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Discussion Starter #1
So is anybody running the bigger 8-10 jet spreads like say 40n/30f instead or 42/32 instead of 4 jet spread (40/36) ?
 

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Bostick Racing Engines
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So is anybody running the bigger 8-10 jet spreads like say 40n/30f instead or 42/32 instead of 4 jet spread (40/36) ?
Ran 28/20 w/7psi in my Crusader... like it.
 

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"BOATLESS"
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.?

In my plate NOS cheater system I ran a 90n 80f jet for a 250 shot, Not sure what the fogger is going to want with a 350 shot. That's with 6psi flowing, 7 static. Ran MANY bottles that way, 7degrees retard.
 

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"Need For Speed"
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Rick it is all about the Nitrous to Fuel Ratio. You can run a larger spread as long as you get your flow and pressures balanced. I actually think the bigger spreads are safer. For one example, let's say you have a 1 lb pressure drop on your fuel during the pass. A 1 lb pressure drop from an 8 to 10 lbs system is a lot less percentage drop compared to a lb from from a 4 lb system. Also the fuel atomization is increased with smaller jet higher presssure.
 

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Discussion Starter #7
Rick it is all about the Nitrous to Fuel Ratio. You can run a larger spread as long as you get your flow and pressures balanced. I actually think the bigger spreads are safer. For one example, let's say you have a 1 lb pressure drop on your fuel during the pass. A 1 lb pressure drop from an 8 to 10 lbs system is a lot less percentage drop compared to a lb from from a 4 lb system. Also the fuel atomization is increased with smaller jet higher presssure.
That's why all the questions. Was trying to understand why alot of folks were running such big spreads. All the people I've talked to running the big spreads say My 40/36 with 6.1 fuel is slobbering fat. A little fat I can see, but hell it's turning 1000-1100 rpms more with that tune. Trying to understand why some say with less fuel & more pressure it'll run even harder ?
 

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mo balls than $cents$
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Lean is mean;) when i built and tuned that engine alter ego has now i ran a 500hp shot in 2stages at 8psi(rock steady during flow testn over bucket). Had a set of shit shorty headers with a wideband and i kept leaning out the enrichment fuel till i had 12.0afr on 200hp and 11.7ish on both stages and never hurt anything.reading the leanest plug the whole time of course but it picked up another 200rpms leaning it out and as i said motor still lives tday after a ton of nitrous thru it. i jus lower fuel psi on the bypass regulator for lean out and smaller fuel jet on 1st stage.nitrous express wanted me at their ratio and 10psi.hell that had me in the low 11's and black plugs.was goin thru ngk 8's consistently.i like to read leanest plug and watch afr even tuning nitrous blowers turbo deals.nitrous companies do there ratios and psi at a pretty safe rich tuneup jus to keep customers from melting shit:) i leaned mine out and ran a 13 to 1 505 on avgas and enriched nitrous with 112 supreme lol plug reading and a 180 buck wideband kit wld be a big help if ya got some shit headers to use.


hey when u had the cp tunnel did u run a blocked loader or open?
 

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That's why all the questions. Was trying to understand why alot of folks were running such big spreads. All the people I've talked to running the big spreads say My 40/36 with 6.1 fuel is slobbering fat. A little fat I can see, but hell it's turning 1000-1100 rpms more with that tune. Trying to understand why some say with less fuel & more pressure it'll run even harder ?


I run a 36/24 with 5 1/4# of fuel pressure, pull out 12* timing and it's not lean, pick up 2700 RPMs on that tune up,
But if i was you i would listen to what Red Rocket says about it.
 

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Discussion Starter #11
Farmer John , I wanna make sure I'm understanding here, Your gaining 2700rpm from that tune up ? If so WOW !
 

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Farmer John , I wanna make sure I'm understanding here, Your gaining 2700rpm from that tune up ? If so WOW !
I know it sounds out there, but i'm running a hi-helix A in that boat and it dosen't even get up in its max horsepower range with that impeller (in fact it's a pig off the bottle) thats why its gaining 2700RPM on that tuneup, efficent no its not but it works for me, and the plus side at 5000RPM its running 102 MPH and you can cruise quite a while like that if you don't mind taking a little beating in a little 19 footer
 

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I know it sounds out there, but i'm running a hi-helix A in that boat and it dosen't even get up in its max horsepower range with that impeller (in fact it's a pig off the bottle) thats why its gaining 2700RPM on that tuneup, efficent no its not but it works for me, and the plus side at 5000RPM its running 102 MPH and you can cruise quite a while like that if you don't mind taking a little beating in a little 19 footer
You must have the same GPS as Tony:rolleyes:
 

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Id like to convert my Dual stage snowmobile nitrous over to my boat. No fuel pump. It uses NPFI. Nitrous Pressure Fuel Injection. Its a trick nitrous nozzle that pressurizes the fuel nozzle at the same time! No fuel pump fo fail, No Nitrous shut off selonoid to fail..wiring...etc. One 9v nimh battery runs the system and it operates on 300psi bottle pressure. So bottle Temp issues are totally avoided etc. On my 180HP NA snowmobile I use Methanol as a supplement fuel with N20. 60hp on the first stage with 30hp on top of that. 270HP total.. Pulling 15 second runs UP steep hill climbs with great success at full timing. Someone needs to convert one of these systems to a boat. Might not be the biggest system created but sure a nice way to have some reliable fun! A cheater system would be a piece of cake. I would try it right now, but my boat is EFI.
 
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