Adding NOS, using existing fuel line, which pump?

[Hybridized]

The current system has a 5 gallon fuel cell with two 3/8" lines from cell to 2 Holley Blue pumps (I modded 'em to be self-regulating at 7 psi). The pumps' output Ys into a 1/2" fuel line, goes to a cool can and off to the carb.

I'm adding NOS (150 HP shot). My thoughts are to tee into the existing fuel line to a mechanical fuel pump (for some extra pressure) and then to the NOS fuel solenoid.

Will a stock pump work at the higher RPM's (6000-7000) without "pump-arm float"? What mechanical fuel pump would you recommend?

This is a drag car only, 11.01 at 122 MPH (5800' altitude)

I'm adding the mechanical pump because I've noticed fuel pump pressure at 3-5 psi at the end of the track.

I'm getting plenty of fuel.

[crankshaftkid]

Are you going to slam the ones who try to help here too?

[cuda66273]

I guess I'm just old and crotchity, but I don't understand why anyone would want to run Nitrous?

I'm not slamming you, just making an observation, your running 11's at 120. It would just seem to me a more economical route would be to build more engine HP, heads, compression, cam, oil control.

One of my racing buddy's put a 150 shot on his 350/335HP crate Chebby and he regrets it ever since...cheap HP....I don't think so, he ended up spending around $1400 getting it to work kinda right and now he spends about 60-80 bucks a day on gas.

Last year he raced 16 times at say $70...thats a grand just for the gas!

What could he have done for $2400? and this year he's looking at another $1000 or more so were up to $3400.....and his plugs are speckled with piston......I think it's a grenade with the pin pulled, he has begged me to help him get the car consistant and I refuse to work on it.

Now my Brother runs the gas and he needs it, 700 Cubic Inch Cozzy headed Fird in a 66 Mustang, 208 MPH at 6.81 ET......but he won't race me on a handicap tree, he knows he can never get it consistant enough to run the number and I'd cut him down at the tree every time...typical Fird boy, no gut's no glory....LOL...sorry Bro...

[crankshaftkid]

I have never been a big fan of gas but it can/does have it's place. I'd love to have a 75 shot on my totally stock V6 Dakota but then, I'd have to have the bottle within reach to turn it on etc. At the track, I've seen it used only to 'nudge' the other guy on the top end...like if you leave first and the other person catches you, hit it for an instant and get your fender back out on them. They'll usually break out trying to get back on ya. This is especially usefull on the 'slower' cars but can work with the faster brackets too. Over the years I've come to look at it as another tool to use but if you become a NOS junkie and use it with no restraint, well, money will be spent.

[Hybridized]

Originally posted by crankshaftkid
Are you going to slam the ones who try to help here too?

Try it the other way. I was getting slammed first (multiple times) and I got sick of it.

It actually took a Camaro board to convince me what is the correct way and why. Take a look how persuasion is done with intelligence, not ignorance and name calling.

http://www.nastyz28.com/ubb/Forum8/HTML/002758.html


All I was asking why at the Moparts.com board and got repeatedly slammed.

[Rob Voyles CA]

if people don't agree with you....that doesn't mean they're slamming you.

[Hybridized]

To cuda66273

I have all the NOS gear. Running a 150 HP shot will put me in the 10.5 region.

To bump up my current engine to 650 hp??? I'd have to go with aftermarket cylinder heads, ported, matching intake..... Plus I'm running 13.5:1 pop-ups designed around a 906 heads. New pistons, machine work, yada yada yada.

Bottom line, it would cost me $5k easy to get upto 650 hp (low 10s).

NOS would only be used for adding the occasional "ye-haw" effect. I would not compete with NOS.... This is in bracket class and consistancy is the name of the game. But there has been a few times where an extra "kick" in the pants could of made the difference.

I'm also heading down to a lower altitude track in late spring. The car with altitude correction, will run a ~10.4. I would love to do a final run dipping into the 9s!!!!



You may max out your credit card to gain that 0.5 second, but I'll use what I have to maximize my HP.

If I isolate the two pumps, raise their pressure upto 12-14 psi, and regulate it back down to 5-7 psi, I should have an adequate fuel supply system for both the carb and NOS.

$150 or $5k and engine R&R.

I'll pick the $150 for that +0.5 second.

[Hybridized]

Originally posted by Rob Voyles CA
if people don't agree with you....that doesn't mean they're slamming you.

But calling me a block-head, idiot and stupid is.

[Rob Voyles CA]

I didn't see that....if that happened that was wrong. It got wacked before I read the other replies.

[moparguy01]

Keep in mind you wont get into the 10's if you just put 650 horsepower there. You gotta deal with chassis problems and launching and stuff like that. You can have all the power in the world and it dont mean a thing if you cant hook.

good 1/4 times dont come from smoking the tires down the entire track.

moparguy

[Hybridized]

I think 11.01 is not too far from the 10's.

I won't launch with NOS. Maybe bring it on after the 1-2 shift (auto).

[Dart_440]

Im running a similar fuel system as you and I was running a 200 or so shot through my Hyperutectic *GASP!* piston 440 and it worked just fine! never had 1 problem with the fuel system at all once I sumped the tank. the only difference I did was I added a fuel log and a Barry grant bypass regulator. I also placed a holley blue regulator at the end of the fuel log and put that to the nitrous fuel silenoid. I wouldnt ever think of a mechanical pump for a nitrous fuel system.
I would spend the money and run a return line, its worth the money because you always have cool fuel at the motor and it doesnt strain the pumps because it sends the access fuel back to the tank.
You should set the pressure at 7 lbs or so for your carb and also set the holley blue reg at 5.5 lbs and that was the trick setup!
If ya have anymore questions e-mail me Dart_440@hotmail.com

[Hybridized]

With all the opinions given from multiple boards, and a very convincing post at another site...

http://www.nastyz28.com/ubb/Forum8/HTML/002758.html

....I'm ditching the idea of using a mechanical pump for pressure increase. A mechanical pump is a pulsation source, and that would be a poor choice for dialing in a NOS system.

I will run two pumps into one 1/2" line. I will isolate each pump and raise the fuel pressure up to 10-14 psi. The higher pump pressure will compensate for the 6 psi of pressure applied to the horizontal column of fuel under acceleration.

I like the idea of two pumps. There is a backup if one fails. One pump should be enough by itself, but barely.

I'll regulated the fuel with a non return style regulator. Since the pumps are only on for a brief time (under a minute) and fuel goes thru a cool can, I don't feel that it is necessary to return excess fuel to the fuel cell.

Big Holley regulator



I don't trust this small Holley regulator for the entire system. It regulates all the fuel thru a 1/4" orifice with a checkball and spring covering that orifice.




The system that I have has three settings; 50 hp, 100 hp, and 150 hp. I'll start with the 50 hp go up from there.


A sanity check. I have about 500 hp at the crank, +150 hp with NOS. That comes out to 650 hp. With a BSFC of 0.5 lb*hr/hp and fuel weighing 6 pounds to the gallon, the demand on the fuel system is about 55 GPH.

The current system flows twice this. So a factor of safety of 2.