I woke early thinking of your situation, I thought "what would i do?". Well i came up with this. Now mind you it is untested, I have used a similar scenario on cars before but not exactly like this. It would need to be wet flowed and at minimum a pressure gauge placed where you could see it under full load. Using it this way you wouldn't have to run a higher than recommend pressure, which in my opinion is defeating the purpose of running N20 to start with (another story). Anyway as i said UNTESTED, so it would be up to you to test this way. You will still have to run a return, But you should have everything else except maybe a triple y fitting, Which you may have to fabricate. On my return line i used the vapor line coming out of the tank, You will have to drill out the baffle under the cover. I would also use the same size return line as you use for supply if not bigger. Hope this will help. P.S. Its a crude drawing so no comments on my artistry?
I have been tossing a similar idea around, but without the return line. What is the purpose of the return line? I called Holley, and he saidthat my fuel pump will easily handle 500 hp worth of use at 6.5 or 7 psi. So, as long as the gas is getting into the intake, either via the nitrous nozzle or the carb, it is all going to get mixed up and burn. I have definitely been planning on putting at least a temporary pressure gauge where I can see that the pressure doesn't drop when I gun it.
The problem is not the pump, Its the regulator. Those 19.99 dollar regulators that they send with the pumps cant flow enough fuel Thur it (dead head). The orifice in the regulator that the fuel has to flow Thur is only 213 thous ants, The rod that unseats the ball is like 60 thousands. That leaves 153 thousands for fuel flow. But if you use the regulator as the way i have drawn out it makes no difference, The only thing will be if the orifice cant bypass enough then you will end up with high fuel pressure. Which ain't nearly as bad as no fuel flow. These little regulators has probably been responsible for more fuel problems than anything else. And also remember pressure showing on a gauge is a measurement of restriction, Not actual fuel flow.
OK, so i am already shopping for a better gauge, now I will need to look for a decent regulator. Maybe one that has both in one package? Project is on hold for now. If I have to re-plumb for the 3rd fuel line to the solenoid, then I want to do it right, and only once. So I have got to figure out how all this is going to go together and get my shopping list correct. I don't live near any speed shops, so I can' t just pop in and get one more fitting. Popping in to the speed shop, for me, is no less than a 3 hour trip.
that seems so wierd that holley doesnt include a regulator that can match the flow of the pumps. so if you use that regulator as a return style. you will have the carb and solinoid on the same side as the inlet side and then the outlet side will go back to the tank. i cant see that working sence the pressure controle of the regulator is done by the pressure difference on the outlet side of the regulator. the regulator does not care what the pressure is on the inlet side it. ive looked at alot of different brand regulators and find that most of them have what i would deem too small of an orfice to flow what i expect. but they have always seemed to work. im talking fuel injection and carb. with horse power levels up around 700 hp. i know that the valocity has to be very high at that point and also that the smallest point in the system is the restriction that will controle fuel folow and thus pressure.
Sorry guys. you are talking a step or two above my knowledge level, but I will pop in and listen, and hopefully learn.
Over the years dealing with Holley i have found they do a lot of things weird. I now try to buy anything but Holley if i can. After a 3000 dollar blower came apart in less than 100 miles and Holley said "OH WELL ITS A RACE PART" i quit dealing with them. As far as the regulator working from the outlet side, This is not correct. If you deadhead the regulator pressure will creep up till it reaches the pump by pass. If you plumb it the other way it is a continuous bleed so there is no pressure creep. If you want to prove that just put a gauge on and stop the flow, It will dead head and pressure will creep till it hits pump bypass. Now open the line and the pressure is constant to what it is set at. I at one time dead headed my nitrous system, When activated the Air fuel would go off the scale due to the high pressure that had built. After i bypassed it, it no longer goes rich when activated. But my main point in this, Is that the orifice may not be big enough for the nitrous and the carb. I dont know if it is or not. But if you take the regulator out of the equation then that one less thing that can go wrong.
I revised the drawing a little to maybe clear up some confusion. I had the gauge going to the wrong hole, Sorry.
i personaly run two seperat fuel systems on my car. one for the carb and one for the nitrous. the nitrous one is using a mallory regulator. its not a return style. i am not done with the system yet so i dont know how its going to perfrom. i have used this regulator in the past and never experienced any problems with it. i will keep a close eye on it for the creeping as that would be the only significat problem that i can see happening. i still have seen an answer or dont understand your answer as to how the holley non return style regulator can be used in return type system.
I to run a duel fuel system from the tank. My engine runs a BG mechanical pump (225 GPH). I use a Holley blue for the Nitrous with a Mallory boost referenced regulator (return style). You will have pressure creep problems, Maybe not at first but as the regulator wears it will start. I have never ran the Mallory dead head so i cant say for sure. The drawing is the best way i can explain as to how to plumb a non return style regulator. I have plumbed them this way for super charged motors with duel carbs. As i said i never did it on nitrous but i don't see why it wouldn't work the same as with the duel carbs.
mo has just got one of those regulators and will be doing pretty much the same thing as scooper. ill see about plumbing his that way and see if it works. when using the vent line for a return line, were going to have to modify the thing that goes into the tank and get a vented fuel cap?
I didn't mean using the line, you need a bigger line as the vent line is to small. some say they have used the line, But i would be afraid it wont pass enough fuel, My 3/8 is really to small, I cant go below 4 1/2 psi because it cant bypass enough.I meant I used the vent line out of the tank. Yes there is a baffle under the spigot that has to be drilled out. At least this is how mine was. I just drilled a small vent hole in my gas cap, Have had no venting problems as of yet.
ok thats good to know that the vent is to small. the line on my car is long gone so i didnt know what size it was. mo is looking at doing new hard lines so we will plan acordingly on the sizes.
wow . . . I'm with Scoop on this one, way above my head. Maybe you can explain it to me in person Bryant. I was thinking about stopping by tomorrow. Don't think I'll be mudding for a T5 anytime soon.
were all caught up right now. so if you can get there before the masses come flooding in we can get alot done.
