I finally got around to completing my Zex wet nitrous system on my 01 AE 5spd, but before I spray I need to know when I should activate the N20. I have an autometer air/fuel ratio gauge and whenever I change gears it indicates that I run extremely lean to the point where I can't see the leds. Of course as the speed and rpms rise I start getting into the stoich and eventually rich area of the gauge depending how fast I'm going. Should I start spraying at 2nd gear above 3k rpm? Then shut the n20 off when I'm about to shift again then activate it again on the next gear? Or should I just shift through gears? If it helps: I installed both the Sards FPR and Walbro 255 fuel pump and raised the fp to 3 psi higher than stock. Thanks to all!

 

i don't qualify as a 5th gen/5spd owner, but i have a ZEX wet kit and one of those autometer air/fuel ratio gagues mainly for track purposes with nitrous so i maybe if something goes wrong i can save my engine lol. I could be wrong but if you're WOT (with nitrous on or not) your guage should be in the green. When you get off the gas to shift gears it should shoot all the way counterclockwise into the red and go dim for that brief period of time when you are off the gas. Then when you let the clutch out and go WOT again, it'll shoot back to the green. Fun to watch lol.

i wouldn't advocate trying to turn it on/off before/after every shift you're gonna waste a lot of time that you would be burning nitrous and extra fuel! I'd just leave it on all the time.. and you can activate it earlier than 3000 rpms in 2nd gear too, unless you were getting really really bad wheel spin and don't want to.

 

Okay first off, that Autometer A/F gauge, unless it is connected to a wideband, is useless. The stock O2 sensors only read in narrow band, basically from 14.0-15.5 or so, they are only there to tell the ecu to add or subtract fuel, and are not very accurate. Really only serves as a lightshow. You should have a fuel pressure gauge, and an EGT at a minimum, or a fuel pressure gauge and a wideband A/F gauge, like the LM-1 or Zeitronix. You should also have a window switch, to prevent you from hitting your RPM fuel cut and blowing your motor. It's fine to spray in 2nd gear on, 1st gear and your probably just gonna get wheel spin on the 5spd. When you let off the gas to shift, the nitrous spray should cut off anyway. If you are power shifting on nitrous, you are looking to buy a new transmission soon. Again, without the proper gauges, there is no way to tell if you are too rich or too lean. You also need to pull your plugs to check for signs of detonation.

 

Thanks a lot for all that helpful info.