Just finishing up plumbing the nitrous setup on my car and I need some help with sizing the jets. I called NOS to get the info from them. But the tech guy didnt seam to care and without me giving him all the info he said I wanted to run .026 fuel and nitrous jets. I dont really want to go off of just what he said. So below I will list my setup and let me know what you guys think.
Fuel and Nitrous jet size for 200shot 5.7L LS1
Direct Port Nitrous Setup
(2) NOS "N20 Super Pro Shot" Solenoids
NO. 16045
(2) NOS "Fuel Cheater" Solenoids
NO. 16050
(8) NOS Foggers
The setup has 2 nitrous solenoids and 2 fuel solenoids.
__________________ 06 Trailblazer SS
93 Supra Turbo
93 RX7 LS1
Location: In the garage, working towards a 2900 lb raceweight :D
Posts: 10,797
How much power do you want to run, and what do you want to use for fuel pressure? Cam spec's, bottle pressure, tranny, converter, gear, car weight, tuning ability, etc.etc. are all needed to really get a better idea of what you're trying to do and with what parts.
You running a low pressure fuel system? Run away screaming from NOS jetting, I can't believe they still tell people to square up foggers like that. I would run a 4 jet spread (26N/22F) and start out around 5.5psi for fuel pressure and 900psi bottle pressure. That should get you fairly close, then adjust fuel pressure from there based what the plugs say. I ended up at 24N/20F with 5psi on my tune up. If you're running high pressure off the rails, nothing i said helps.......sorry.
Location: In the garage, working towards a 2900 lb raceweight :D
Posts: 10,797
Square tuneup might work on some engines, or if you have the car very lean off the jug, but generally speaking it is too much fuel, way too much (unless you're off the map on your fuel pressure, like down to 4.5 lbs or something that low) A pump gas setup might need a square tuneup... but generally speaking, it's a no no.
If you're on a high pressure fuel setup, it's a totally different deal, probably a 10+ jet spread, depending on the fuel pressure. And, the danger in this, is that the fuel jet gets so small it's really easy to clog one, which is a bad situation
How much power do you want to run, and what do you want to use for fuel pressure? Cam spec's, bottle pressure, tranny, converter, gear, car weight, tuning ability, etc.etc. are all needed to really get a better idea of what you're trying to do and with what parts.
Motor should put down 400-415rwhp.
I am looking to spray a 200rwhp shot.
Cam FMS F5 224"/228" .588"/.576" 112LSA.
Bottle pressure last fill was 950psi (should I run a different bottle pressure)
I am running off of 2 Walbro 255 intake pumps with a 8an feed to the rails. Fuel pressure with be in the 55-58psi range.
Car has a T-56 and a LS7 clutch for now. Plan for a Spec later on.
Car weight is 2740lbs.
Rear end is stock IRS w/4.10's
Car will be tuned by SlowHawk for the spray once it is complete.
__________________ 06 Trailblazer SS
93 Supra Turbo
93 RX7 LS1
Square tuneup might work on some engines, or if you have the car very lean off the jug, but generally speaking it is too much fuel, way too much (unless you're off the map on your fuel pressure, like down to 4.5 lbs or something that low) A pump gas setup might need a square tuneup... but generally speaking, it's a no no.
If you're on a high pressure fuel setup, it's a totally different deal, probably a 10+ jet spread, depending on the fuel pressure. And, the danger in this, is that the fuel jet gets so small it's really easy to clog one, which is a bad situation
Ya I am a high pressure setup for now. Down the road I will upgrade to a stand alone low pressure setup.
Quote:
Originally Posted by jmm98LS1
You running a low pressure fuel system? Run away screaming from NOS jetting, I can't believe they still tell people to square up foggers like that. I would run a 4 jet spread (26N/22F) and start out around 5.5psi for fuel pressure and 900psi bottle pressure. That should get you fairly close, then adjust fuel pressure from there based what the plugs say. I ended up at 24N/20F with 5psi on my tune up. If you're running high pressure off the rails, nothing i said helps.......sorry.
Thanks for the info, but yes I am a high pressure fuel setup.
__________________ 06 Trailblazer SS
93 Supra Turbo
93 RX7 LS1
Location: In the garage, working towards a 2900 lb raceweight :D
Posts: 10,797
I'd start at 55 psi and around a 16, adjust teh fuel pressure ( I assume you can with an adjustable regulator) to get the tune right on the jug, then if the n/a needs adjusting you can add or remove fuel via the tune.
high pressure, is going to he a pita with a DP due to the jet size though, you're going to have to literally pull every fuel jet and clean them before every track trip to make sure they are clean (soak in some alcohol or carb clean or the like, and make sure they all go back in the same place, or just spend the extra $ and get a matched set so it's not a concern)
I'd really reccommend getting a standalone, or build one yourself. Pretty cheap to do if you build it yourself, cheap holley regulator, holley blue pump, 1 gallon cell, and just run the lines as needed. I'd really do that and set it up with a 4 jet spread and about 6.25 lbs of fuel pressure (verified with a flow guage) to start, and adjust the fuel pressure to get the tuneup right.
What size jets for my direct port setup? 
