Carburated WET system Questions
Thread Starter
Racer
Joined: Feb 2005
Posts: 387
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Carburated WET system Questions
I have a 383, with a 780 Holley vacuum secondary. gonna buy the racetronix 340M pump and wire kit. I have the mallory return style regulator, with the stock pump.
I'm buying a nitrous kit from my friend that was originally for a tbi camaro. I'm gonna buy a different spraybar and use it on my vette.
How should I plumb the fuel to the spraybar? from the outlet of the regulator, or before, @ 60 PSI?
I'm buying a nitrous kit from my friend that was originally for a tbi camaro. I'm gonna buy a different spraybar and use it on my vette.
How should I plumb the fuel to the spraybar? from the outlet of the regulator, or before, @ 60 PSI?
Supporting Vendor
Joined: Oct 2004
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4BBLC4 - The relief style regulator you are going to use maintains a steady rail pressure by "pissing" back all unused fuel. At idle it's a lot of fuel at low to no pressure - at WOT it could be almost no fuel depending on the carb's useage, i.e., you must connect the spray bar to the high side (in this case same as carb). However, TBI systems ran at 12 to 24 psi so you may not add as much fuel as needed. You may need 3 regulators: first one set for say 35 psi with it's own return. Off this new MAIN rail two more regulators one for the carb and one for the nitrous. These two regulators could be PRV style (hold back's with no return) or two more relief style with their returns plumbed to the MAIN return.
Thread Starter
Racer
Joined: Feb 2005
Posts: 387
Likes: 1
What if I just Y'd the output of the regulator I have, and hooked it up to the nitrous and the carb?
But I would think it would still be better if I hooked up the nitrous plate to the fuel on the "high" pressure side (60psi) before the regulator, then the regulator would just supply the carb, and and return.
I don't really see how 3 regulators would help... why not just y off of the regulator? Or are you saying the spray bar need more psi than the carb (carb runs @ like 4-6 psi)
If that's true, why not use 2 regulators - the return style with a y on it, set to like 24 psi - and a non return right before the carb set to like 5.
But I would think it would still be better if I hooked up the nitrous plate to the fuel on the "high" pressure side (60psi) before the regulator, then the regulator would just supply the carb, and and return.
I don't really see how 3 regulators would help... why not just y off of the regulator? Or are you saying the spray bar need more psi than the carb (carb runs @ like 4-6 psi)
If that's true, why not use 2 regulators - the return style with a y on it, set to like 24 psi - and a non return right before the carb set to like 5.
Supporting Vendor
Joined: Oct 2004
Posts: 761
Likes: 68
4BBLC4 - You could do what you said last, however you lose the advantage of the return style regulator on the carb. I do not think you understand the workings of a relief style regulator versus a PRV style regulator. The relief style regulator can be indexed to manifold pressure resulting in a lower carb fuel pressure at idle (desireable) with an increasing fuel pressure at WOT (also desireable). A PRV regulator feeding the carb will result in high fuel pressure at idle (undesireable) and lower fuel pressure at WOT (also undesireable). Relief style regulators can be made to track the load. PRV's can also be indexed to engine vacuum but still cannot track load as well because they are a supply side regulator where as the relief style regulator being on the return side is load sensitive. Fax me a sketch of what you think you want to do (201-891-9295) and I'll check it out. 20 years ago I ran high pressure fuel pumps on carbs (with and w/o blowers) with relief style regulators. I still have sketches of all kinds of set-ups. Include a fax return number. Regards Greg
Last edited by BlowerWorks; Mar 5, 2005 at 09:36 PM.
