Manifold absolute pressure

Bouncerbeater

Old enough to know better
Mar 15, 2013
1,303
1
Gloucestershire
Can anyone confirm the formula for working out boost pressure from map figures in kpa ?
Been looking through some logs and it seems my boost is spiking to 31psi ish according to my calculations which seems very high but then I may be working it out incorrectly. Any ideas ?
 

Bouncerbeater

Old enough to know better
Mar 15, 2013
1,303
1
Gloucestershire
Some basic logs below where the map reading is even higher. Excuse clumsiness as I was doing it on iPad.
b7b589d2080b8fdab22f82b8f1d26464.jpg



Sent from my iPad using Tapatalk
 

Hobbiniho

Active Member
Jan 17, 2009
545
9
shetland/ Aberdeen
are you remembering to take off atmospheric pressure which is 1.013barg?? as most/all boost gauges show gauge pressure i.e pressure above atmospheric so 1 bar on your boost gauge is actually 2.013bar absolute

edited to add 1bar=13.5psi
 
Last edited:

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
31,333
19
glos.uk
This is why I was concerned, it's amk
At yours in the morning for a smoke test Bill.
These kpa readings are calculated if I rember correctly, maybe not accurately ?

they cant be real.. Factorys map sensor can only read 2550mb measured. (255kpa) aka 1.5bar boost etc etc

some calc gone awry me thinks

what software logging was this done on?
 

Bouncerbeater

Old enough to know better
Mar 15, 2013
1,303
1
Gloucestershire
they cant be real.. Factorys map sensor can only read 2550mb measured. (255kpa) aka 1.5bar boost etc etc

some calc gone awry me thinks

what software logging was this done on?

Is an obd app on iPhone/iPad
My lead has turned up today for vagcom so will hopefully get some better logs to view