Think of spraying a garden hose into an empty medium-sized bucket, over to one side. The water will go into the bucket and spray back at you. If you move back from the bucket, then maybe the bucket will fill quicker - especially if you point the hose at the center of the bucket. Since I found this relationship today, I've searched for more links to "nitrous" "direct port" and "reversion" and found a lot of descriptions of similar problems. The real nitrous pros know all about it - and this is what I've been missing for the last few months.

Of course it's more complicated, but it makes sense. I'm going to move all six nozzles back on the manifold runners as far as possible and see what happens then. With any luck.... I don't have anything to lose here, so I'm going to work on this issue.

 

One of the more advanced forum postings I've found discussing nitorus reversion..... It's kinda long and crude in places, but discusses nitrous reversion pretty well. Now I just need to decide where to re-locate my six nozzles....


http://www.norcal1320.com/forums/arc...95704-p-2.html

 

I got this surge tank from Kgkeen101 - probably won't install it until early spring, cause it gets cold in the winter.... 10* F today. Brrrr....

 

Good read! Love learning new information regarding nitrous.
Nice tank!

 

I hated to see his car parted out, but.... I got the tank anyway. Now if I can just figure out how to cope with the nitrous reversion problem I seem to have created for myself.

What have you been doing lately???

 

Good stuff harold ... i've been swamped with work ... but made a little something something on the side hehehe lol

 

OK - what's the story ??? I've been wondering about you and that monster "whale"... I hope you've been having more fun than me. come on -spill it !

EDIT: Never mind - I just found your All Motor thread. Dang- that looks good. In for the dyno....

 

Back in california for the holidays.

I will start racing my car again once the weather warms up in kansas. Kinda having problems with the tranny but screw it I wanna race.

 

California - sigh..... Racing - yeah ! (in about four months. maybe) For now, this is the land of Brrrrrr.....

 

Yeah not really looking forward to this winter. It's pretty damn nice weather in california right now!

 

I read that California - where drag racing really took off after it was invented in Kansas - no longer has any open strips. Is that true ???

 

We have one 1/8 mile track and one 1/4 mile track still. It sucks. So many tracks get closed because of noise

 

Yup, airports have the same problem. "Build it and they will come" even if the new airport is 25 miles from anywhere. Denver's new airport, way NE of Denver, is experiencing massive construction around it. People build new homes near an airport (read: drag strip), then ***** about the noise until it has to close and build somewhere else.

 

That's exactly the problem. They know they are building by a high decibel noise area and they think they can handle it. Give it a couple years and then they get mad. Happens every time.

 

Dang "civilians" - they want a quiet neighborhood to raise their kids then move into a high-noise area and complain about their own stupid decision.

I think I have a possible solution for my nitrous reversion problem, where the nozzles blow the injectors output back out of the cylinder. I've been digging into the pro racers forums and have looked at many spray patterns made by spray bars and plates, then found a photo of custom nitrous nozzles made from curved tubing that sprays into a runner just at the junction of plenum and runner. I made some clearance measurements today using Play-dough and searched eBay for parts and tools and think I have located what I need. It's too complicated to explain and won't be easy to build everything, but I think it will be an elegant solution. More to follow.

 

Here's a real photo from Induction Solutions showing how to extend nozzles into a runner from the plenum:

Notice at the top of the manifold where there is a separate feed line for fuel and nitrous, with lines branching off for each intake runner and merging into a nozzle as the lines enter the runner. I think I can do something similar on my '08 Altima plastic UIM by 1) removing the plenum divider. 2) mounting nitrous/fuel jet mounts into the top of a 3/4" x 3/4" x 10" aluminum block and drilling out the bottom with matching nozzles and silver-soldering .180 OD/.080 ID copper tubing into each nozzle to create a pair of tubes for each of the six intake runners, then bending the pairs together and silver-soldering them with the tips together and extending just into each runner. Obviously more development is required, but this approach allows me to change the jets from the outside, on the top, and the entire assembly will unbolt and lift out of the manifold from the top when maintenance is required.

http://i240.photobucket.com/albums/f...nisherback.jpg

 

That is cool!

 

Yup - maybe - I just ordered some Numba-1 eBay parts for this bright idea.... Once I have parts-in-hard maybe I can think my way through the rest of it. I'll start with the top plate and work down through the layers.

Well, it's gonna be a long winter, so this project should keep me busy, right?

 

Hopefully not too long. I wanna race!
Atleast you got a cool project.

 

here is a option for you Harold

 

Damn that is awesome! Could hide the whole kit.

"Hey man you gotta be spraying it!"
"Nah, just on the motor, I'll show you."

 

I've seen that design before - I think for a Mitsibihi 3000GT. That wouldn't work with any large shot - that close to the intake port, "reversion" would be instant, and I've already got that problem. On the other hand, I've been working on another design. There will a 3/4" x 1" x 10" aluminum bar between each two 1/4" x 28 connectors (I don't have that bar stock yet) The nitrous and fuel feeds will be on the top of the plastic Altima UIM and there will be two pipes for each nozzle, nitrous and fuel, one pair for each runner. The nozzle will merge each .140" x .080" tube into a thin brass cover, with the nitrous tube ending about 1/16" before the fuel tube to atomize the fuel. Silver solder should hold everything together - that stuff's hard.

I don't think the UIM plenum will be too crowded, since I'm going to cut out the plenum divider anyway.

 

I had ordered some Dremel accessories - another EZ-Lock arbor, some Metal and Plastic cutting wheels for EZ-Lock, and a set of three sheetrock saws that look like drill bits. I used a plastic EZ-Lock blade to cut off the top of the '08 Altima UIM, and the sheetrock saw to remove the plenum divider. None of this work took very long - heck, it's a spare plastic manifold. Some vucuum cleaner work and hitting the ragged edges with a propane torch cleaned up most of the inside - no pix of that, I see.

Then I took another look on how I can mount 12 jet nozzles and assorted hardware and tubing, and came up with a simpler way to put it all together - at least, in my head.

Going topless:


Cutting out the plenum shelf:


Finished views:





New way to mount each nozzle - on a 1/4" aluminum shelf and the brass tube silver-soldered to the lower end of the nozzle - the tubing slides right into that part.






I think I can mount the nozzle pairs in-line with each intake runner so the plenum intrusion will be much less than I originally planned - even the nitrous/fuel tube pairs will be tightly coupled, I hope. I'll cut a slab of 1/4" 6061 for the top plate and drill a couple of holes to do a test-build for one runner. I still need a solid way to mount and seal the top plate, and some way to couple all nitrous feeds and all fuel feeds together into two solid hardline pipes, so that only one nitrous and one fuel hose from each solenoid is required.

 

I think these would work fine with the SSIM manifold - hopefully with better N2O distribution.

 

I've sprayed two nozzles through the TB and also two nozzles into the elbow, with a SSIM, and had constant problems with lean cylinders. Of course I was spraying a combined 175-shot in those two stages, so there were lot of chances to have problems.

 

Everything's looking good Harold! Hopefully this makes a good difference!

 

I went out to the hardware stores and came back - with a 7 1/4" saw blade that does a super job of cutting 1/4" aluminum plate. I marked out then cut out a piece to place over the opening in the Altima UIM, then located the vectors of the six intake runners, marked nozzle positions for one runner, then drilled and tapped the holes and screwed in two nozzles for a test fit.

The next step will be to silver-solder tubes into these two nozzles after countersinking a slope into one end of each tube so that this part sits under the nozzle jet. Then I'll be able to test bending the tubes to fit the intake runner.

I've also ordered a batch of .190"OD/.080"ID brass tubes to replace the usual 3/16" OD steel tubes so I can bring all six nitrous tubes and all six fuel tubes into two common manifolds and silver-solder them that way. With the shorter path and smaller ID of the supply tubing, response should be very rapid when the solenoids are triggered.

Pix attached, in no particular order:

 

I got the brass parts this week and today I built one prototype. The brass nozzles were drilled out to .140" on the downstream side, two short 6" brass tubes were cut and the end .080" hole on each tube was drilled out with a .140" bit, which creates a taper flow from the jet into the tube. The tubes were then silver-soldered into the bottom of a nozzle, then both threaded into the aluminum plate.

I then cut off each tube and bent them into position, cut them to end before the runner, cut a 3/8 piece of brass tubing and pushed it over the two tubes, the the fuel on top and extended over the nitrous tube. To keep the tubes from creating too much turbulence, I cut a piece of .010" brass sheet to fit within the two tubes and soldered the piece into the space between the tubes.

Since I haven't flow-tested the nozzle yet, I'll show all the pix I took today.

 

I had another thought about the brass sheet I put into the gap between the nitrous and fuel tubes. If the plenum is opened up - and it is - is it better to put the brass foil between all six spray nozzle pairs and hope that the filled gap will help direct air into the runners, or leave the gaps open and hope that the larger plenum will provide better airflow into each runner by drawing air from the entire plenum, including through the tube gaps?

 

Nice looking project. I would keep the metal use to a minimum, meaning leaving the tubes without that piece of metal in between. Only reason I say this is to reduce the probability of a freak accident of the weld loosening and being sucked in. I think the tubes are aerodynamic enough not to cause any problems.

 

Yeah, the thought of any of those metal pieces coming loose and being inhaled into the engine gives me chills - fast way to wreck a motor! But I'm pretty sure that won't happen with using the silver solder. The solder is hard when cooled and thick as well, so I don't expect things to come apart. The real reason for my concern is how the engine firing order 1-2-3-4-5-6 affects air flow in the UIM. Air is pulled into the runners starting on the passenger side and working across the runners and going Up-Down-Up-Down-Up-Down across the plenum and starting over. This is one reason that plenums get opened up - there is a larger interior space to pull air from - and that's what I did to this manifold. Hanging the tubing pairs out into the plenum can create some slight restrictions to air flow, but filling in the spaces with brass sheet will really block the air flow, and that's not good.

So I'm not going to do it at this stage of creating custom nitrous nozzles for the express reason of preventing nitrous reversion. Testing will tell me if this was a good idea - but this seems to be the only thing left to do. Obviously, placing the nitrous nozzles over the LIM ports didn't work out well. That setup just blew out the contents of the cylinder when the intake valves opened, which kept the engine too lean to be safe when spraying.

"it's always something"

 

I would think if going into the LIM it would have to be tapped at an angle to be optimum. I think the way you have it now should work with no problems. There should be enough suction from the cylinders at WOT.

 

I had tried two different sytles of nozzles mounted at the inlet of the LIM ports - one spraying at the forward edge of the LIM and one set at the center of the port. Both setups did the same thing - which is blow out the fuel sprayed by the fuel injector so that the cylinder filled only with what the nitrous/fuel nozzle was spraying.

Hopefully putting the homemade nozzles back further at the inlet of each UIM runner will allow the fuel injector charge to stay in the cylinder while filling the cylinder with the nozzle spray mixture. This should be interesting - because the plenum will be completely filled with the nitrous/E85 mixture. I have been planning a blowout panel for the UIM, although I think the thin plastic would blow out easily if there is an explosion in the UIM. That's exciting even with an aluminum UIM. At least the manifolds are pretty cheap.

 

Any new progress since your last post?

 

The cold weather/snow has kept me from any serious work, but I have gathered all the parts I need to make a final version of a nitrous spray-inator. Drill/tap sets, brass jet nozzles, machined and drawn brass tubing, 6061 aluminum plate, brass tubing and machined steel rod for splinting the drawn tubing, and misc hardware. Just words, no pix for now. Maybe this weekend, since the weather is warming up and my wife is going to San Francisco for an ACC conference !!

 

I hope the weather starts to warm up! That would be awesome! Time for racing

 

Wichita has an IFO at the end of March.... looks like the 24th.

 

Aww no way I'm gonna miss it! I'm going back home for spring break march 22-april 1. After that I will be doing a lot of racing!

 

Must be nice to get out to the track, even at the end of March. My local track doesn't start test & tune until the last weekend of April. Hell, season opener is scheduled for the second weekend in May (weather permitting) lol

Andy

 

This time of the year, there's no guarantee that the weather will be decent from one day to the next. You just hope for the best.


I'm still waiting on a couple of batches of parts to arrive, especially the 5mm Nutserts, but in the meantime I've built another 1/4" top plate for the manifold and drilled all the brass nitrous jet holders for the brass tubing and generally kept working on the nitrous spray system when the weather was decent - unheated garage, you see.

The further I got into making my own nitrous nozzles, the more uneasy I got about the idea. The most important thing about a nitrous nozzle is the abilty to atomize the fuel as well as possible, and be consistent with all nozzles used. If I make nozzles by hand, there is no guarantee that all will be consistent. Even if I'm spraying at each runner instead of blasting directly into the intake port like I'm doing now (which causes flow reversion and blows out the cylinder), I still can have rich or lean cylinders depending on the individual hand-built nozzle. This bothered me so much that I stopped, and came up with a better way.

Since I have a set of Induction Solutions 90* nozzles left over from the first attempt at direct-port spray, and some 1/2" x 3/4" aluminum bar, and some 1/8" aluminum plate, I had another idea. I can mount a section of 1/8" plate on top the UIM over the existing cutout, cut a piece of the 1/2" x 3/4" bar to fit on top, with the 3/4" side down, drill out six holes into the 1/2" side deep enough to take a IS nozzle, drill up through the 1/8" plate into the bar at the far end of each hole, tap the drilled holes for 1/16" NPT, and screw the IS nozzles into each hole and have six nozzles that will spray down into the open plenum while using the same jets. I mocked this up, and everything will fit. I'll place one nozzle over each manifold runner.

I can keep the existing 6-port nitrous and fuel distribution manifolds and just mount them on an aluminum plate mounted to the manifold and use the existing hoses as well. This will save a lot of work making new hoses. I just have to use longer -4AN hoses from the NX nitrous and fuel solenoids to the manifolds. That's the plan now. I should have six identical nozzles flooding the plenum with nitrous/fuel that will be pulled into each runner in the engine's firing order, and give be consistent mixtures in each cylinder. I feel better now.