View Full Version : Psi / Bar
cmsmpau1
22-11-2002, 15:03
Hi All
I Apologise for being so lame and having to ask so many questions but i dont understand the Psi and Bar thing. I understand that a stock car runs at 0.7bar so is that 7 psi.
Ive just fitted my boost gague and its reaching around 6 - 7 psi. I take it thats not a good sign. Just need to know to see if the gauge is broke or even worse my turbo :(
Thanks
1 lb/sq in = 0.06805 atmospheres
I think that means 10.28psi
Mark
or in laymans terms
15psi = 1bar (its rough but gets u by)
cmsmpau1
22-11-2002, 15:15
So am i getting a usual reading then or is my car underperforming.
7 psi is spot on mate, s'only a low pressure turbo
chipped cars run circa 15psi
:cheers:
ibizacupra
22-11-2002, 16:03
1bar(g) = 14.5psi
7psi off your boost guage is (1/14.5)*7=0.48bar
~480millibar or 1480millibar if loggin using vagcom on boost.
Its fine for a standard motor.
No worries
regards
Bill
Dillinga
22-11-2002, 17:20
Probably another stupid question but.... I think I heard something about the boost gauge displaying how much extra air pressure is being applied on top of 'normal' atmosphere? Is this right?
Dormouse
22-11-2002, 17:42
BTW the R runs at about 11psi and gave 185ish BHP for that run on the VAG-COM (Ta Bill :p )
Dor.
ibizacupra
22-11-2002, 18:35
Originally posted by Dillinga
Probably another stupid question but.... I think I heard something about the boost gauge displaying how much extra air pressure is being applied on top of 'normal' atmosphere? Is this right?
The boost guage will read 0 psi/bar when engine off. This is in reality somewhere around 1000mb (weather depending - high pressure-low pressure type thing you see on weather maps)
+ve pressure is when the turbo's on "boost", ie spooled up and working.
-ve pressure (vacuum) is indicated on overrun, throttle closed, engine slowing down.
No such thing as a stupid question mate... ask away. Only way you get to learn things. :)
regards
Bill
cmsmpau1
22-11-2002, 21:17
Thanks to everyone who helped us on the Boost Gague. Its now fitted and ill post pics on monday.
Mark:D :car:
mark sheerin
22-11-2002, 23:55
Originally posted by ibizacupra
No such thing as a stupid question mate... ask away. Only way you get to learn things. :)
regards
Bill
Bill...do you floss?:)
mark sheerin
22-11-2002, 23:59
Bill....seriously...I can sense a new utility hatching for converting Bars to PSI or millibars or vica versa or any combination..(To add to my tyre and wheel and mpg utilities)
If someone has the difinitive conversion figures for me please !
Mark
:cheers:
Dormouse
23-11-2002, 00:06
Mark, you don't really need a utility to multiply by about 14 do you?
Dor.
P.S How about a single conversion utility all in one package rather than individual ones? now that would be useful.
mark sheerin
23-11-2002, 00:12
Sounds ok to me Dor.....anything else that could be included..
degrees C to farenheight perhaps...
I think I need a logarithmic one myself to convert my waste size to a trouser size:(
Oh jus thought.....bhp tp kw
etc
etc
Dormouse
23-11-2002, 00:27
Hmmm...yes, i just though that rather than having lots of individual ones a single utility to calculate lots of different car related things would be good.
off the top of my head i thought of a few extra.
kw - bhp
ftlb - nm
l/100km - mpg
etc.
Dor.
p.s if you are really clever, a intake temp to bhp variation would be superb!
ibizacupra
23-11-2002, 09:33
Originally posted by mark sheerin
Bill...do you floss?:)
LOL :laff:
Erm. No. :D
Bill
Mark - it's a good idea....and hence it's been thought of before :(
this site here (http://www.processassociates.com/process/convert/cf_all.htm) does conversions of practically anything into practically anything else (except water into wine, and gravel into gold ;) ).
You could "borrow" the concept and trim it down to car-related stuff only though (?) Would certainly be a good site resource! :afro:
chriskaven
23-11-2002, 09:48
I have a converter program at work which converts loads of different units Power, , pressure, weight, torque, speed etc etc. It is only a small .exe file. Who should i send it to to get it on the site??
ibizacupra
23-11-2002, 11:12
Originally posted by mark sheerin
Bill....seriously...I can sense a new utility hatching for converting Bars to PSI or millibars or vica versa or any combination..(To add to my tyre and wheel and mpg utilities)
If someone has the difinitive conversion figures for me please !
Mark
:cheers:
Here's a pressure calc sheet with some look ups for you.
Also bhp calc for info and torque from nm to lb/ft
http://www.badger5.demon.co.uk/bin/conversion-calcs-web.xls
regards
Bill
mark sheerin
23-11-2002, 18:22
Originally posted by chriskaven
I have a converter program at work which converts loads of different units Power, , pressure, weight, torque, speed etc etc. It is only a small .exe file. Who should i send it to to get it on the site??
Email it to ZBoyd or Shaggy
Zip it if its quite big.
If its useful they'll add a link from the main seatcupra.net homepage
Mark:cheers:
Dormouse
23-11-2002, 19:54
Chris,
Send it to Z, as lee's still got his dodgy back.
can you send me a copy too?
Thanks
Dor.