Larry what i have seen is this, when the nitrous hits the
first thing it does is cool the intake charge as it goes it.
The reason for this is it is -127 degrees F if you have
liquid nitrous. When it goes to gas it takes heat out of the
intake charge and makes room for itself up to a point. As an
aside to this when the nitrous is tuned correctly the EGT
should drop about 100 degrees when you are on the bottle. It
is really a matter of how much nitrous you use. It like most
things that add power is good up to a point and then you get
less results per unit added. My personal limit is 50% of
what the engine hp is without the nitrous. This number by
the way links to your observation on VE. for me after this
point you are adding nitrous to the point of limiting air
from however else it is getting in, carb, efi whatever...
For me practical limits sound like 350 hp for a sb engine
that is 300 to 370 inches and 600 hp from a BB of 500 and
up.. Others use more but the tuning gets so dicey that the
gain is generally not worth the constant explosions. You
also have to use a cam and headers that will flow what you
have for hp on the exhaust side of the engine too and it
becomes a very specialized piece that will not run as good
as a NA engine without the nitrous. Remember too when you
use this stuff that it is all 'bang' and no 'push'!! It is
the highest stress way to make power that I am aware of. All
the power is produced in a limited number of crankshaft
degrees, unlike a turbo :>) which has the least amount of
stress per hp produced.. How you put the nitrous in also has
some bearing on how well it works too. For me a plate system
over 250 hp is a bomb. I am sure many have had good results
with a 300 hp plate system and that is great! But
historically this is not the case. The reason for this is
the air flow of the intake manifold. If you have good
runners and bad ones then the good runners get more nitrous
too. so the hp added per cylinder is not the same. That
really does bad things trying to get the timing right and
makes the system very finicky as these air flow problems
come and go with rpm. A port system is better for
distribution but does not cool the intake charge as much so
the manifold fills up with nitrous. If I was working on a SB
engine I think for me I would run about 150 hp on a plate
and 200 hp worth of port injection.. Best of both worlds in
my mind. Turn the plate on first and then add the port
nozzles as you can use the power. For drag racing the spread
in turn on times might be milliseconds and for lsr might be
miles apart..
Dave Dahlgren ( who has both won and lost the nitrous wars)
DrMayf wrote:
>
> This question or series of questions relate to the use of squeeze or juice or
> nitrous and is for the motor heads who really do understand hoow it is used.
> Nothing trick here, no flames, just a dumb ignorant ex Alabama wienee with
> some questions. Normally aspirated motor...
>
> The motor is at full boogie heading down the track. The engine has been tuned
> pretty good so cylinder filling is good, well actually more than 100% due to
> ram tuning (yeah, I know that most cars have around 80% cylinder filling
> efficiency). So the air is really going into the motor. Now the nitrous hits:
> this stuff is a cold fluid that rapidly expands as a gas as it goes into the
> manifold along with the extra fuel. Now here is my funny question: since all
> the air that can be put into the cylinders is being put in there already how
> does the extra nitrous and fuel get in? Does the expansion of the NO2 act like
> a blower forcing more into the cylinders? If so, then how come it does not
> blow out the carb or throttle body? This is a puzzlement to me. I know it
> works but ...
>
> mayf
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