I have BE enable set to 90kPa. There are a lot of points from 90 to as far as 135 kPa that still use the PE value instead of the BE value. What is going on here?
It is a 2002 LS1 PCM with 3bar OS.
Not a good thing to be happening...
I have BE enable set to 90kPa. There are a lot of points from 90 to as far as 135 kPa that still use the PE value instead of the BE value. What is going on here?
It is a 2002 LS1 PCM with 3bar OS.
Not a good thing to be happening...
can you post your current file along with a scanner log?
It doesn't have to be perfect, it just needs to be done in two weeks...
A wise man once said "google it"
I went back through and noticed even higher boost values (145 kPa at the PE value instead of the boost value. 8-9 psi and it hasn't kicked over to BE?
Log and file are attached. The word document is all my custom PIDs. You guys REALLY should look into bringing the custom PIDs with the log files. It would make helping other people MUCH easier.
Looks like normal behavior to me, the first cell of the BE table is 105kpa which is when you are hitting BE without issue, just because you set the enable map to 90kpa doesn't mean you can enter BE earlier than the first cell.
It doesn't have to be perfect, it just needs to be done in two weeks...
A wise man once said "google it"
Well, I had asked in the past and you said if I change that to 90 kPa that it will use the value in the 105 kPa slot.
And it is not normal. Having cells in the 135-145 kPa range with the 12.3 PE value is not normal. Look around frame 7425. 7 psi of boost with a commanded of 12.3. Same with frame 7453. etc etc etc
Another suggestion is to make that BE table go lower. Not everyone lives at sea level. 105 kPa is almost 3 psi for me.
Hmmm, not sure, maybe this was one of the cals where the boost table had to be put in a slower response time part of the code.Originally Posted by striker754
It doesn't have to be perfect, it just needs to be done in two weeks...
A wise man once said "google it"
I'm not asking you to change physics. 105 kPa isn't atmospheric pressure everywhere... Look at the BARO. 13.22psi. Thats 91 kPa. Anything above 91 kPa for me is boost.
Last edited by striker754; 06-27-2008 at 11:26 PM.
um, I thought the MAP sensor resets itself at key on so 100ish kPa is no manifold vacuum?
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
I think GM engineers are smarter than that and understand that there is varying atmospheric pressure in the areas where they sell their product.
I have not messed with anything in altitudes over 800 ft so I don't have data to look at. I just thought I remember reading that it checks on start up. The only instance where it would hurt is being high altitude and then driving to lower altitude, but I get what you are saying. I just swore seeing logs of higher altitudes where it was 95-100 kPa at WOT, but I do not have any to look at.
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
It can be anything depending on altitude. Its basic science really, and should have been incorporated into the OS.
below 105 kPa the 105 value will be used.
The BE feature was requested as more of a safety measure, rather than primary tuning method. Most tuners use it that way. It doesn't operate as fast as PE in some cases as it is in a slower executing part of the code.
The LS1 PCM samples the MAP sensor at key on to get a base Baro setting, in NA applications baro can be "sanity checked" at WOT (or high load low RPM) but for FI applications its really, really hard to update Baro wihtout confusing it with boost, so we disable the post key on update in that case.
Hope that helps,
Chris...
I count sheep in hex...
Well no kidding, that is not what I am trying to argue here and there is nothing HPT can do with how GM does the checks. I was just saying that I thought I looked at some high altitude logs where the pressure would be sub 13.5 psia and I saw the MAP closer to 100 kPa at WOT.
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
Thank you.
i had a problem with the 3 bar OS using the PE and not BE over 17psi boost, it is suppose to use the richer of the 2 but in the bug it would go back to the PE once over a certian boost..
the bug was fixed straight away when the guys were told about it,
try re appling your custom OS to your stock tune and go again,
for this reason i always set the PE and BE to the same values, not good when it starts commanding 12.7 at 6000rpm and 20psi boost and takes a few sides off some pistons....
I can't get the BE to work properly in a 2-bar setup on a '99 F-Body (system goes super rich). I saw where others have had the issue in the past (not necessarily on a 2-bar), so I just disabled it completely.
Formerly known as RWTD
Toys: '22 Tesla Model S Plaid / '20 Chevy Duramax / ?20 Sea-Doo RXT-X (2)
James if you are having an issue with a specific OS PLEASE don't hesitate to contact support with the details, we've fixed any that were reported, however if it didn't get reported we cannot fix it.
It doesn't have to be perfect, it just needs to be done in two weeks...
A wise man once said "google it"
this one was a weard one,
it would work perfectly up to around 17psi above that it would switch between PE and BE till about 19psi then it would switch off and run PE all together,
that was a expansive learn with $12k worth of parts destroyed when at 3/4 track it deciedes to swap back to PE...
so im with you now, it is all done with the PE and BE is turned off...
My first 2/3 bar cars were all twin turbos that came up very fast. Once the tune started getting "crisp"the BE was just too slow to respond. The two cars in particular were 99 and 00 C5's. From then on, all of the cars I have tuned run the same numbers in both PE and BE. It's really not a big deal.
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