I've been running a universal NOS wet kit for a little while now. My fuel tap is via the SPX adapter, using the standard 1 foot line from the SPX tap to the fuel solenoid. What I noticed is if I haven't used the nitrous for a while, the very *first* time I hit it the car would "bog" for a fraction of a second - almost fall on it's face - then take off like nuts. After that initial hit there was no problem, always instant power immediately. I thought maybe I needed a nitrous line "purge" due to air in the line, so I bought one. Well, that didn't solve the problem, in fact it seemed to make it worse!

So I finally theorized it must be the fuel line - perhaps air gets in the line after the car is shut off, etc. and fuel pressure leaks down. Honestly I'm still not sure. But I removed my nitrous purge, and hooked my purge button up to the fuel solenoid instead. Now I hit it to purge the fuel for a moment before using the nitrous for the first time (which no doubt injects a little extra fuel in the intake, just making it run rich for a moment, but no biggie). Solved the problem completely. I can only suspect I was shooting straight nitrous in the intake with no fuel for just a fraction of a second. Very dangerous, but I think it ran SO lean it probably misfired horribly, because based on my calculation a 125hp shot at 4000 rpm with no fuel would put it so lean it would be like 18-19:1 which I've heard is so lean cars just misfire.

Any questions/comments? Anyone else with nitrous notice the above?

 

I think I would be pulling my plugs, especially 6 bro just for peace of mind. Runs fine right? Have you ever run a pressure check on your entire N20 system? It's only 40 bucks, I reccomend it to look for leaks etc. Once you know all your lines are right and their are no leaks it's easier to trouble shoot. So do those things above.

 

Very interesting... in my case I always clean the nitrous line and the car response very nice... but is not less what you did... the car is running fine doing that just keep up doing it!

 

You were real lean with no fuel then made a switch to be real rich? I will play Devil's Advocate and say there has to be a better way to play.

 

18-19:1 wont make you misfire...But you will be mopping up oil with chunks of VQ35 engine in it...

Are you using a WOT switch?if so I suggest a window switch..I wouldnt purge fuel into the intake if I were you!!!

 

all this purging fuel business is making me nervous. are we on crack?

i think he's purging fuel out of his car which is still bad, but if your really purging into ur intake, your asking for trouble. specially at a 125 shot (that a lot of extra fuel). damn...that gave me the chills just thinking about it.

since we're on the subject of a feta cheese style vq35 engine salad, what would be considered dangerously lean? 14:1? 15:1?

a good a/f ratio would be ne where in the mid to upper 12's correct?

 

Please - I'm not spraying fuel out the car like a nitrous purge. Not only would that be environmentally irresponsible, but dangerous. I am activating the fuel solenoid for just a BLIP, fraction of the second. A little extra fuel sprays in, which makes it run rich for an instant, no harm done.

 

mid to high 12's are good on NA..But forced induction I would stay mid 11's maybee 12.0 most..