boost pid

[Cablebandit]

how do i get a pid to read boost in psi? I hate converting kpa all the time.
I have a 00 T/A...COS5 with 3 bar.
Any help here?

[vatman02]

i dont think you can unless you have a turbo/blower as oe then you use the gm.boost pid anyone else have any info because i would to know as well

[redhardsupra]

psia=baro+psig right? (psia is the absolute and psig is the 'gauge')
so change units on the existing MAP if you want to read it in absolute.
or if you want the guage pressure, you also have to log baro, and make a custom PID that does psia-baro and does some unit conversion if needed.

[mistermike]

psia=baro+psig right? (psia is the absolute and psig is the 'gauge')
so change units on the existing MAP if you want to read it in absolute.
or if you want the guage pressure, you also have to log baro, and make a custom PID that does psia-baro and does some unit conversion if needed.
I did that a while back. Although it was on a laptop that got stolen, it isn't too hard to re create. MAP - BARO gives you gauge pressure in kPa. Then just do a unit conversion for PSI. You'll get negative numbers under vacuum, but I configured a dashboard gauge to only read from 0 up. It may be better to simply use a fixed average value for BARO, as there's a bug in the ECM that causes it to go to 104 kPa as soon as you go into boost. This error is more than the typical variation in barometric pressure unless you're in the eye of a hurricane.

kPa X 0.14504 = PSI at room temperature

[vatman02]

i'm a little confused (as usual) if take my max kpa 145 multiply by .14504 i get 21.0308 psi so if i subtract my baro 82 kpa 11.89328 psi does that mean my 8# blower is realy putting out 9# of boost does that sound right because my boost gauge only ever sees 6#

[cme265]

i'm a little confused (as usual) if take my max kpa 145 multiply by .14504 i get 21.0308 psi so if i subtract my baro 82 kpa 11.89328 psi does that mean my 8# blower is realy putting out 9# of boost does that sound right because my boost gauge only ever sees 6#
i've had an 8 psi pulley on my procharger for about 2 years now, sometimes i see 6.5 psi(gauge).....other times i see just under 11...depends on what time of the year...stupid atmospheric conditions:nixweiss:

[vatman02]

good to know thanx for the info

[mistermike]

i'm a little confused (as usual) if take my max kpa 145 multiply by .14504 i get 21.0308 psi so if i subtract my baro 82 kpa 11.89328 psi does that mean my 8# blower is realy putting out 9# of boost does that sound right because my boost gauge only ever sees 6#
82 kPa BARO? Wow. Do you carry an oxygen tank around up there?

[vatman02]

82 kPa BARO? Wow. Do you carry an oxygen tank around up there?
no we just make up for it with boost if tuned right you can run stock compression ls1 (10.25:1) at 15# on 91 octane pump gas im at 11.4 with 8# on 91 octane with no kr

[VT LS1 NZ]

how do i get a pid to read boost in psi? I hate converting kpa all the time.
I have a 00 T/A...COS5 with 3 bar.
Any help here?

Here's one you can use ,this pid will only show Gauge pressure(ie no boost will read 0) .I used 102 for baro.



*CLC-00-992
PSI 0.0 20.0 .2 "(({SAE.MAP}>102)*({SAE.MAP}-102))*0.145"

[Earl H]

I use a similar formula however at Idle, my boost guage and boost controller read 13psi vacuum and the pid yields ~ 6 psi of vacuum. Should the formula be adjusted to sync up with the boost guage. Its an autometer guage and Blitz EBC btw.

Formula:

(({SAE.MAP}-102)*0.14503)

[kbracing96]

I use a similar formula however at Idle, my boost guage and boost controller read 13psi vacuum and the pid yields ~ 6 psi of vacuum. Should the formula be adjusted to sync up with the boost guage. Its an autometer guage and Blitz EBC btw.

Formula:

(({SAE.MAP}-102)*0.14503)
Actually, your boost gauge and controller are reading 13 inhg (inches of mercury) of vacuum. PSI= inhg/2 (about)

[Cablebandit]

Here's one you can use ,this pid will only show Gauge pressure(ie no boost will read 0) .I used 102 for baro.



*CLC-00-992
PSI 0.0 20.0 .2 "(({SAE.MAP}>102)*({SAE.MAP}-102))*0.145"



thanks ill try that

[Cablebandit]

works great...thanks though my eboost2 and map sensor read 1 psi diff with the map being the lower of the 2.

[ForcefeedWS6]

Where and how do you go in Efi Live to enter these settings? I would like to make a boost gauge to compare to my autometer boost gauge. Thanks.