So this years winter project is going to be strapping a bottle to the 468. Motor currently is a 10.5:1, forged rotating assembly, studded, 4-bolt main motor. I've gotten used to it, so the N20 is where I'm headed. Car currently has a 950 Holley dialed in to the motor with a stock fuel pump. I was looking at adding a higher flowing mechanical pump as well. I am only looking at a 100-125 shot.

I know that I'll need more fuel. What's the best way to get it? Will fattening up the carb give me enough? I will also be looking into a new MSD box with the retard to pull timing. Does that sound like it will work, safely? Am I over-looking anything?

Thanks a lot,
Chris

The added fuel is distributed from the NOS plate.
You will need an auxillary electric pump, regulator, etc. to run the NOS kit.
You do not want to mess with the carb.
You may want to go to a few of the NOS companies website and research what is invloved. And suggested plumbing and wiring diagrams.

I have a sniper system on my 427. For the fuel side I just have an Edl race pump(for carb and nitrous), and that does just fine. I run the line to the nitrous side off of one side of my regulator.

I also have an MSD retard box, WOT switch, and rpm window switch, and fuel pressure switch(cuts the circuit if fuel psi drop below 4 1/2 psi--kind of overkill) for the nitrous side. It all works great. The retard box is really nice, since I don't have to adjust my timing when I run the nitrous.

The other thing is a purge kit. I don't have one, but that's nice too. I just crack the line near the nitrous selonoid when I'm a few cars back in line. However, on hot days it's a big problem, so I'd throw one in. In theory, at least, the fuel/nitrous ratio is set by the nitrous jets and should take care of that. But I'm no expert, and I'm sure there are about 14,000 guys on this forum who could tell you better than I can.

run a better mechanical fuel pump and your good

dont change your carb

for 100-125hp shot i wouldnt change anything besides race fuel

read about nitrous

for every 50hp you hsould retard the total timing 2 degrees

but on a 100 shot i would just run race fuel

900-1000 bottle psi very important

Don't do a mechanical pump with N2O.

You really need an electric pump and a bypass style regulator to properly control the amount of fuel added when you hit the button. With plans for only 100-125 HP of N2O you do not need to build separate fuel systems, just one good one with enough flow to supply the motor and N2O. Look for a fuel pump that flows 120-150 gph (I like the Aeromotive SS and matching bypass style regulator personally). I would also prefer 1/2" hard line and -8 braided line for the supply and return although 3/8 line may work OK.

Don't forget a good fuel filter and fuel pressure gauge.

???????????"Don't do a mechanical pump with N2O." ???????????

do what you like but there are many new mechanical pumps that are very good for what you are planning on doing

http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_745049_-1_10305

or you can block off the mechanical and get a electric and buy more parts to make it work

to each his own
putting on a better mechanical is the easiest way to go

for 100-150 shot stock fuel lines should be ok if youre under 500hp

after 500hp you should change the fuel line to -8 or -10 like mine and dont worry about fuel lines anymore

on a 100 shot put about 5 gallons race fuel and your ready to go

on a 100 shot with a good 60ft you should pick up atleast 5 tenths and 2-8 mph inprovement in the 1/4

we used to run our mustang on slicks bone stock it woudl go mid 14`s on a 150 shot we would go mid 12`s :)

That's what I said, don't use a mechanical fuel pump for nitrous.

What do you use with your nitrous setup?

An electric pump puts out the same volume regardless of RPM, a mechanical pump is dependent on engine RPM. How many gallons per hour do you think that mechanical pump puts out at idle? What if you hit the button off idle?