what is the ration of bar to psi?

 

That's a good queation. . . . I would like to know that myself. . . . any Math Professors out there?

 

1Bar= 14.5psi

 

damn nm i was too slow


[Modified by Mikex25, 7:09 AM 10/30/2001]

 

1 bar equals 14.5 or 14.7? I thought it was 14.7

 

Its 14.5. 14.7 is atmospheric pressure.

 

and on the boost gauges....isnt it kg/cm2 or some ****? isnt that 14.22 ?

 

it's 14.7

 

.5 bar = 7.35 psi of boost
1.0 bar = 14.70 psi of boost
EVIL

 

^ You are mistaken.

1 bar =14.503 psi
1 atm=14.695 psi

 

anothre good question kg/cm2 how many psi is that? is it the same as one bar?

 

1 kg/cm2 = 14.22psi

 

mayo or miracle whip??
14.5 --- 14.7 same difference j/k

 

ok so 14.5psi..

why have two different levels of measuring boost?
whats the deal

 

one is for us metric challenged peeps and the otehr one is for the rest of the world..

 

yes. 14.5.

inHg, mmHg, bar, psi...all developed by different people to measure the same thing.

kinda like inches and centimeters.

 

The pressure ratio is the total absolute pressure produced by the turbo divided by atomspheric pressure. Absolute pressure means the amount of pressure above nothing at all. Nothing at all is zero absolute, so atomspheric is 14.7 absolute. 2 psi boost becomes 16.7 absolute, 5 psi is 19.7 absolute, and so on. Total absolute pressure is then whatever the gauge reads plus 14.7. The pressure ratio thus becomes a reflection of the number of atomspheres of pressure generated.

Pressure ratio= (14.7 + boost)/14.7
Ex: for 5 psi
PR= (14.7 + 5)/14.7 = 1.34

In this example approximately 34% more air will go into the engine than the engine could have consumed by itself.

PR= (14.7 + 12)/14.7= 1.82

Here approximately 82% more air will be going through the system. Pressure is also measured in bar, short for barometric ( 1bar=14.7 psi).

-From our friend Corky Bell

 

Thanks 98hx, I always thought that bar itself stood for "barometric", i.e. static barometric pressure, hence 1bar is 100% atmospheric pressure, which is 14.7psi at sea level. Less at higher altitudes. So .5bar = 7.35psi being that .5 or 50% bar = 1/2 barometric/atmospheric pressure at sea level which is 14.7psi. (14.7psi x 50% = 7.35psi is the same as 1bar x .5bar = .5 bar) I know it seems confusing but reading it over leads you to see it's really easy actually.


[Modified by VTC_CiViC, 1:05 PM 10/30/2001]

 

OK, so how many inches (or mm of mercury) is equal to "standard" atmospheric pressure?

30" of water (or Hg i.e., mercury, I forget which) = one atmosphere (one bar, 14.7 psi) ?

 

http://www.joshmadison.com/software/...t/download.asp

I'll bet none of you knew that so many different units existed.

 

why do people keep turning this into an argument? This is getting worse than the Quaife/KAAZ bumble-clot conversations. Art gave the correct answer a long time ago.

atmospheric pressure = 14.7psi
1bar = 14.5 psi
1kgcm = 14.22 psi

 

I use this neat java webpage which has Bar = kg/cm2 = psi converter.
http://www.worldwidemetric.com/metcal.htm

works really well...

liam