"I think Dry [more safe!]
I don't think so. Let me tell you why.
I've run wet systems (single fogger first, now a direct-port setup) on my '93 for over a year now, with 106 dragstrip passes made.
The dry systems, I do agree to a point, are very safe and reliable. However
, they do have their limitations, especially when it comes to adding the requisite fuel. Without modding the ECU at all, a 50 shot dry setup should be just fine. The O2 sensor can pick up on the added oxygen in the exhaust stream and increase the fuel flow through the injectors just fine. At less than a 100-shot, IMHO, the stock (259cc) injectors will be maxxed out, unable to supply the fuel the engine needs PLUS the added fuel needed by the increased oxygen levels from the nitrous.
Now, with a direct-port setup like I've got, the fuel is shot right past the injectors, through the fogger nozzles. Yes, it does draw from the same pressurized line that the injectors get their fuel from. And this is where the ability to run more than a 100 shot gets easier with a wet system: By merely adding a 300ZX TT fuel pump (or similar high-flowing unit), the ability to use a 100 shot or higher becomes much easier than with the dry setup.
With the dry setup, in order to run a 100 shot (like the JWT setup -- a great setup regardless), you need: JWT ECU (ain't cheap), and 370cc injectors (or bigger), and they ain't cheap either. You're looking at at least $1,000 for that setup, minimum.
300ZX TT fuel pumps (or similar) go in the $200-250 range, last time I checked. By merely making that mod, and adding a FP regulator, one can increase the nitrous flow to a much higher level, and safely. The stock injectors have no clue what's happening: They merely see the O2 signal as being pretty much spot-on, and adjust minutely, just like in everyday driving.
The trick to direct-port wet setups is: Fuel pressure and management. It took quite a while to get my setup working *just* right (playing around with different F jets, etc.).
But once we sorted it out
, the thing is now easily adjustable, and can be increased in a matter of minutes. Each cylinder is now getting *precisely* the same metered amount of nitrous, whereas with the dry setup, things probably aren't so evenly mixed.
So, to make this long post even longer...wet setups (especially direct port) offer much more 'tune-ability' at a lower cost (JWT ECU/injectors $ vs. 300ZX fuel pump $), and you can run much bigger shots, or smaller ones, at will by merely changing the jetting.
Just my long, humble opinion
, '93 SE-R w/ 149,000 miles, JWT pop, header, ProActive
clutch, ST bar, NOS direct-port 75hp, Autopower 4-point roll bar/harnesses.
1/4 mile, [email protected] 1/8 mile, 1.98 60-ft.
My SE-R page, with videos