Ok guys. I am new to the spray so bear with me. I just picked up a NX hitman kit from a guy here on TGO. Everything looks like it is in good condition.

I know how to install everyhing when the times comes exept I am a bit torn between 2 ideas I have for the fuel.

Should I get a fuel regulator that has a port for me to tap into, or can I just run another line from my fuel cell. The sump on the cell has 2 ports, so the motor is only using one. I have the other plugged.

Please fill me in if this idea of using the other port is bad. THX.

 

NX's instructions say not to use the same regulator used for the motor. If you have a strong fuel pump and big supply line you could use a Y-block with 2 different regulators or do like you said and run a new line with a 2nd pump.

 

that second pump can be pretty week right. I would use a quality part, but I don't need anything fancy right? And should I have that second pump hooked up to the arming switch? Cuz it is not needed ever unless I am using the N2O. Thanks for the reply.

 

You could use a Holley Blue pump and regulator. They're a little over $100 new or you can find them used in good shape almost anywhere. I have a 3 gallon fuel cell mounted up front with a blue pump and regulator ...works great.

 

with the failure rate holley pumps have, id be SURE to use a fuel pressure safety switch.. lol.

 

Is this really true??? I have $, should I just get a different pump? What is reliable? I don't plan on using the N2O very often at all. So the pump needs to be able to sit for a while if need be. I would rather spend more and save myself in the long run. Thx

 

using a safety switch is a no brainer. You gotta keep in mind that you'll only have the pump running for less than a minute at a time... It'll last forever. The blue pump I have is atleast 10 years old.

What size fuel lines do you have for the motor? and what pump? You could always go the single pump route with the y-block. I'd use 1/2" or bigger lines and a Mallory Comp 250 pump.

 

I will have to get back to you on the pump. I am having the motor built now. It is going to be a 500 hp 383. Aluminum trickflow heads, all forged and internally balanced. full roller motor. with a 750 DP.

After thinking about it for a bit. i am just using the stock fuel lines that the TPI had. Are these gonna be too small??? The fuel cell I am running has 8 AN fittings on it I believe, maybe 6. I am at work and cannot check right now.

I am gonna be running a mech fuel pump. And maybe an electric for the N2O.

If I run nice big lines, is it easier to just use the Y. And I should not run it out the regulator??? how come?
Thanks for the help.

 

How exactly do you plan on running 1 pump and 2 regulators? Assuming that this thing is fuel injected (his car domain page shows a TPI engine) it has a bypass regulator (even if he’s swapping to a carb, as long as it’s got the stock pump in the tank he’s going to have to run a bypass regulator). Everything between the pump and the regulator will be at the bypass pressure. If you put a Y in there and 2 regulators, BOTH sides of the Y will be at whatever pressure the lower regulator is set to.

If you want to run 2 regulators, you essentially end up running 2 separate fuel systems, or a low pressure pump and an old school, carbureted type FPR.

If you plan on running the N2O at a different pressure then the engine’s fuel system you pretty much have to run 2 separate fuel systems. You could in theory get away with running a much lower pressure (less then 50% of the rest of the fuel system) regulator in the return line and use that to feed the N2O, but I don’t know that I would trust that.

If it was me, I’d either run the N2O off of the same fuel system that the rest of the engine runs off of with a good pump and a bypass regulator or I would run it completely separate, with a small fuel cell (race gas?), pump, regulator…

 

I am not gonna be running TPI. It is going to to be a carb. I have a fuel cell with 2 ports on the sump. 1 is going to feed the carb with a mech pump. The other port will be atached to an electric pump and go straight to the fuel solenoid. Weather it needs a regulator or not, I am not sure yet. Do you guys know? So essentially I will be running 2 seperate sytems. But instead of having a seperate fual cell, the 2 are just 1. Hope this made sence.

Any thoughts?

 

My $.02… no matter what you do I would make sure that the N2O feed is regulated. If you can’t rely on a specific pressure at the solenoid it will be impossible to run safely and get a good, consistent tune.

If it was me I’d still run a single system with a >3 port carb pressure regulator, run one line to the N2O and one to the carb. Otherwise, 2 separate regulators will allow you to use fuel pressure to tune the N2O without messing up the carb, but leads to a much more complex system to keep working correctly.