Nitrous Oxide plumbing
Turbo Mini Forums

Sorry if this is a heretical subject.I know a few of you have fitted NOS systems,and I've been running mine for about 2 years with no problem,albeit at only 25bhp.My question is,do you plumb the fuel feed from the line before or after the regulator?Mine is before the reg so the jet sees full fuel pressure(and is only activated on full throttle),but it has been suggested that I should use the regulated fuel flow.Since the NOS injector is before the plenum,this would mean that fuel pressure would roughly equal boost pressure=no flow?
Any advice would be much appreciated.

'Where does the engine go?'

hi steve ,
the fuel pressure is normally 3 to 4 psi ,above the plenum pressure ,so that is what it would be in this case if you take the fuel from after the reg .

also , if the reg keeps fuel pressure at 4 psi ,then the rest is bled off back to the tank ,then the line into the reg from the pump may be very near 4 psi too ,unless the pump is huge and the reg return small . i suppose in that instance ,there is a chance of the line pressure, from the pump ,actually dropping as the bhp from the engine rises ,and the n2o running leaner .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

always take the fuel from the highest constant pressure source, you do not want any variations in the fuel pressure when using gas for the reason Robert states,

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Thanks guys,of course you are both right.Thinking of the whole fuel line as a pressurized tank (ignoring line losses for a moment) then there are 2 outlets - float chamber and return to tank,with the reg maintaining pressure in the whole thing at boost+4psi.So from that it doesn't matter where the NOS fuel feed is.However line losses mean the pressure will be a little lower at the carb end of the line.Balanced against that,the line loss in a long thin NOS fuel line may be greater,so a carb end take off may be best.......?

Edited by steve1275 on 6th Aug, 2012.

'Where does the engine go?'