what size fuel line for nitrous setup?

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72Dodge

72Dodge

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I'm not installing nitrous on my car yet, but when I install the fuel cell and braided hose/AN fittings, I want to make sure I use the appropriate size to install nitrous later.

I know a little about nitrous, but don't want to go all out learning everything right now, because I'll forget most of it by the time I get around to installing it later :)

Car would be a small block Mopar, and I'll probably only use a 100 shot.

I see most fuel cells (at least most that I'm looking at) come with -8 AN outlet, but that seems way overkill to me, isn't it?

Should I go with -6 braided line from cell to pump then to carb, or is even -4 (or ?) big enough for my application?

Also, after answering that, if I go to a big block with a larger shot later, would whatever is recommended still be big enough?

Any recommendations very welcome... thanks!
 
-8 from cell to regulator would be what I would use. Then -6 to carb and N2O fuel solenoid.

Pump gas and a smaller shot, <150 hp, you can likely use a 140gph pump.

You'll need two regulators. One for the carb and one for the juice.
 
images
just use 1/2 aluminum hard line...summit /jeggs.
bend it ,,,route it and use brackets to hold it..much better and cheaper than dash 8 from the tank to the front of the car....fwiw..
 
Cheapstreetduster said:
images
just use 1/2 aluminum hard line...summit /jeggs.
bend it ,,,route it and use brackets to hold it..much better and cheaper than dash 8 from the tank to the front of the car....fwiw..
Click to expand...

Yeah, I was thinking about hard line for the main length of the car as well. Seems like it woudl be best. I'll just need to use the braided from hose to electric pump and so on. My main concern was just what size to use... I didn't want to go overkill.

Last night I actually decided for now to just use the stock tank and lines to get the car on the road, then change over to the cell and appropriate plumbing later.

Thank you for your help.
 
remember that the large the diameter of the fuel the more powerful the fuel pump has to be to over come the weight to the fuel in the line. I your case a holey blue or black pump and 3/8' hardline or #6an is big enough. use a #8an out of the cell to the filter and to the pump then 1 size smaller the rest of the way to the regulators.
 
Assuming that I did the math right the difference in weight of fuel between a full 3/8" tube and a full 1/2" tube over a 15' length is .067 lbs.

Since drag racing appears to be the plan I'd go with the 1/2" tube.

I make brackets for bulkhead union AN fittings at each end of the fuel tube. That gives a secure end to the tube and a good way to make the transition from tube to hose.

If you use the aluminum tubing make sure to use an Adel clamp every 18" at most, and give the tube a little excess length in the form of an subtle S curve at each end if at all possible. Aluminum's thermal expansion is quite a bit larger than steel's. Adding the S curves allows it to grow and shrink w/o putting undue stress on it.
 
Thanks for all the tips guys. I've also been reading everything I can find, and it's all starting to make a little more sense. I still have yet to find one single source of solid information about this topic, but I've been piecing it together from here and there. I'm surprised that the Mopar Performance books don't seem to go into this in more detail. I think I'm starting to get it though.

This isn't for a full race car, just a street/strip car with probably a slight emphasis on strip as opposed to any sort of creature comforts :) The car is a Mirada, so there's plenty of room to work with in that cavernous trunk!
 
When it comes to fuel, it's better to have too much reserve than not enough.

A 140gph pump and 1/2" or -8 line works well for most any street car. If you start pounding juice, then you may need to rethink the pump size, a 1/2" or -8 line will provide enough fuel for some pretty serious HP.

You could even go -8 from cell to pump , then 3/8 or -6 to regulator and carb. I wouldn't do it, but, it's an option.

My attitude, if you are going to do the lines, put 1/2" in so you don't potentially have to do the work twice.
 
Yes, I will go a little over what I currently need, because I want it to be upgradeable later, should I decide to go big block, big juice etc. That was my intention from the start, to not have to re-do stuff later... make the car upgradable. I just wasn't sure what was completely overkill (like just flat out wouldn't work) and so on.

Thanks again.
 
Yeah I think it will be pretty cool. Here are pics of when I first got it. A lot of things were done wrong on it, so I'm making them right, but it was complete except drive train. It won't look like this when done, it will be black and will have different rear spoiler. Not sure yet if keeping the scoop. Just my toy to mess with and make it the way I want it.

Best part is hardly a spec of rust anywhere. Texas car until about 2009 and off the road for over half the time since then.

Wheels on it now are Imperial.
 

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go with a minimum of a 140gph pump.
1) run -10 from cell to filter
2) run -10 from filter to pump
3) run -10 braided or 1/2" aluminum hard line from pump to a Y-block or fuel log of some kind that you can mount fuel regulators to
4) fuel regulator with 2 -6 lines to carb
5) fuel regulator with 1 -6 line to Im guessing a plate NOS kit, and leave the other outlet of that regulator available for flowing you fuel pressure for the NOS kit.

doing this will give you room for growing.
4
 
It is always better to run a separate pump for the NOS setup. I never run the motor and my NOS off the same pump. Also look into putting a filter on the nos solenoid also. You do not need anything getting in there and hanging one open.

Been running NOS on cars since the mid 90's when I was running 3 kits on my 10.5 car.
 
Thanks guys. Appreciate all the advice. Will help me plan things the best for my needs right from the start.
 
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