anybody think that it's normal for the introduction of nitrous to my intercooler , with about half of 12 feet still to travel in the plumbing before it reaches the throttle body , to cause the manifold pressure jump from 6 lbs to over 25 lbs ? i'm using a pair of .018 jets ( 2 ) in two saab intercoolers linked together.

the old setup had a single .034 in the cold air intake but i never had a gauge then......anyone out there using a pressure gauge on a normally aspirated B18 using nos ? does it cause high pressures in addition to adding oxygen ?

of course using a supercharger with a sealed forced air intake could be the difference - the gas is just expanding in a closed container.
most of the time no one knows what thier cylinder pressures or manifold pressures are with nos because they arent thinking to look for pressure....turbo/supercharger folks are consumed by boost pressure.
if i had run a dirrect port nitrous system i'd be right in there with the obliviouse - no knowledge of pressure due to nos because it would all have ocurred AFTER the manifold pressure gauge .

anyone either experiment or have technical knowledge on this subject - it is deffinetly happening - no doubt about it , and them are some dangerously high numbers for boost pressure.

anatolia

 

hi everyone! i would like to ask you guys if you know anything about my prior post :'manifold pressure with nos'

not whether it's there for you to see or not (i wrote it...it's there) but rather if you have anything constructive to add to it.
that's my question.
and if you do then you have my heart warming invitation to respond.

thank you all.

 

:closed:

you could of just replied to your own post with "ttt"

 

WTF are you trying to ask here? What kinda set up you got to be asking this question because Im reading stuff about a turbo, supercharger, and n/a setup . Well FI people do use boost guages to measure the amount of boost in the charge pipe if thats what your asking for...

 

I would think the difference in the charged air would make the pressure jump. Seeing how it is so much more dense due to the temp of the air, I would believe the manifold pressure would increase greatly.

 

so the sleeper comes through with an ACTUALL ANSWER ! right or wrong an inteligent response none the less. well mr. sleep i agree about the density of the air , but your not suggesting that the pressure came as a result of adding that much pressure in the typical sense...example - if i had introduced compressed air the exact same way it would not have affected the airs density or pressure - yes/no what is the true definition of density when it comes to air...more in the same space = pressure ?

 

hey neat , i'll try that next time. you're a real asset here thanks

 

true definition of density when it comes to air...more in the same space = pressure ?

if the volume (space) stays the same then the density does not change. instead the pressure would go up.

this is putting it really simple.

 

i realize this may be going out on a limb ( by the way thanks for your response ) i'm trying to rule out the pressure being higher as a result of a 900 lbs pressure tank expelling whatever it can through two .018 jets....one would think that could not be much in the traditional sense , however because it's nos it does cause the air to become more dense ....either way it's still the same thing to the engine - is that a fair assumption ?

 

well the manifold is not really a closed system right? you're talking about a dry setup not wet/direct port.

I would think you would have to find out how much nitrous is being expelled out of the two jets per second at a steady tank pressure of 900lbs. but with nitrous you're increasing the number of oxygen molecules chemically (in a sense), which with a a s/c, turbo you are increasing the number of oxygen molecules by increasing the pressure of the air.

I would guess that with a nitrous system the pressure of the manifold would not increase significantly if any.