I am in the process of building a dedicated low fuel pressure nitrous fuel system for my car. I am using a Jaz 1 gallon fuel cell, -8an line to the filter, -8an to the fuel pump, -8an to the regulator, and -6an to the solenoid with a -4an return from a bypass regulator. I am running an NX single fogger with the potential to spray up to 400hp through a single fogger...I will be spraying a max of 300hp. I was looking at fuel pumps and came across the mallory comp140 with a bypass adjustable regulator for $240 from jegs and it seemed like a good quality pump. Are the mallory pumps a quality pump? What about the mallory regulator? Another question I called NX and they told me to run 10psi through the nitrous system and gave me updated jet sizes for my low pressure application....Do these jets sound right?
N2O Fuel
100hp 52 38
150hp 62 46
200hp 78 57
250hp 88 62
300hp 93 ??
350hp 110 ??
400hp 136 ??

I'm still waiting on them to get me the fuel jet sizes for the higher hp shots.

Thanks for any info/help
Matt

 

TTT...? Anyone...What about low psi vs high psi tuneups with a single fogger?...Ktamez?
Later
Matt

 

Matt,

We've had good luck on some mild 600ish hp Big Blocks, and the Comp140 would probably be fine. The regulator also works pretty well in most applications.

The pump I've been selecting as of late though has been Product Engineering's 270gph #4200. This pump has an output of ~20psi, which will lead to more stable delivery. It can be had just under $300. PE is a top notch company, and have been excellent ever since I started dealing with them.

The Mallory 140 comes with a bypass regulator, however I'd just dig up a Holley 12-803 regulator ($20-25 from most shops). This is a deadhead regulator. Also this makes the plumbing slightly less complicated (and a few less $15 AN fittings you have to buy ).

There have been two trains of thought on Deadhead vs. Bypass regulators, and I used to be on the other side, but after doing some more research, I like this deadhead regulator better. (Let me know if you want me to compare the two and the reasoning behind them).

As far as your nitrous jetting..... I honestly don't have any experience on what it looks like you're doing. I've personally never ran a single nozzle on a low pressure tuneup. What does this system consist of? I wouldn't recommend trying to run a 136N jet (Or anything larger then the 78 to be honest) in a single nozzle configuration. To the best of my knowledge no single nozzle will actually support that amount of nitrous.

If you are wanting to run settings as high as you are indicating, then I'd highly recommend an actual Direct Port system.

If this jet pattern you posted is for a Fogger system, then we have some even more serious problems .

Let me know what you've got planned.

 

Thanks for the reply and info!! I really appreciate it!

I was told that the bypass style regulator will keep the fuel pressure more constant and also bleed out the air in the fuel system before I actually spray. Is that true?

Please elaborate on the deadhead vs bypass regulator because anything that saves me money is better.

Dod you have any links to that pump that you recommended?

I am still debating on whether to go with the low psi setup or a high pressure setup...NX told me they have plenty of cars running the single nozzle at low pressures and have not had any problems with them....NX is where I got the jet sizes from for the low psi setup. Would there be any advantage to going with a high psi setup over the low psi setup?

The NX kit that I am running is a NX S.H.O. kit part # 20112-15. Go to www.nitrousexpress.com/welcome.htm and type in the part # if you want to check it out. It is a standard NX single fogger kit, like the LT1 kit, except it has bigger lines and a ported S.H.O. single fogger that NX says has been tested to 400hp with the 136 N2O jet.

Thanks again for the info
Matt

 

I honestly have no experience w/ the S.H.O. , so I can't help ya much there. I'll try and give you an idea on the fuel jets you'll need to run the right N/F ratio this evening (kinda short on time at the moment).

The Bypass regulators work on the idea that the fuel is always flowing, and so there won't be a time when the solenoid opens, that it essentially "emptys" the fuel supply that is on the solenoid/regulator. This is a good idea, and I really don't have any qualms about running one this way, as its been done with much success.

The Deadhead regulators however (including the Holley specifically), actually have pressure creep when the system isn't flowing (Solenoid closed). Sitting on the solenoid the pressure will rise above the pressure it is regulated down to when flowing to 20+ psi (depending on the pump). Once the solenoid opens you have a short high pressure burst, which will help fill the line(s) or Spray bars (depending on system). Remember, the Nitrous will move much quicker the fuel when the solenoids open. Once flowing the Holley Regulator is very precise down to its normal regulated pressure.

Either way will work. One of the nice things to add is an Air bleed system which will take the air out of the line between the regulator and solenoid. As you mentioned, you're trying to get the air out of that line, but when you turn the pump on, that air has nowhere to go except up against the solenoid. Even w/ a bypass regulator most of the air in the system will be pushed to the solenoid as the line is pressurized, then the excess will be bypassed to the tank by the regulator.

Here is some more info on the Product Engineering Pump:

http://www.producteng.com/PE_4300.htm

If you don't mind the extra plumbing of the pump bypass, the 4300 can give the same kind of volume, but is capable of a higher pump pressure, but the 4200 should suffice just fine.

You asked about the advantages of high vs. low pressure,.... Its kind of a split with me. The High pressure tuneups have their bonuses, but you'll be fine on a low pressure setup like you have now.

OK so much for a short post when I'm short on time LOL. I'll post back later this evening with some jets to run along with them big pills.... One thing for sure I could put rocks let alone dirt into your fuel system and it wouldn't clog up the jets hehe. a 136 jet is almost straight through hehe.

 

Thanks again for all of your help and info. That pump looks stout and I will probably get one from you early next week. Do those pumps come with mounting brackets?

I think I would rather run a deadhead regulator for the reasons that you gave above but what can be used to bleed the line of air before the solenoid?

Is the holley regulator that comes with the blue pump a good regulator to run?

What fuel pressure would you recommend for the system while the nitrous system is on...10psi??(that is what NX told me to run)

What type of fuel filter should I run?

Next, should I run an 8an line to the filter, then 8an to the pump. 6an from the pump to the regulator and 6 an from the regulator to the solenoid? Are these line sizes OK? What size line should I use going to the nozzle? The one that came with the kit is 3an I think. Is that big enough?

Sorry for all of the questions but I just want to make sure everything is perfect with the fuel system so I don't have an unexpected meltdowns due to skipping anything.

Again, thanks for your help
Matt

 

Also, what is the difference between internally bypassed and externally bypassed fuel pumps?
Matt

 

One last thing I just thought about....with the deadhead regulator and spraying a small shot (100-150) would it have the same pressure creep in the fuel pressure as it would with the solenoid being closed due to the size and volume of the pump and the small size of the fuel jets?

Matt

 

hey Matt... this sounds very complicated!

I'm glad you're trying it first in your car



Let me know when you're ready to put everything in, so I can give you a hand


talk to ya later
leo

 

Matt, Sorry for the delay, but I started doing some N/F calculations, and man, that .136 jet is just plain BIG. If you could actually flow the nitrous through the entire system, it comes out to alot more then 400hp.

I honestly don't see why a jet that large is needed.

The larger settings also seem abit lean IMO w/ N/F ratios in the 7:1 range. Ideally you'd wanna be in the 5s.

I'd bend someones ear at NX an double check this stuff, but I wouldn't feel comfortable with what they're showing you right now.

Theres a special fitting(s) to use that go directly in front of the solenoid(s). I honestly don't think an air bleed system is necessary for ya in reality. Its not like this is a Pro Mod car or anything.

The Reg. w/ the blue pump is the same one I mentioned above. It'll work fine.

NX's Standard low Pressure tuneups are 10psi, and tuneable downwards or upwards a pound or two.

Any decent filter should suffice, don't need to be terribly picky here. Just nothing with real fine screens. Once you have verified the tank/system is clean, I'd run the coarsest filter possible (usually a stainless type).

That all looks fine, except the line going to the nozzle. This goes back to running 400hp through a single nozzle. I've never done it, and it just doesn't seem plausible. I'd talk to Ricky or Brian at NX and see if they can give you more info on some of these details.

The pressure creep will be the same regardless of jet.

The externally bypassed pumps simply have a return line going from the pump back to the tank, where the internal bypass ones don't.

I think I got everything there. Them jetmaps are just wonky man. Make sure to look into it.

 

Thanks Again for all of your help!! It is greatly appreciated. You have mail on the pump.
Later
Matt

 

BTW I called NX and they told me that the 3an nozzle line was the wrong line and to send it in for an exchange to a 4an line.
Later
Matt