Right now my N20 setup is "unusual" to say the least. The original setup was a compucar LT1 plate system, that looked at least 5-6 years old when I bought it used in 1999.

Since then, I changed to a single fogger setup (and am soon going to change to a shark nozzle), as I got sick of having to pay out the *** for compucar specific screw in jets at 15 bucks each (which are of ridiculously poor quality anyways).

As the bottom end of my fresh motor is built to handle well over a 200 HP nitrous shot, I tend to run anywhere from 150-250. The compucar N20 solenoid maxes out around a 175 shot, so I replaced it with a cheater solenoid, as I got a good deal on it, and was really quite over doing business with compucar.

Anyways, This weekend, my cheater solenoid stuck open, even though it only has had 2 bottles run through it, and I have always used a quality filter. I think I may be over doing business with NOS now as well. At least compucars solenoids didn't suck.

I went to a local speed shop, that cut me a simply awesome deal on one of the "BIG" NX solenoids.

So this gets to the question part. The shop owner was VERY apprehensive about selling me a different companies solenoid, as he said that even slightly different orifice sizes (like the difference between a cheater and an NX solenoid) could completely change the amount of flow.

I don't see why this would be a case, as the solenoids at the level we are talking about have much more than twice the orifice size of even the largest jetting I run. I think the AN-3 lines running to the nozzle are a larger restriction.

So anyways, I ran the ~175 shot, with .073 nitrous jetting and .040 fuel, and didn't see any different readings than the cheater solenoid.

I tune my N20 setup off of 02 readings and a visual plug inspection (shutting the engine off right at the top of 2nd gear, the coasting over and pulling plugs), and everything showed just fine, with O2 voltages hovering right around a very safe 1 volt.


However, the lack of a change could also be attributed to the fact that a single fogger is maxed out at what I am running. The internal orifice on a fogger is right in the .070-.075 range.

Thoughts?

 

a single fogger is maxed out about 125 horsepower.



adam

 

Nope. It doesn't have much more than that, but the orifice is definitely in the area of .070.

 

Depends on the orifice size of the nozzle.

 

As long as the solenoid orifice size isn’t close to your jet size, it won’t be an issue.

FWIW… I love those big NX ‘noids. Just make sure that you run relays with them, preferably NX relays. I’ve welded the terminals closed on normal 30A bosch relays with those (luckily, I was running a separate one on each ‘noid and the fuel one was the one that got stuck so nothing happened except the car wouldn’t run, couldn’t figure it out in a buisy intersection in DC rushhour traffic so I ended up getting towed home), turns out that the NX relays add a diode/cap to prevent internal arcing/welding (which I knew but didn’t think that the solenoids were going to be a problem)…

 

Yes, it is run off a relay, although it uses a single 30A.

I wasn't aware that much power ran through there. Your post leads me to think about upgrading.

I'm glad others came to the same conclusion that I did. Shop owner is probably just trying to save his *** from the eventual customer that comes back whining about how the nitrous part he sold them blew his motor...

 

Well, I finally melted mine with a progressive controller (I'm sure switching the things on and off repeatedly didn't help).

I'd guess they'd be OK. You can always measure across the resistance of both solinoids and compute what they will draw...

My GenX NX setup did come with 2 40A relays (if I remember right one was for the bottle warmer, but I ended up the 2 'noids on separate relays and they were happy after that)

 

I dont see how you tune off o2 readings during spray runs? My wide band says wtf when I spray my setup, and just about everyone else I know w/ a wbo2 does the same.

 

:shrug: thats why I pull plugs as well. The O2 sensor gives me enough feedback during a test run to know if I should be aborting the run.

 

That reminds me of 2 more things…
- one place that the jetting may become an issue: different N2O companies expect different bottle pressures. EX, last I checked NOS expects around 850psi, where NX was the first to religiously include/recommend bottle warmers and they jet expecting 950-1050psi.
- WBO2 readings are accurate, the sensor is not flipping out (though I would argue that it is probably a little on the slow side to really tune the initial hit by). Factory N2O jettings are setup for roughly 6:1 A/F ratio, to put you in a “way safe” range even if your fuel pump sucks (fairly likely with most users…). That way the dumbasses don’t stick them with the rep that “X N2O company blows up engines.”

 

I have run several "Frankenstein" nitrous systems over the years- different parts from different manufacturers. I found that as long as the solenoids can significantly outflow the jetting it doesn't matter who's solenoids you use. My expereince was on a fogger-injected big block (about 250HP total nitrous) and more recently on a simple plate system. Both cases the jetting produced the expected results even though the solenoids were from various manufacturers (but of adequate size). On the plate system I even ran a nitrous solenoid from one company and a fuel solenoid from another- it's what I had laying around. Worked just fine.