I'm running the nitrous works 125-300 plate system, I have it setup with a toggle switch to arm it, but I am using a full throttle micro switch on the carb to trigger it, I'm not quite sure if anyone has tried this type of setup, or if you prefer to trigger it by hand off your shifter?
I elected to run it through the nitrous mastermind computer. Not sure if anyone has used this setup also.

I am running a separate fuel system for the nitrous enrichment, so I should not have any problems there. Although the fuel system is separated from the carburetors fuel delivery, it still comes from the same cell (no different fuel)

a window switch to activate it would be my preferance...toggle it on, and let the window switch turn the nitrous on at the same rpm everytime and shut it off at the same rpm everytime just incase there is a prob. Have a driveshaft break half track and nitrous is still engaged...quick way to loose an engine.

Before you start, make sure to have a bottle heater and pressure
gauge, along with a fuel pressure gauge and regulator for the nitrous
enrichment. A good ignition system is also mandatory... one that
doesn't keep advancing the timing to the moon as the engine revs.
It should STOP at around 36 degrees total. (with the nitrous off)
Check it!!!!!! Wild advance KILLS nitroused engines...
Factory distributors are really bad about this.

Mostly geared to a carb system, but applies to all.... Here Goes!!!

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Now that we've got the juice, how do we have fun with it?

Well first off, you don't want to get anxious and hurt your
engine... Once the system is properly installed, check to
be sure its fuel enrichment is working properly. Turn the
nitrous bottle off, arm the system, and with the revs around
3000 rpm, tap the button. The engine should fall on it's
face. It should be about like hitting a kill button.

Now that we know it works (the engine is getting enrichment fuel).
Let's see what other items are necessary...

-COLDER spark plugs! Do NOT use Split Fires! For the street,
use the coldest non racing plug you can find... especially
if you might have to use the system with pump gas.

-A bottle heater and pressure gauge! You MUST know what your
bottle pressure is to get consistent results! The gauge tells
you the pressure, the heater allows you to control it. Keep it
around 900 psi for best performance.

-Fuel... Use the BEST you can find! Detonation on nitrous can
lead to some VERY un-pretty things! Straight pump gas should
not be used on systems over 125hp on a 302. These engines with
their 10 7/16" head bolts are prime game for blown head gaskets
if everything isn't right. A little detonation goes a loong way
on these motors...

Make sure you have a good ignition system with good wires.

**** Now that you are set up, how is it tuned???????? ****

First is timing. The timing NEEDS to be retarded about 3
degrees for every 50hp of nitrous boost. If you don't, it's
bye-bye head gaskets, or worse! You need to go with the upper
end of this scale when pump gas is used (even if you add octane
booster). Just DO IT!!!!! I use MSD's Multi-Step Retard to
do this automatically anytime the nitrous is engaged.
If you are in the market for an ignition system, The MSD Digital 6 Plus
costs $279, has a timing retard, a two step rev limiter, plus
is adjusted by little dials. (instead of chips)

******** FUEL SYSTEM ********

To start, make SURE your fuel system is able to maintain
full fuel pressure at full throttle high rpm with the
nitrous engaged! It's better to be safe than sorry here.
I've seen cars break into the 10's with a single Mallory
140 or Holley Blue pump, but wouldn't really recommend it.
I use two Mallory 140's on my car. One for the engine, the
other for the nitrous.

******** FUEL PRESSURE ********

If the fuel pressure is too high, the car will exhale a bunch
of black smoke out the exhaust, and will not run anywhere near
its potential. It will feel very lazy (well, for nitrous).
We want to lean it out, just not toooo far.
My buddy's 2V 351C Mach I went from 9.00 to 8.50 in the 1/8,
just from lowering the fuel pressure!

Start with the smallest hp jets, with the fuel pressure turned
up extra high. This will ensure an extra margin of safety.
With the tranny in neutral (park), bring the revs up to 3000
and tap the button. The revs should jump up a bit. Probably
not super crisp or fast... just kind of a 'VROOOOM'. Do this
with the bottle pressure at its operating range. (850-950 psi)

If it hits EXTRA hard, like BAM! You are probably a bit lean,
and need to increase the fuel pressure.

We can now start to decrease the fuel pressure....
Do this with the car in neutral. Starting with the pressure
high, we are going to be tapping the button at 3000 rpm as we
gradually decrease the fuel pressure.

As the fuel pressure is lowered, the engine will start to respond with
increasing aggressiveness. The VROOOOOM will start to turn into
a BANG! When it BEGINS to get pretty crisp, it's time for a road test!

At full throttle around 3500 rpm, hit the button and hold it
for 3-4 seconds. The car should respond in a positive manner.
As you let off the button, kill the engine, coast to a stop,
and check the plugs. They should look clean, but have NO specks
on the porcelain. If they do, it's aluminum from the pistons,
and the fuel pressure needs to be increased. Chances are, at
this point it will still be a little rich, and you will find no specks.

Decrease the fuel pressure a little at a time while making the
above test. As soon as you begin to see ANY specks on the plugs,
raise the fuel pressure a half pound or so, and you should be
close to optimum for that hp level. If you want to try other
jets, you need to go through this same testing procedure again.
Start rich, and work your way down.

You will be **AMAZED** at how much better a nitrous system works
once the fuel pressure has been optimized!

**** Other things that help optimize a nitrous equipped car ****

- A good exhaust. BIGGER is BETTER! 3" pipe and mandrel
bends rule in nitrous applications!

- Proper camshaft. A lobe separation around 110 deg is a
good compromise on a carbed street engine.
Some extra exhaust duration is also a plus.
8-12 extra degrees is good. To maximize
nitrous performance, go to 112. 114 on an
EFI car.

- Compression. Low compression makes tuning a lot more
forgiving. Make the same mistake with both
a high and low compression engine, and your
chances of living through it are MUCH better
with the lower compression.

If an engine is a little low on compression
anyway, (5.0 with a cam for example) nitrous
can bring in a SERIOUS wake-up call!

Good Luck, and HAVE FUN!!!!!

------------------
Alex Denysenko
Co-Administrator and Moderator

NHRA/IHRA/SRA member and licensed Superstock driver
MCA member# 53321
NHRA and IHRA SS/LA & SS/MA National Record Holder '00,'01,'02,'03,& '04
First SS/MA in the TENS!
IHRA division 5 Superstock Champion
Fleet of FoMoCo products including 88 ASC McLaren Mustang #28

The Barry of BarrysGrrl

I will use the bottle heater & gauge combo also.

You didn't address my delivery though; am I ok running a full-throttle activated micro switch as opposed to manually triggering it?

I also had an NOS brand purge valve. It was the only other part of the system I had problems with. Entry level NOS brand stuff is JUNK. It was designed over 20 years ago, and is lightweight plastic. It is geared more toward making profits than horsepower. Their higher end stuff is okay. Just stay away from their Sniper, Powershot and Cheater systems.

Those progressive controllers work by buzzing the solonoids off and on really fast. If you want to pound the seal out of a solonoid out PRONTO, buy one of these.

Wide open throttle switches are great. I've got a 3-way switch on my car. I can choose 'off', 'button', or 'throttle' mode. The button works well on the street, and throttle mode is handy at the track.

Good Luck!

quote:

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Originally posted by n2oMike:
I've used those fuel pressure safety switches sold by NOS. They were more trouble than they were worth. I finally just removed them.

I also had an NOS brand purge valve. It was the only other part of the system I had problems with. Entry level NOS brand stuff is [b]JUNK. It was designed over 20 years ago, and is lightweight plastic. It is geared more toward making profits than horsepower. Their higher end stuff is okay. Just stay away from their Sniper, Powershot and Cheater systems.

Those progressive controllers work by buzzing the solonoids off and on really fast. If you want to pound the seal out of a solonoid out PRONTO, buy one of these.

Wide open throttle switches are great. I've got a 3-way switch on my car. I can choose 'off', 'button', or 'throttle' mode. The button works well on the street, and throttle mode is handy at the track.

Good Luck!

[/B]

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OH TOO COOL! I get it, you have a 3 position switch, where you choose how you want to run... I LIKE IT! I'm gonna have to do that, it will be simple-pimple too, just change out my existing "arming toggle" and replace it with a 3 position and run an extra wire for the button. WOOOOHOOOO, thanks!

P.S. You don't have to pulse those solenoids, you can set the computer to hit 100% if you wish.

quote:

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Originally posted by 654212spd:
mike how about none extended tip plugs

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Non-extended tip plugs are good. Extended tip units can turn into little 'glow plugs' when the going gets hot.

Good Luck!

Nitrous follows the 'Law Of Diminishing Returns'.

You'll get a LOT more out of that first 100hp than the next 100hp, and so on. You CAN really abuse an engine with nitrous. They key is moderation, and to build a good combination.

I did help tune a friend's 89' 426 stroker that used an offset ground 400 crank, chrysler rods and Probe pistons to go 5.92 @ 119 in the 1/8 on two stages of nitrous. We pulled PLENTY of timing out, and the engine went two seasons before he took it out and sold it. He sprayed no more than 400hp total.

Of course 'heads-up' racers will push the envelope more than I will. I don't like working on cars enough to continually tear them apart and buy new stuff all the time for that last tenth of a second. I'm competitive, but not THAT competitive.

Good Luck!