (If you accidentally hit the rev limiter, you don't want it constantly shooting up there). Also, get a fuel pressure safety switch so that you don't have to worry bout shooting when theres not enough fuel pressure to prevent from going lean again. You can put the arming switch anywhere inside so that it doesn't always shoot at wot. You'll mess up the solenoids if your trying to shoot with nothing going through. YOu'll want a bottle heater to keep the pressure up. I'd start with a 50 shot, make sure the afr is around 13.5. And then slowly move the shots up as you tune it to make sure your good.

 

I just noticed this thread when I was posting questions about the TII differential in this section.
I ran a wet 50 shot "NOS" brand kit on my FD for awhile with good results. I'm actually selling it now with a new bottle if anyone is interested. I used a full throttle switch, and an arming switch that was mounted on the steering column. It was easily accessible during a race.

You can use nitrous for around 12 seconds at a time, You can use it at lower RPMs provided the engine can easily rev. (don't use it at low rpms in 5th gear for instance) The 3rd gen fuel pumps react greatly from rewiring them, if the 2nd gens are the same way I highly recommend rewiring the pump to get good voltage to it. A fuel pump upgrade might be needed depending on how much extra HP you're looking for or if you're already close to maxing it out. I personally feel a wet kit is a much safer way to add nitrous. It also requires no extra fuel from the injectors which seem to easily be maxed out after several mods. Then if you have dirty injectors you don't have to worry about the fuel supply being less then adequate. I think 100 shot is about max I would go on a rotary.

 

I've gone through about 15 bottles, runs like a charm.

I tested 100 shot jets for about 1/8th of a bottle but at high rpm in 4th gear it detonated a bit so I got rid of that real quick

75shot dry is perfect for mine!

 

I agree also with using a dry shot, is there a reasoning behind you using it instead of wet. Bc I was instructed to use dry for the fact that the stock fuel system already runs rich and can use the excess fuel with the dry shot. I was just seeing if there's other reasonings why dry would be a better option to wet for cars like ours. Also I have a full bridgeport so there's plenty of extra unused fuel.

 

Here is the deal with the dry shot, and stock fuel system. You can run as much nitrous as you want dry, making sure you have enough fuel to support it. meaning you will have to tune your ECU to provide that extra needed fuel... The stock ecu don't know when the nitrous is arm, so you will basically will have to run all that extra fuel off the nitrous... thus making your car run like crap while not on it. (this is on Rtek or stock ecu equivalent), while on the wet kit, fuel enrichment has nothing to do with the injectors, you dont need any piggyback or what ever, just change jets...
As for a second pump, if you want to avoid that, get a dual port FPR... but that will run you $150 minimum if you got a bunch of used stuff, while the a second fuel pump in the tank will not be more than $60.

The point it don't ever share your stock fuel pressure with the nitrous kit, all you doing it bypassing fuel from the rail and shooting it through the jets, the jets will not be spraying the correct fuel.

 

Im liking all this input keep it coming, 1st hand info about nitrous/rx7s is sorta scarce.

 

ya i sprayed my S4 N/A. 75 shot wet NOS system. only did it 2 times first time it backfired and broke my MAF sensor and the 2nd time it took out the engine... but MAN was if fast when it worked. reason my engine died to was bacause it was allreddy low on compression and i didnt know. nitrous will find a flaw in a engine really fast. so as long as your engine is in good order go to town!!

btw im selling my kit bottle warmer, gauge, ect pm me if ya are interested.