Nitrous jet ?

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Nitrous jet ?

Post  57ford custom on Mon 21 Aug - 15:25

I am putting together my 460 after a (non nitrous) valve guide problem and am planning on finally trying my NOS system out. I have 2 edelbrock 750's on my engine with my old NOS cheater plates on this Weiand tunnel ram flat tappet engine. I would like to know what jet sizes for a 50/75/100 hit on each plate. The last time I used the kit was many years ago when I understand that the jet sizing was a bit different than it is now. I will be using a mixture of 110 and C14 fuel and plan to retard at least 2 degree's per 50 hp. I used to spray my Yblock with these plates and it worked good. I do have a separate fuel system that I used to set at around 7 pounds. This is a low 7 second 1/8 mile car without juice.
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Re: Nitrous jet ?

Post  supervel45 on Tue 22 Aug - 1:27

57ford custom wrote:I am putting together my 460 after a (non nitrous) valve guide problem and am planning on finally trying my NOS system out. I have 2 edelbrock 750's on my engine with my old NOS cheater plates on this Weiand tunnel ram flat tappet engine. I would like to know what jet sizes for a 50/75/100 hit on each plate. The last time I used the kit was many years ago when I understand that the jet sizing was a bit different than it is now. I will be using a mixture of 110 and C14 fuel and plan to retard at least 2 degree's per 50 hp. I used to spray my Yblock with these plates and it worked good. I do have a separate fuel system that I used to set at around 7 pounds. This is a low 7 second 1/8 mile car without juice.

Yes they changed the NOS charts several times from the old days.
My 73 Nitrous Jet went from being a 150HP on a Cheater plate 175HP on a Big Shot plate to a 180HP on the newer charts or more for I believe with the Cheater Plate. Fuel jets have also come way down from what they used to list which was an 82F 73N for the above combination.. I am still pretty Old School and would rather risk washing my rings as they claim now then to leaning out after seeing the immediate damage or one pass damage that it causes. I would start with your 50 shot on a dual quad or a ram just to make sure everything is working right on an old system just to be safe. I have also found on lower compression engines between 8 to 9 compression that you don't have to pull much if any timing out until over 125HP if then even without race fuel likely because the tunes were overly fat. I pulled none on the 73N pill on my 429 and I saw no signs of detonation on the piston tops or rings or lands when I pulled it down for other reasons and had many bottles through it over the years. Again better safe then sorry. You can also tune it some with by lowering the fuel pressure regulator but the old rule was to make sure it always has over 3 1/2lbs or more at flow at least I believe that is where the old NOS fuel pressure switch's cut out. If you keep 5-7 and tune with fuel jets it should give you more safety margin with fuel delivery issues if problems arrive in theory and I always liked 5-6Lbs.. If you go for the 200 deal on say a 11-12 comp. engine or in that range it getting time to think about dropping spark plug heat range. Keep in mind this is my experience and a lot has changed. One thing I have noticed is a lot of these new hard corp nitrous guys are running their engines right on the edge of blowing up every pass and there are a lot of Hairy Tunes and Wild advice (My Opinion) floating around out there now.

PS: On my old 292 Y-Block I ran the old 125HP jets in a cheater plate at the regular N/A timing on pump gas. Never missed a lick and shocked quite a few people for what it was. Cool

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Re: Nitrous jet ?

Post  57ford custom on Fri 25 Aug - 23:46

So what do you recomend for my jets on this setup 50/75/100 per plate
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