After searching the archives on several 420a related boards I have a few questions about my future nitrous setup. I am 99% sure I am getting a Zex Wet kit with some type of RPM Window switch (for safety).

Engine Mods:
-CAI, OBX Header, 2.5 Custom Catback, Testpipe, AFX UDP
-Headerwork: Ported, Crane #16 cams w\springs, oversized valves, PT lifters, AEM cam gears
-AFX ECU (ordered 5 weeks ago)
-JeepTB

Drive Train:
-Spec Stage III Clutch w\SS line
-Custom LSD Insert w/machine spider gears

Now my problem is fuel and bottom end are STOCK. The questions I have are:

What are the biggest injectors the stock ECU can handle and idle correctly (24lb?30lb?)?
I will probably be getting a custom intake manifold before the year is over with and would like to replace my 130k mile old injectors and the fuel rail too. Would new injectors and a fuel pump rewire be good enough for a 75 wet shot???

And since I blow through first gear real quick, I guess at the track I should spray when I shift into 2nd, to keep from bouncing off the revlimiter and blowing my motor. If I spray when I get in second is a 75shot going to break the wheels loose?

I know the AFX adds timing and I can switch back to stocker if I need to.

Can someone post their nitrous times at the track?

Um i dont think that ZEX makes a wet kit. the ZEX kit pulses the fuel injectors to add more fuel rather than dump it throught the nozzle and into the intake manifold. Youll be fine running a 75 shot on a stock bottom end just make sure your compression numbers are good. And do a search for more info there is tons to be read here on 2gnt about n2o.

I already did a search and i was left with those questions. Zex does make a wet kit and they have been doing it for a while now.

Why do you want to replace your injectors? Running a 75 shot doesnt need any larger injector than the stock ones... If you get larger than stock injectors then you will have to tune your car to be able to just drive it as a daily driver. If anything get plugs, do the fuel pump rewire, and get a walbro. That should be all you need, at least it has for me and I am spraying a 75.

-Chris b.

From what i understand the ZEX kit just pulses the injectors more when spraying to get more fuel. I wouldnt get bigger injectors because you will be running way rich and when you spray it might be way too much fuel causing you to bog down.

I am sure Zex has a wet kit that uses a special nozzle to shoot the nitrous and gas into the intake stream.

Will all of the headwork done and other supporting mods + 75 shot of nitrous I would think the stock injectors would be getting kinda tired, especially since they have 130k miles and I am constanly on E (trash in gas tank).

You will not need injectors for that setup, trust me, you wanna run rich and slow your car down, then put new ones in. You come to a board and ask for advice and then argue when you get it. Not a good way to do it if you want more lol. stick with the stockers or buy some stock replacement venom injectors. Dont' buy bigger. N2O wet kits supply there on additional fuel, you don't need more injector. As for headwork, it is most likely not flowing in the slightest bit more. Do you know how well a 420A head flows stock? If it needed head work, then Hahn would not be running 10's on stock head and cams.

^^^ Word.

you're setup right now (as to your car's mods so far) look good. you should see excellent gains from your nitrous system if you don't go overboard on the gas and get bigger injectors and all these fuel system mods. the fuel pump rewire or a better flowing pump should be the extent of your fuel system mods when running a 75 shot.

the only thing i would look into replacing is the LSD. it could potentially blow up and destroy your transmission, possibly more. check the manual transmission for in the engine/performance forum for pics and more info.

I agree. Stock injectors are good enough for 75 shot. I ran an 80 shot with stock fuel system for over a year. Upgraded pump is a good idea, as also mentioned above...and yes, Zex does make a wet kit. The kit that pulses the injectors is the dry kit. Not DSM friendly.