I nedd some advice. I have a stock 305 tbi fuel pump running my 357 carbed engine at 5 psi of fuel pressure. I am ussing a mallory three port afpr.

The question is will the stock pump handle a 125-150 shot on top of my engiine, which makes 350-400 horse. Also could I use one of the blocked ports on the regulator for the fuel feed to the Fuel solenoid.

Thanks, Josh

 

It is hard to say, I would first test it for pressure and volume and make sure it is up to factory specs. If in doubt rip it out, a new pump will not hurt.

Yes

 

Probabily not. It probabily won't maintain the minimum required fuel pressure while on the juice. On a Nitrous system's fuel side, the fuel pressure must remain constant all thru the run. It's just not worth piggybacking the nitrous into the engines fuel system when the pump you have is barely sufficiant to feed the motor at WOT max rpm.

For a NOS kit you want the pump to be able to maintain at least 6psi while flowing. You can fine tune the Nitrous/ fuel ratio from that starting point some down to about 5psi.
(usually you end up somewhere between 5 and 6psi)
Below 5psi things get too lean. (LEAN IS BAD)
A carter 4594 pump makes a good nitrous fuel pump fed thou its own 3/8" fuel line from the tank. Use a Holley blue regulator to fine tune the fuel pressure from 7PSI.

I like feeding the nos fuel from a small under hood mounted fuel cell and pump. Allows for a responsive short fuel system path, is gravity fed by G force , and allows you to fill the fuel cell with high octane racing gas at reasonable cost. (allows higher power of shot with complete safety and without exessive ignition retard)

Nitrous is a lot of fun and a cheap way to go faster but it's just not worth shortchanging the fuel side supply.

 

I agree with that. I shave a little more than 2 seconds off of my 1/4 times on the juice.

To give an idea on how much fuel pressure is lowered running the N2O, I am running 40-42psi normally on the spray pressure drops to about 24psi! This is with a Walbro 255 l/hr pump too.

 

So I should upgrade the pump then. I really dont want to run a complete fuel system for the n20 since it will barley be used.

 

Beats "barely" using the car, cause ya cheaped out and scattered the motor.

What is with this "I'll barely use the juice" s&^%!

If you cheap out on the fuel side and get it wrong, the damage will not be a little at a time, accumulating over time and use. IT WILL BE IMEDIATE . the first time. You won't get 600hp worth of fuel throu a stock fuel line reliabily.
Nitrous is injected into the motor at near 1000 psi. It hits the motor instantly. The extra fuel needs to hit the nos plate just as fast, or it will backfire or worse break a piston or bend a rod.

A dedicated fuel systen for the nos system will do that for ya.
A small compact fuel cell under the hood with a inexpensive extra pump (Carter electric) and short fuel lines is less work than installing a whole new 1/2" fuel line from the tank and huge $$$600hp pump or adding another 3/8" line and pump at the back. It will work much better. (reaction time)

You can do it without getting under the car. You can move the whole thing to another car if you want.
You can use the NOS when ever you want cause its done right and won't damage the motor. It only has to be 1 to 1.5 gallons.

Or you can do it with your head in the sand and always be afraid of the nitrous biteing your ***.

 

Okay so how do i wire up the second fuel pump to activate and how would I regulate the pressure, Another afpr I assume.

Also does anyone have pics of their install that would help a lot.

Taht Carter pump only has 1/4 feed, is that to small, what about a holley red or something.

 

If you are looking for a holley red I have on sitting in my garage. It is still in good shape, it has only seen 30 gallons of gas.

I am not sure if that will supply enough fuel, wait for one of the other guys to chime in. I have TPI and am unsure about the carb set up.

 

If it works out to be good how much would you like to get for it

 

Well looking at the newest summit they list at $95.88 I would take $75+ shipping.

 

The Carter 4594 has 3/8" NPT in and out. use 3/8" barb fittings or 3/8" NPT to #6an It's a misprint. Its not too small.
It's less $$ than a holley and will last a lot longer.

Use a holley #12-803 regulator and a fuel pressure guage
You have to set the fuel pressure while the system is flowing throu the plate (with the approprate fuel jet) or throu an equivelent oriface. (into a bucket)
Start at 6psi flowing for a NOS system.

if/ when you change the hp level ( change nos jets) you have to reflow it to adjust the fuel pressure with the new fuel jet. You can buy or make your own "flow tool".
It's best to wire the solenoids thru a relay.
Buy a inline nitrous filter. Some of the kits do not include one.

 

Wow, those Carter pumps are alot cheaper.

If you use the Carter pump I have the Holley regulator too. It adj. from 4.5-9psi.
I had a V8 S-10 project many moons ago and have all this stuff sitting, I have no use for it anymore. I have been selling it all off slowly but surely.

 

That afpr does not have a gauge port so where should I put it. I think some one has a piese that goes inbetween two hoses and has a 1/8 npt port so you can hook up the gauge.

and do you have any pics of your set-up.

They would help explain a lot.

 

The holley regulator has two outlets. You can use one for a "guage port".

Don't have any pics.

 

I was reading on NX website and they recomended if you use a seperate fuel system you should have a return. I assume this is to allow the extra fuel not needed to return to the fuel cell so you don't burn the pump up.

For a fuel cell would the RCI 1 gallon tank be enough. RCI-2010A

I noticed it had huge -8 inlet and outlet. Could I just use a fitting to go from -8 to 3/8 npt then run a line or better off screw the fuel pump right onto that connector, might need one more weather it is a male or female I can figure that out. Then run a line to the regulator then to the fuel solenoid.

Then I could use the second outlet to feed the excess fuel back to the fuel cell.

As for the fuel pump shoud I use the painless PRF-50102 relay kit and a swith to run the carter pump.

Thanks, Josh