I see alot of posts in this forum asking what jet sizes make xx amount of horsepower, so I thought I'd enlighten everyone with this list, provided to me by Nitrous Works (A division of Barry Grant). Enjoy......
Horsepower----------N20---------Fuel @ 38 psi -------Fuel @ 50 psi
25.................24.................18...................16
50.................33.................25...................22
75.................42.................28...................26
100................55.................31...................29
Of course this is a rough guide more than anything, since most nitrous kit manufacturers like to jet a little rich to be on the safe side. This chart should get you close with a bottle pressure somewhere between 900 and 1200 psi. I have a bottle heater and have been spraying the 75 HP shot for awhile now with the jets listed for the 50 psi fuel pressure setting. I try to keep my bottle pressure at 1100 psi or so. I've gone through about 30 lbs of nitrous like this and I still seem to be running a bit rich, but I will put it on the dyno soon to make sure before I change jet sizes or experiment with bottle pressure. I would suggest using an air/fuel gauge at the very least if you're using nitrous, so you can tune your setup. Just relying on the suppliers recommendations may leave you with an overly rich mixture that not only kills power, but can "wash" the cylinder walls down, causing premature ring wear and the resulting blow-by. A wash down situation happens because the unburned fuel acts as a solvent and washes the oil film off the cylinder walls, leaving them unprotected. Then you'll start burning oil, and basically turn your car into a POS. So the moral of the story is: here's the info, use it and be smart. Basic preparation and precaution taken early on can avert serious problems later. <br>
<img src=http://registry.gmenthusiast.com/images/jbeier/Jbeier_sig1.JPG>
According to ZEX:
kit #82021 (wet universal EFI kit)
HP - N2O - Fuel - Retard
55 - 32 - 17 - 0 degrees
65 - 36 - 19 - 2 degrees
75 - 40 - 21 - 4 degrees
I guesstimated on 85 hp as 44 N2O and 23 fuel. Seems pretty linear formula to me...
But those numbers are pretty different from the ones you've got... pretty lean, actually. Hmmm....?
I suggest the following:
Cold plugs
MSD
Good fuel
Balanced injectors
...j <br>
<br><br><a href="http://www.j-body.org/members/jlenko/cars/1/"><img src="http://members.shaw.ca/johnz24/images/nov30sig.jpg"></a>
I have the colder plugs, and I use Sunoco 94 when I spray. My plugs are telling me I was running rich, maybe because when I was running at the track I didn't have the balls to run any more than 1000 psi. I've since run 1200 psi and it's much closer to stoich, and a hell of alot more power. I'll get msd once I can afford it, but for now, I'm playing Rick King style. BTW, John, are those numbers for the 50 psi jets? <br>
<img src=http://registry.gmenthusiast.com/images/jbeier/Jbeier_sig1.JPG>
how do you retard a 99 sunfire GT. it is distributorless. my brother is running a 75 shot on stock eternals. i figure he will either learn by me helping him, or blowing his engine.
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what is the closest to the stock Fuel pressure? anyone happen to know exactly what the psi would be for an ecotec?
just doin some research before i jump into something
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It's supposed to be somewhere around 50 psi at WOT, but it's always best to check it to make sure your FPR is working properly. <br>
<img src=http://registry.gmenthusiast.com/images/jbeier/Jbeier_sig1.JPG>
Shot N2o Jet Fuel Jet Fuel Pressure
35------31----------18-----------47
50------35----------20-----------47
75------41----------24-----------47
100-----52-----------28-----------47
That is what I got from NX . . . .
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Not sure on the fuel pressures but heres N.O.S ratings. And WOW they run there stuff rich. Messed up BIG TIME on ordering my jets for what I thought was a 80 shot. Me and the guy at the shop read the chart for the wrong kit. So I have a .32 nitrous and a .22 fuel. So a REALLY rich 30 shot OOPS LOL
Shot Nitrous Fuel
30 .33 .18
50 .37 .22
70 .41 .26
80 .43 .28 <br>
Good Jesus, NOS is running RICH as HELL thats almost like a 10;1 air fuel?
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I find it quite strange that the jet numbers for different kits are that different from each other. Mine seems to be on the rich side if anything. I need to visit the dyno and wideband O2 to see what is what. <br>
<img src=http://ourworld.cs.com/jwithspray/Jbeier_sig2.JPG>
hmmm I see no info for a direct port there! <br>
91 GA 12.080@113.99 best 1/4 mile E.T.
www.killerquad4.com
jake@killerquad4.com
