100SHOT first time user

[Guest]

[joey11]

i'm contemplating using some spray on my current motor. it's a stock bottom end, recently rebuilt. what are the chances of me fucking something up if my tuning is safe with a 100 shot on 93 octane. i've never used it before but i think i can use it safely with such a small shot. i've gotten pretty good at reading plugs for N/A but i'm sure it's a whole other learning experience on the bottle

[mj88stang]

i've sprayed 150hp shot on a 100% stock 5.0l. you'll be fine, just start at 50 or 75hp and work your way up.

[347HO]

I suggest spraying all you got but;
Back your "all in" timing to what is suggested by the manufacturer.  I'd hate to suggest a pt and you blame me for a ruined engine.
Run it really fat till you got the timing close
Don't run it "full pass" until you feel the tune is at least good.

Are you changing plug range?  This will affect everything from the get go.

[joey11]

i would never blame anyone for ruining my motor if i installed it, you guys just give advice and it's my fault if something happens. i know the stakes when playing with this stuff

my timing is locked out so i would probably drop it to 28-30degrees on the bottle or whatever the directions suggest, i'm running AR3924's now which should be good because the AR3923's won't run in my car N/A...too cold.

as far as fuel supply goes, do i have to have a dedicated pump/regulator for the nitrous system?  or can i run what i have now(aeromotive a1000 pump and holley regulator) since it's a small shot of nitrous. i will have to straighten out my pressure dropping problem before i add juice. when i accelerate the f/p drops to like 3-4pds...not good when spraying

what is a good nitrous system brand also. i have not decided on manufacturer yet either

[347HO]

what is a good nitrous system brand also. i have not decided on manufacturer yet either

Today...  aren't they all good?
I don't know...   seems it comes down to the "user's" preferences on the equipment used.

[joey11]

they all pretty much look the same, i guess i'll shut my eyes and point.

[scienceguy]

Here is some basic nitrous tuning tips I've posted in the past.

Below are some tips for basic nitrous tuning.

-------------------------------------------------

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 2-3
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.
To maximize nitrous performance, go to around a 114 LSA with a
longer duration exhaust lobe, and install it 6-8 degrees advanced. 
(these are very rough figures, but give you an idea)

Of course, nitrous will still work just fine with a n/a cam as long as the
cylinder pressur isn't pushed through the roof.  Then you've got to be
VERY careful.

- 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!!!!!

[joey11]

that is some awesome advice.  thanks science guy

now for the fuel system, do i run a seperate pump and fuel cell for the system? i wouldn't think so or do i run 2 pumps inline with a y-fitting splitting between the carb and nitrous? and fuel pressure is to be max 8psi for my pro systems carb, do i use the same fuel pressure for the nitrous line regulator? or am i completely off base here

[juiced coupe]

You need a separate regulator for the nitrous side. A good single pump works just as good as two smaller pumps.

The fuel pressure of the nitrous system will be determined by the systems jetting. Manufacturers directions will dictate this. Most systems run in the 5-8# area while others run 10+ .

My baseline setup for a SBF  with a 100 shot is 28* timing with a NGK -8 plug. For your TFS heads, use a R-5671A-8 (stock # 4554). The plugs you mentioned are a projected tip design and are not recommended for nitrous.

[joey11]

you guys are awesome, i did alot of reading before i asked the questions so i had a basic grasp on how to tune on spray. now i just have to pick out a kit and install it. i already have a spare holley regulator that i can use and the car had a kit on it when i bought it so all teh mounting shit is still there.

will i have any problems blowing through my convertor with it being a 5300stall?

[juiced coupe]

will i have any problems blowing through my convertor with it being a 5300stall?

It will be noticeable, but shouldn't be too bad with just a 100 shot.

[joey11]

i think i'm gonna run just 1/8th mile passes when on the bottle to get used to it first. will too much fuel also be bad when spraying?  i would think it would be almost as bad as too lean

i was over on yellowbullet and they have a 20 page sticky on people showing their burned pistons from nitrous even though it could happen with a blower or turbo it just seems easier to do it with spray

[juiced coupe]

I have seen more pistons hurt by being overly rich than lean. Lowered timing and extra octane go a long way. Too much timing will take things out in a hurry.

[Will731]

How would nitrous respond to 108 lsa?

[juiced coupe]

How would nitrous respond to 108 lsa?

It depends on everything else. LSA is nothing more than a resulting factor in cam design. Put the open and close points where they need to be and the LSA will be whatever it is. LSA should never be a design factor.