what does your afr do when you run it 3rd gear wot up to redline without nitrous?

Also, it looks like right before the video shut off your gauge read 10.2 which would be why excess fuel would pump into the exhaust then ignite. How do you see this fire?

I'm not real sure about with nitrous, but around 13:1 seems kind of high to me for wide open throttle.

Your afr slowly richens up as you are higher in rpms making me think that the nitrous pressure is dropping and causing more fuel than nitrous to be pumped into the car causing a rich condition.

 

That video IS an NA run, not a nitrous run, so to answer your question, thats what it does.

As for the 10 right as the video ends, thats after I let off. It does that while on the nitrous too, even moreso, I've seen it hit 9's. And, I know about the fireball because when I'm in a dark area, making just a short 2nd gear pass even, when I let off it lights up the entire countryside behind me, haha.

But yeah, sorry if that wasn't clear -- that video was an NA run, not a nitrous run. My bottle is a bit low from messing with it all day yesterday and taking a few friends for fun drives, so will have to get video of the nitrous run when I fill the bottle again, probably tuesday.

 

I pulled apart the fuel solenoid, and it looked good -- tested it, spraying into a bucket, and it seemed to have good flow. Not sure what else to even try now, lol. I suppose I could try moving the nozzle closer to the TB.

 

I missed this thread...



For N/A 13s are optimal. In your video it shows that it does lean out a little at the end (into 12s and then drop into 10s), but it's pretty good.

Also, the equal line length for solenoids to the fogger doesn't matter. With that short of a length to the fogger, the difference in pressures is negligible.


One thing about your set up that I think should be redone is the placement of the fogger. That's way too far from the cylinders for the nitrous mixture to travel, in my opinion. Although the nitrous gas and liquid fuel mixes into fine particles, the liquid parts are still there. So when you put the fogger that far away, you're increasing the chance of fuel ending up on intake tube wall, the butterfly, the bend at the top of the manifold, the manifold itself, etc.

Another problem I see with your set up is the fact that solenoids don't seem to be secured onto anything. You have to remember that those lines are under pressure and things under pressure within a flexible object have a tendency to straighten out.

 

I don't mean to nit pick, but you do mean it richens up, right? I haven't been using AFR's backwards for years, have I? lmao

Yeah, that is my concern as well. I picked that location based on other recommendations about enough distance for a good mixture -- many write-ups I've found recommend at least 12 inches between the TB and the fogger. But, Im wondering if the curvature of the pipe is affecting that. That is probably the next thing I'm going to change, and see how it affects it.

If that DOES fix it, then we definitely have some good info for the forum, lol.

The solenoids are mounted to a bracket that is bolted to the brake master cylinder's bolt. Its secure.

 

ok, so if that is NA then where is the log of hte nitrous?

You do know that when you don't have the nitrous armed and you do an NA pull that fuel solenoid will not open right?

The fuel solenoid only opens when the nitrous is armed at WOT when the nitrous solenoid opens. Therefore checking a/f ratio without the nitrous isn't the same as the a/f with the nitrous.

 

Of course I know that, my point was to ensure my NA AFR's were correct, and I didn't have a wack injector or something like that.

Will get vid (or better yet a real log) of the nitrous AFR in the next few days, gotta fill the bottle. Its actually all running great right now, my only problem is having to run a bigger fuel jet, and then extreme-rich on decel -- which all makes sense, if the nozzle is in a bad/too-far-away spot, I think.

 

oic, well the n/a looks fine. I wouldn't be too concerned about the n/a a/f since you can't adjust it without a piggyback or ems.

Get that bottle filled and log a 3rd gear WOT nitrous pull and we'll see what's up.

 

Word, I just wanted to eliminate it from the debug logic tree, hehe.

Will probably get that tomorrow night -- its been raining all week here, anyway :-/

Thanks for all the help, btw, guys

 

In bold above.
Why 3rd gear?

 

because wot in 3rd gear usually ends up in the 80mph range. 4th is too fast for most roads around us and will get a HUGE ticket verses a normal fine if caught.

2nd gear is too fast to get a good a/f log. I've tried logging it but it's so fast that there isn't as much data.


It just seems with my testing that 3rd gear is the ideal. Plenty of data but you're not breaking the sound barrier trying to get a log all the way to redline.

4th gear would be great if you could get it, i just don't like trying to worry about a logger and 100+ mph on public roads (even if they are deserted)

 

Ah, good point.

 

Okay, either:

1. My mysterious lean issues are gone all of a sudden

or 2. I got a bad bottle fill, or something similar.

Basically, I was able to go back down to the "proper" fuel jet today, AFR's were in the low-mid 12's.

Regarding the bad bottle fill -- can that happen? The bottle was half empty, and I went ahead and got it filled, since my bottle is mounted sideways, and I get really bad pressure drops during runs after a short while. When I purge, it seems real uneven -- could it have been filled improperly and a lot of air got in or anything? I dont really know much about how nitrous is filled.

Regarding having the bottle mounted sideways... any tips? I assume its best if I can just get the top higher, the bottom lower, and more towards the back as possible, lol. Otherwise, it seems I can reliably only use half a bottle. :-/

 

You can rotate the bottle so the nipple points forward and down at a 45º angle, because this points the tube inside the bottle toward the back.

 

Right, I have the label pointing at a 45 towards the front of the car, and supposedly the pick up tube is opposite the label. Maybe I'm going the wrong way though, I'll check the dynotune bottle instructions.

 

the valve has to be higher than the bottom. The siphon tube goes all the way to the bottom so the top needs to be lifted to keep liquid being pulled out.

If it's on it's side then you would be pulling gas and not liquid causing problems.

If your pressure keeps dropping you probably need a bottle warmer also to keep the pressure constant.

 

Right, yeah, the valve side is higher than the bottom, and I do have a bottle warmer, but the warmer can't keep up with the pressure drop after the bottle gets about half empty. When I got it filled, my filler told me that most people only get a half bottle out of a sideways-mount.

I may try to get the valve side even higher, or may just change the mounting position.

I do find it strange that my lean problems have gone away though.

Also, it seems to me that if mounting sideways, couldn't you take the tube out, and put the valve on the low side (if theres room) and get 100% nitrous for almost and entire bottle?

 

i'm not sure how that works with nitrous tanks. You would probably have to go to a manufacturer and have them build it that way. Tanks have to meet a pressure standard so it's not advised to just take the valve off.

i would just mount the valve higher.

 

Hey guys, again, thanks for all the help.

Just a quick update, I'm about 90% sure its the nozzle location that is causing the issues. Fuel collecting on the intake pipe is the only thing that would make it lean during nitrous runs, and rich when I let off. Gonna relocate it soon, and will let you guys know.

If that's the case, we'll be able to definitely say "Hey, don't put the nozzle back here"! Man, I love experimenting, haha.

 

You will probably get a little more power out of it as well by moving the nozzle closer to the TB. More of the liquid phase nitrous will make it to the CC. =)

Also, be glad that you didn't get a backfire. The first time I installed a n2o kit I developed a pool of fuel in the intake and blew up my throttle body... directly related to placement of the nozzle.