Originally Posted by F-BIRD'88
I don't recomend T ing off the nitrous from a mechanical fuel pump.
Mechanical fuel pumps are great and can flow enough fuel of themselves but are effected by heat. Heat on the feed side fuel line. Exhaust, eninge block ehat etc.
These pumps will not move air bubbles thru the line. When the fuel in the feed side line from tank to pump gets hot the fuel boils. Becuase this is the suck side (lower pressure) the fuel boils in the line even easier.
When the ful pump stops moveing fuel to the carb or nitrous, ya burn up the motor. Lean vapour lock.
If you want to get into nitrous you want an electric fuel pump and a separate dedicated fuel system with electric pump for the nitrous.
You must have a bullet proof fuel delivery system. Nitrous only damages motors when you make a mistake. using a mechanical fuel pump with a T for the nitrous would be your first mistake. First time the feed side fuel line and/or the body of the pump itself gets a little too hot, good bye engine.
This combo is well capable of 10sec Quarter mile ets on 150hp used right at launch thru the whole quarter mile. Do not use a low stall converter. "3000 stall" minimum (11" converter) A 10" 3500 stall is not too much. A low stall torque converter on nitrous just adds to the potential of engine damage (overstress connecting rods) That would be your second mistake. You will need a drive shaft safety loop, slicks or ET streets and rear airlift airbags for traction. Do not use anythng but the best available fuel on nitrous.
Low octane gas would be your third mistake. 92-94 octane is ok with 150 hp.
Do not be afraid to add (unleaded) racing gas even at the 150hp level.
If you want to run more shot use 110 octane racing gas.
Race gas is cheaper than engine rebuilds.
l've found the holley blue pump to be unreliable in every day steet use.
They always start to leak or quit on ya. If you ever take on apart you'd see why Lucky if you get a year out of one.
These pumps pump a lot of fuel but do not last. They were never designed for daily street use. They are fine for a drag car. (until they start leaking)
On my car I use two two separate 3/8" fuel lines with in tank pickups, two 3/8" in line paper elemement fuel filters and two Carter P4594 fuel pumps. 7psi. No regulator is required for the carb. A holley regulator is used on the nitrous side. Its simple, One for the engine , one for the nitrous system.
Its bullet proof, its affordable and easy to install and to get replacement parts. (common 3/8" fuel line stuff) The combined system is capable of supporting a combined 900hp. It works. When you properly rubber mount the fuel pumps on a proper mounting bracket they are quiet. The engine/exhaust will be much louder. For normal street driving and for N/A drag runs you only switch on the engine system.
This is one good way to do it.
Thanks for the info. I didn't think it was a good idea but thought I would pose the question as I'm sure someone else has wondered. I've played with nitrous for awhile so I'm familiar with the setup/usage and making sure everything is right (timing, plugs, fuel, etc). I don't plan on using the nitrous on the street but I have access to 110 octane airplane fuel which I used to run in my 87'. Only difference is it has some antifreeze in it but on a carb'd application with no O2 sensor it worked great. I ran a seperate Holley blue for just my nitrous on my 87', didn't use it all that often so never had any leakage problems. I might end up just putting a sump in the rear and running the lines off of it. dual 3/8's like your setup. It's still awhile down the road so I have plenty of time to put the pieces together. My last nitrous motor was in my 98' GMC
Was running a 150 through it and a 100 + 7psi from a blower for awhile. That truck is STILL running strong today with well over 180K on the short block, and man did it move lol. My 87' was a solid Lunati cam, Vic JR, Dart II heads, 360ci, Holley 830cfm, non-lockup 700R-4 with 4000rpm stall, 4.10's with BFG Drag Radials. Now that car hauled the mail(11.90's on motor at 119, was setup for a 250 but never used it at the track).