Printable View
Thanks Joecar. I see the option to select the different units now, but I'm still getting wacked out values in the scantool map.
For the "VE" map there are values between 1.21-1.47 in the lower rows. When the same values are displayed in % they range between 44-62%. Maybe I'm missing something; but that's a huge difference.
Hey DrkPhx:
Probably need to see that log if you have time.
Generally (depending on displacement) a '100'% VE' equates to ~ 2.49 g*k/kPa. Of course that depends on DYNAIRTMP, air density, etc..
It is confusing. There is a CALC.VE and a CALC.VE Table. And you have to make sure displacement is being properly calculated.
If it makes you feel any better..once you get it..it is never hard again!
If you have successfully logged all the PIDS, Joecar or I can double-check your CALC.VE Table %'s on this end.
I'm definitely logging the Calc.VE_Table pid. I don't have the Calc.VE pid selected.
I just looked at my pids and didn't even realize GM.DYNAIRTMP.DMA is coming up invalid and not logging. I have it set to C.
That's what's causing the VE values to be wrong...Quote:
Originally Posted by DrkPhx
Which year/model and OS id do you have... (the latest V7.5 software has an update for '97/'98 OS 19980200)... Edit: I am mistaken, I confused this with something else, sorry.
if your OS doesn't have DYNAIRTMP_DMA, then you can approximate it using 0.85*ECT+0.15*IAT or by looking up the temperature blend table.
Joe, what's the basis for this estimator?Quote:
Originally Posted by joecar
It's 98 OS 19980100.Quote:
Originally Posted by joecar
How close is that formula to the pid? Can someone do a quick comparison between the two and see how close the net values are?Quote:
if your OS doesn't have DYNAIRTMP_DMA, then you can approximate it using 0.85*ECT+0.15*IAT or by looking up the temperature blend table
Where did you find that ? I just checked OS 19980400 (that's the one I asked for) and a quick check of OS 19980200 and they are both X out as not valid. Is there something else I need to look at? Do I need to re-validate PIDs?Quote:
Originally Posted by joecar
Thanks.
Hey Guys & Gals:
Its possible Joe may have went to church or slept in. I am sure he can explain the 'estimator'. It merely an attempt to approximate the 'charge temperature blending' (B4901)..though it varies a lot by OS and year.
The Look-Up Table 'works', but has a problem with Low Airflow (< 10 g/s) in interpolating.
The difference between CALC.VE Table (with DYNAIRTMP) and the the older CALC.VE (No DYNAIRTMP) is ~ 3-9 %. CALC.VE Table will be greater and is highly advised to use (and also very accurate..I.E. MAF Failure verified..) I am sure Joecar can track down the status of the DYNAIRTMP PID..
Attachments Follow..
Sometimes PIDs are invalid until you start logging or monitoring.Quote:
Originally Posted by Ninety8C5
Select them anyways and start logging/monitoring to see if they become valid.
Of course calc_pids need their dependent PIDs selected to be available.
Quote:
Originally Posted by joecar
Quote:
Originally Posted by redhardsupra
It was late last night when I typed that... :doh2::doh2::doh2::doh2: <- me slapping upside my head 4xQuote:
Originally Posted by DrkPhx
Sorry, I had meant to type this: 0.85*IAT+0.15*ECT
i.e. it should biased toward IAT.
I intended that as a simple estimation, exactly what Shawn guessed I was doing...
I say this from looking at B4901 and from observing DYNAIRTMP_DMA say when VSS > 30 mph in various logs...
I should have instead said to study B4901 for your airflow range, which brings us to the next point:
A more accurate way to do this is to do a lookup of the B4901 values as suggested by mr.prick earlier in this thread...
and this is exactly what Ninety8C5 did: showpost.php?p=118165&postcount=29
[ but this still doesn't factor in B4902 ]
:)