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