[71 Ventura II]

Yeah I'm dog paddling through all the info! On my "ICE" kit I had no jetting chart info to go on, in the beginning we tried jetting it using a chart I found on PontiacDudes website. At the time the kit was on my neighbors 377 SBC, if the bottle pressure was up it ran OK, but because it was way over RICH on the stagger when the bottle pressure dropped it would instantly fowl the plugs so badly the engine wouldn't idle. Even with the jets reversed (They have the fuel side larger than the nitrous which is bad) (The Edelbrock plate kits "square" jet same size jet both sides as an example) IMHO and only 600 lbs bottle pressure he dropped from a 12.52 to 11.69... 100 shot BUT....when we tried jetting it up to 150HP the bottle was down to low aka 500 lbs it ran like poop and barely made it back to the pits. PIG rich big time...

When I put the kit on my car we realized the NOS jetting stagger was retardedly rich! Too rich is BAD, not only for performance but for engine damage as well. I used the cold fusion calculator to get a baseline jetting and went with it. MY test @100 HP shot was jetted 46N 41F, fuel press 7lbs, bottle at +-900 lbs. IMHO it was a tad lean because when I checked the plug there wasn't a clear fuel ring at the base of the porceline. Remember both fuel and nitrous pressure can change the stagger.

I have my plate jetted 57N 52F right now in preperation for the final outing next Friday. It should give me +- 150HP shot.... I chose to go "1" jet up on the fuel side based on my previous test. I'm running the fuel pressure at 7lbs and total timing 30 degrees on Test #2 150HP. Shooting for 11.10-11.30's @+-119-121 mph. JD

[TIN TIGR]

learn this lesson well, and right now...a correct nitrous tune will not color your plugs..thats the gospel truth..if you see color after 1 pass, its still fat..i am sure it isnt too fat , where it should hurt parts, but you can go leaner..when people run away from you in the pits when you test the kit, it is about right...lmao..really

nitrous kits should sound like all hell is breaking loose under the hood..the more violent that engine accelerates, the better..

[71 Ventura II]

Note: Cold fusion says my Test #1 100 HP jetted 46N 41F was good for 96 FWHP which in my car would "Net" 74 RWHP. Since it dropped my car .65 in ET it wasn't too far off mathmatically from expected. With in say +- .10

[chiphead]

On plate systems, is it generally safe to start with "square" jetting at 5.5 PSI to start tuning?

Thanks!

[goatracer]

Originally Posted by TIN TIGR

learn this lesson well, and right now...a correct nitrous tune will not color your plugs..thats the gospel truth..if you see color after 1 pass, its still fat..i am sure it isnt too fat , where it should hurt parts, but you can go leaner..when people run away from you in the pits when you test the kit, it is about right...lmao..really

nitrous kits should sound like all hell is breaking loose under the hood..the more violent that engine accelerates, the better..

X2, I worked my tunes down to where there is almost no color at all spraying 400hp between both kits. Color on the plugs is unburned fuel in the chamber.

Bryan

[LiL Jack]

Originally Posted by chiphead

On plate systems, is it generally safe to start with "square" jetting at 5.5 PSI to start tuning?

Thanks!

It would probably be fat.


Maybe go with a 6-8 spread to start.

[71 Ventura II]

Originally Posted by chiphead

On plate systems, is it generally safe to start with "square" jetting at 5.5 PSI to start tuning?

Thanks!

imho square jetting is sooo rich it's to make the kit a "nitrous for dummies" thing! it's not for making the best power.

[chiphead]

Yeah, but if you look at the factory suggested jetting for Sniper, cheater and other kits, they start off with the fuel jet being 5-6 jets LARGER than the nitrous jet. I assume this is for when dummies try to use these kits with a factory diaphram pump. The jetting is right for 2-3 PSI fuel. I should be able to maintain 5-6 PSI. But all the online tuning sites I find say to start with the MFG recommendations...

I know I'm kinda asking the same newb question over again, but I'd have to buy $50-$75 worth of jets to be able to tune the 100 and 125 hits if I start way rich and jet down-down-down. Not to mention all the spark plugs I'm gonna foul. If you guys agree that I can start with square jetting, it'll help a lot.

According to the Cold Fusion calculator, going down .001-.002 in fuel jet size is the equivalent of dropping 1/4-1/2 PSI. When I make jet changes, can I go every other fuel jet size and go up or down 1/4 PSI to fine-tune? I.E. Go down 2 jet sizes and up 1/4 PSI? What's the strategy for sneaking up on the tune?

My bottle heater, purge kit and hobbs switches came yesterday. I'm scratching like an addict to put this thing together......

thanks!

[Engo]

Originally Posted by chiphead

Yeah, but if you look at the factory suggested jetting for Sniper, cheater and other kits, they start off with the fuel jet being 5-6 jets LARGER than the nitrous jet. I assume this is for when dummies try to use these kits with a factory diaphram pump. The jetting is right for 2-3 PSI fuel. I should be able to maintain 5-6 PSI. But all the online tuning sites I find say to start with the MFG recommendations...

I know I'm kinda asking the same newb question over again, but I'd have to buy $50-$75 worth of jets to be able to tune the 100 and 125 hits if I start way rich and jet down-down-down. Not to mention all the spark plugs I'm gonna foul. If you guys agree that I can start with square jetting, it'll help a lot.

According to the Cold Fusion calculator, going down .001-.002 in fuel jet size is the equivalent of dropping 1/4-1/2 PSI. When I make jet changes, can I go every other fuel jet size and go up or down 1/4 PSI to fine-tune? I.E. Go down 2 jet sizes and up 1/4 PSI? What's the strategy for sneaking up on the tune?

My bottle heater, purge kit and hobbs switches came yesterday. I'm scratching like an addict to put this thing together......

thanks!

You´ll be fine starting with squarejetting and 5psi of flowing presssure thru the same size n2o-jet as you have in the plate. Use brand new plugs. Pull out 6 degrees of timing and let it rip. Shut it off at the stripe and coast to return road. Pull at least a couple of plugs and have a look see. I bet they're gonna be pig rich.
Then be prepared to reduce fuel jet and/or increase n2o jet.
Before your plugs are clean (no fuel ring) you will probably end up with a ten jet spread at 5 psi of flowing pressure.
THEN, you can start putting some more timing in it. Go 1,5 degree at a time and watch the timing mark on the plug and your mph.
Good luck.

PS
That sniper system aint worth ****. Get a big shot system. They can be jetted anywhere from 50-350hp worth of spray and have quality parts.

[BrandX]

the sniper is less than average but will work for a small jet. A 62 jet wont get you 150 at the flywheel with that plate and noids.

[chiphead]

Is it the plate or the 'noids themselves that suck? The plate has 16 holes in each spraybar, supposedly the same as a super powershot plate. The sniper solenoids do look cheap and restrictive.

Is there any difference between a good purge solenoid and a regular nitrous solenoid? Does a purge solenoid have a tiny orifice? I just got a cold fusion purge solenoid, and it looks better than the Sniper's nitrous solenoid. Can I swap them around?

[71 Ventura II]

Until you get to a "Larger" nitrous shot the small noid can't be a restriction. As long as the orfice in the noid is larger than the jet It's a simple open/closed valve. Compare the orfice sizes between the two.

A good test to see if there is any difference would be to either flow each and compare or run both to verify. I'm voting they would run the same until you get above 150 HP. JD

[Engo]

Originally Posted by 71 Ventura II

Until you get to a "Larger" nitrous shot the small noid can't be a restriction. As long as the orfice in the noid is larger than the jet It's a simple open/closed valve. Compare the orfice sizes between the two.

A good test to see if there is any difference would be to either flow each and compare or run both to verify. I'm voting they would run the same until you get above 150 HP. JD

I´m sorry but that is not how things are. It is the total flow thru the system that counts. All parts affect flow and the noid is always a restriction to flow, just have a look into it and see for your self. Also remember nitrous is a liquid until it has passed the holes in the plate.

The "sniper" has restrictions to flow (compared to a cheater or big shot) in the bottle valve, nitrous line, solenoid and the plate itself. That and the fact that it is a low price system (you get what you pay for) makes it not so desirable IMHO.

[71 Ventura II]

Originally Posted by Engo

I´m sorry but that is not how things are. It is the total flow thru the system that counts. All parts affect flow and the noid is always a restriction to flow, just have a look into it and see for your self. Also remember nitrous is a liquid until it has passed the holes in the plate.

The "sniper" has restrictions to flow (compared to a cheater or big shot) in the bottle valve, nitrous line, solenoid and the plate itself. That and the fact that it is a low price system (you get what you pay for) makes it not so desirable IMHO.

Exactly, thank you for supporting the physics I pointed out. All you did was expand on every portion of the "system" to help identify other "potential" flow restrictions. The focal point of this inquiry was comparing to noids.

Narrowing the focus to the orfice size of each noid in question is the goal. Lets say the average nitrous system uses say a -4 feedline from the bottle to the nitrous noid. How large is the inside diameter of the line? +-??? I'm guessing 3/16" or slightly larger or .1875 or bigger.(Not yet the restriction) The orfice size on noids vary greatly depending on manufacturr but a good beginning is +- .076 up to .250. Point is, if you have a .1875 feeding even a tiny .076 noid,(Still larger than a .062 jet not a restriction yet) coming out through more .1875 to the nitrous jet say .057 to .062 it becomes clear. Restriction beyond normal frictional losses expedite at the jet.

Yes I agree there are big differences in bottle valve flow, different size lines between -4 & -6, plate design and max flow rate, and orfice size in the noids. I will conclude until the nitrous jet becomes equal to the orfice of the noid it's just not an issue.

Exept/Example: Now if there were calculations to support frictional losses when approaching say 80-90% ratio of orfice/jet relation it would be reasonable. If 80% was the max efficiency then the jet would be limited to .060 if you had a tiny .076 noid.

[Engo]

Originally Posted by 71 Ventura II

Narrowing the focus to the orfice size of each noid in question is the goal. Lets say the average nitrous system uses say a -4 feedline from the bottle to the nitrous noid. How large is the inside diameter of the line? +-??? I'm guessing 3/16" or slightly larger or .1875 or bigger.(Not yet the restriction) The orfice size on noids vary greatly depending on manufacturr but a good beginning is +- .076 up to .250. Point is, if you have a .1875 feeding even a tiny .076 noid,(Still larger than a .062 jet not a restriction yet) coming out through more .1875 to the nitrous jet say .057 to .062 it becomes clear. Restriction beyond normal frictional losses expedite at the jet.

You don´t seem to get it. Even if the solenoid orifice is bigger than the jet, it is still a restriction to flow. So your only valid point is the fact that the smallest passage will be the biggest restriction to flow, which in a well designed system would be the jet.

[71 Ventura II]

Originally Posted by Engo

You don´t seem to get it. Even if the solenoid orifice is bigger than the jet, it is still a restriction to flow. So your only valid point is the fact that the smallest passage will be the biggest restriction to flow, which in a well designed system would be the jet.

Simple physics, a beebee can't pass through the eye of a needle but it will roll through a garden hose. If one was to subjectively follow your reasoning it would be counterintuitive. Can you validate the forces at play to support your claim?

Lets associate the current scenario to another: Fuel system, "dead-head" and flow. It's a known fact a 1/2" fuel line will flow more volume than 3/8" line. Therefore we can conclude any fuel line larger than the 1/2" would flow even more volume. Physics tell us the larger the surface area of the opening also provides increasing pressure which is weird. But if you plumb a fuel system from cell to regulator using all 1/2" line, ending in a regulator restricting the flow to say 7.0 lbs, then where is the restriction in the system? The regulator...
If you installed a 3/8" fitting or adapter in your new fuel system then it would reduce overall flow of the system slightly. However the true restrictor is still the regulator not the slightly smaller fitting.

Something to research, look up various manufacturers of nitrous/fuel silinoids to collect advertised internal orfice sizes from each. Each company will give a HP rating MAX the noid is designed to handle. Granted the NOS website is not very clear on their stuff. Up until this point you have not offered any horse power limiting factors to your hypothesis only contending the Sniper noid is a restriction to performance. Clarify at what power level the noid in question is or becomes a restriction! I say even the Sniper baby noid will provide between 125-150 HP before any issue would arrise.

I have small diameter noids on my plate kit and have been told they can handle up to 175 HP shots but I think that would be a stretch. I have hopes of upgrading to the next size larger noids in the future; when I do I'll provide back to back results to help out. It still baffles me though, your saying if you ran a system jetted for 150 HP with the small noids first. Backed that run/runs up with runs after changing nothing but the noids to a larger orfice it would run faster? jd This would be a validation, perhaps I can put this to the test? Maybe next Spring....

[Engo]

[quote=71 Ventura II;4123972]It still baffles me though, your saying if you ran a system jetted for 150 HP with the small noids first. Backed that run/runs up with runs after changing nothing but the noids to a larger orfice it would run faster? [quote]

Yes, that is exactly how the theory goes. If you want to now more about it read a text book about flow physics. This is all about Bernouillis equation.
This explains why you never can say that a specific jet size will always give X amount of hp. (And I did not make that up)

In the real world.
If it will show up in a back to back test depends on how restrictive the smaller noid is and at what flow level (jetting) the system are set to.

Example. A NOS-cheater system has a fairly restrictive n2o solenoid. Jet the system to its max hp "factorysetting" and make a run. Then switch out only the n2o-noid to a Super Pro Shot solenoid (the one that comes with Big Shot system) and you will see a substantial increase in power added in the next run. I have made this simple test myself.

Now, if you jet the cheater-system to its lower hp levels the power increase from switching only the n2o-noid will be much lower and it may even be so small that it will not show up at a simple track test.

[chiphead]

Good physics debate, but 1 real-world test is equal to a thousand expert opinions.

So back to the original question.

At what HP level does the Sniper noid start to restrict HP?

Do purge noids have smaller orifices than a standard nitrous noid?

[TIN TIGR]

i can tell you the truth,but you would consider it an opinion..so why bother..engo speaks truth for the most part..some exceptions may occur..

when you quit asking questions about a sniper kit, you may address me..enjoy..

yeah, i am that egotistical today..

[71 Ventura II]

Originally Posted by chiphead

Good physics debate, but 1 real-world test is equal to a thousand expert opinions.

So back to the original question.

At what HP level does the Sniper noid start to restrict HP?

Do purge noids have smaller orifices than a standard nitrous noid?

I still vote between 125-150 HP. But I'm curious to see a back to back test at this power level. with the larger noid Run yours and see!!!

Also, go to yellowbullet or other website to see what they say. Good Luck! JD

P.S. I haven't found enough orfice information to comment on the purge/regular noid comparison.