Well guys My N/A days are over. I just installed a ZEX wet kit and took it for a spin. It definatly pulls a little stronger. However I am having a problem. I am running extremely rich. I have the largest N2O jet in and the smallest fuel jet in and I am still topping out the Air/fuel guage on the rich side. I am considering ordering a few larger N2O jets from Zex to see if I can lean it out a little. What do you guys think who have experience in this?? Thanks.

 

What kind of A/F ratio gauge are going by? Is it a wideband o2? If not then I would definitely not go changing jets to lean it out based on that...you are going to end up with a blown motor.

 

I really suggest you call zex up and ask them what are the correct size jets for the shot that you want. I wouldnt play around with mix matching jets. and becarefull about running very rich because you might risk causing an intake backfire if your intakemanifold gets flooded.

 

do not play around with the jets, put exactly the pill they say put and leave it be. of course your gonna run richer because you have introduced nitrous. you sure dont wanna go lean.

 

also, most likely your bottle pressure is very low therefore causing you to run rich, so if you dont have a pressure gauge get it asap and dont spray anymore till then. and plus, untuned with nitrous = very rich like most of us so dont worry just make sure ur bottle pressure is in the 900range

 

An intake backfire is actaully caused from the nitrous reaching the cyl. first (super lean!). There's other reasons too but beeing richer then normal isn't one of them.

If your down in the 12-11 on the afr you're ready to rock, that's
not too rich for nitrous.

 

exactly i believe this is his problem. your probably low on pressure and not getting the full shot of nitrous. first make sure bottle is full and heated to the correct temp and use the jets they recommend.

 

No, Nitrous backfire "can" be from running extremly lean, but its more common with having too much fuel being sprayed and therefore causing the fuel to puddle up before the intake valves, the fuel gets ignited causing the backfire.

 

I would suggest you follow the chart in the stickies. Do not make your own combo for jets or BOOM. As for your gauge unless it is a wideband the gauge is useless(do not listen to the gauge the gauge lies to confuse). I say get your bottle pressure up and try again with the correct jets.

 

and if you managed to actually hit 14.08@99, with 75 shot you should be in mid to almost low 13's!

 

Fuel get's ignited BECAUSE of the backfire caused by being too
lean. Why would th fuel burn for no reason?
It's not just being too lean that makes backfires but it's NOT because
of over fueling.
Doesn't even make sense.

 

^ That's correct. Running lean will cause the nitrous backfire.

Curt, some things to keep in mind, and to keep your car safe......
Don't spray with 1/4 tank of gas or less.
Don't spray into the rev limiter, you probably want to get a window switch in the near future.
Don't spray in 4th or 5th gear. You want to spray in the lower gears that will get your rpms up there faster.
When you've been spraying and your car starts to bog or not really have an effect from the nitrous, usually means your bottle is almost dry. The only jet that's pushing much of anything out of it is your fuel jet, meaning you're running really rich with the extra fuel. Check your pressure gauge, but mine sometimes read 800+ from just the pressure that was inside the bottle, and there was hardly anything in it.
The air/fuel meter (techno display) will not tell you much of anything when it comes to nitrous like already mentioned, shouldn't really go off that.

Nitrous provides a great driving experience, and with the use of safety precautions, it saves tons of headaches. Zex has a chart with the jets you need for the shot you want. You want to strictly go off that chart and use those measurements. If you use any other than what that chart says, you're going to run into some major issues. Ask more questions, we can help if you need it. Better now, then to switch to the All Motor forum and ask them how to replace an engine.

 

wow thanks for all the help guys...I had the bottle heated to 1000psi and when I would launch froma stop it would bog really bad I guessed it was from the unusually rich mixture. . So I should definatly not use the A/F guage? When spraying I really couldnt tell that the car was any faster, should you be able to feel a 75 shot? I only sprayed for a bout 90 seconds total in my venture out today so Im sure the bottle is no where near dry. I will call zex tomorrow and see what they recommend for jets. The only reason I changed the jets was because it says if you are running rich to adjust the jets accordingly.I think I may take the car back to rockingham this weekend to see if it shows up on the timeslips!

Any other suggestions would be greatly appreciated!!

 

For your wet kit, the jets are 40 Nitrous, and 21 Fuel. Last page of this pdf installation manual.

http://www.zex.com/Base/Instructions/ZEX132.pdf

That's for a 75 Shot. Also, you don't want to spray for a duration of more than 20 seconds at a time.

1000psi isn't too bad, but you should definately feel a 75 shot. Make sure you programmed the management unit correctly, and have tested at WOT with the nozzle not hooked into the tube and the system activated to see if it sprays a mist into the air. Probably need someone to hold the nozzle while you hit the gas. Car doesn't have to be running. If nothing comes out of the nozzle, you're connection is off somewhere or unit not programmed right.

Another note, you said that you bog. That means that all that is going into the intake manifold is fuel. Your nitrous is not spraying along with it. Your richness is bogging you down. That's what I was also referring to when your bottle runs out. That's the only time it should do that. Is your bottle open? Just checking. Your steel braided lines shouldn't be kinked. Are the lines hooked up correctly? Still seems like a programming issue though.

 

Ok I will double check everything tommorrow. Ill try and reprogram the box too to see if that helps any. Ill post back anything I find.

 

Im not sure thats right dude, what iv been told is what i said, that fuel puddles up in the manifold and gets ignited. Why would they warn so much about not spraying in really low RPM's? everytime they mention not spraying in low rpms they directly associate it with backfire.

 

Well you both are correct......

Q. What is nitrous backfire?
A. Nitrous backfires can be caused by two situations. 1. A nitrous system that is two rich or a system that atomizes the fuel poorly, thus causing pooling or puddling of fuel in the intake manifold. 2. A system that is operated too lean.

 

There!!!! lol now my questions is, its a given that it does get ignited but does that mean there is a spark before the intake valves close?

 

Missuderstanding?
A gas (nitrous) does not flow like a liquid (gasoline) so at low volacity,
Geuss what? The nitrous hits first, going lean. If you spray during a high
load situation and bog... BOOM!

The poor atomazation (puddleing) isn't the reason you back fire, but it's the reason crap goes BOOM.
You can even intake-backfire w/ a dry kit. Not as commen as a fogger because the fuel always get's to the cyl first via fuel injectors right at the valves. (I'm not saying a dry is better then single fogger)


There you have it.
It's not very clear but if you don't have good atomization fuel'll pool in the
manifold instead of flowing into the cyl. with the nitrous like it's sapposed to
possably causeing a backfire and igniting what's in the manifold, reasalting in an fire. (not like fast and furious but it's gets scary)

 

ALRIGHT.....well I figured out what the issue was. The cylinoids (sp?) weren't opening. I pulled the fuel pump fuse while idleing to ease fuel pressure and unhooked the fuel and n20 lines from the box. when I went WOT nothing sprayed out of the box. I reset the box and woosh it works. I am currently waiting for the bottle to warm up and Ill take it for another test run. Thanks Paramy for the idea to check the box. Are you coming to rockingham tomorrow night? I hear a few of the other charlotte guys are gonna be there.

 

Just got back from my first run spraying. I put all the correct jets in and went for a little ride. OH MY GOD!!! I am still shaking! It pulls so hard through the entire RPM range. I almost drove straight to CP for a dyno run....lol But thanks for all your help guys. I should be at rockingham tomorrow night to see how much time this will shave off my ET. I can't wait, and thanks again!!

 

Yea i knew something was wrong when you first said "it pulled a little harder", 75shot should be VERY noticible!! its awsome.

interesting, I never saw it that way nor did i ever read an explanation with that detail, but it makes sense. But i dont understand, when you bog wat exacly causes the explosion? like how does getting lean ignite the fuel?

 

I'm kinda messed up so my explination will
be crap but imagine you're in 4th at 1.5k and you floor it. It's not
going to accelerat any faster then when you give it half or quarter peddel for 1k rpms or two. That's called bogging. "dieseling" So you shot you're 75shot at a high load like that but you're engine can't move anyfaster so you're eingine get's
cramed with this nitrous and not so much fuel and when it fires off you can fry your pistons, blow a gasket if you're lucky, backfire (Thus also ignitiong the fuel in you're manifold = exlosion).

I mean imagine 950psi of liquid nitrous shoting in your engine at 2krpms and
Imagine it shoting in at 4krpms. At which rpm does the engien swallow more nitrous?
...And what happends when the engine doesn't want to move any faster? That's right a cyl. FULL
of nitrous and way too little fuel.

That's why you're not sapposed to spray in 5-4th gear in high loads and you
can get away spray off the line in 1st or 2nd.

You're going 110mph in 5 gear and start to slow down at 2k DO NOT HIT THE NITROUS Risky ****.
lol, what was I talking about and why did I post this? :/ (_)_):::::::::::::{}

 

http://videos.streetfire.net/video/F...DFFDB8FE6A.htm

 

stop playing around with the jets and get it tuned properly

 

Read post #21..thanks for boosting your post count. Have a nice day!

 

Wow... If the lawnmower can handel a 60 shot, maybe my VQ can...

Yet another project for this summer

 

Most of it was comeing out the carb though.

 

I was joking...

It's obvious that the VQ does quite well with a good nitrous setup.