2 Bar Stock PCM Speed Density Tune for >6psi (Forced Induction)
03-06-2008, 12:02 PM
#46
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Location: NYC
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two stage boost controller and a window switch ? 
side note: i know nitrous shouldnt be engaged until over 3k rpm since the cyl pressures would get too high etc etc etc. does that still hold true for boost? Im gonna be boosting a stock motor, would it be safer to run it at 5-6 lbs up until say 4500 then let a window switch and two stage controller stab it to 8-9 psi for the 4500-redline?
side note: i know nitrous shouldnt be engaged until over 3k rpm since the cyl pressures would get too high etc etc etc. does that still hold true for boost? Im gonna be boosting a stock motor, would it be safer to run it at 5-6 lbs up until say 4500 then let a window switch and two stage controller stab it to 8-9 psi for the 4500-redline?
Last edited by cause4panic; 03-06-2008 at 12:05 PM.
03-08-2008, 04:18 PM
#50
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Location: North Vancouver, BC
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Are you saying that if the MAP sees 100KPA at key on it will reset below 3700 rpm at WOT anyway? Because we can easily get the Baro to read 100KPA at key on and since it's the highest number maybe it will choose to see that as the max. simply wire in another MAP sensor inline 1 bar map with a switch or relay it at start up so that for a split moment the PCM reads the 1 bar map and than back to 2 bar, you can have it so that as soon as key is on it reads 1 bar map, than when fuel is primed/car turned on, it reads 2 bar map.
03-08-2008, 11:17 PM
#51
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Bunker, yes, Im saying the LT1 pcm resets BARO anytime WOT occurs under 3700rpm. You have a very good point with making key on 100kpa I didnt think about that, but keeping that # will be the tricky part since next time you go WOT under 3700 it will reset - this part is proven in my datalogs... the baro resets each time WOT is seen under 3700..
for example:
1) If you start car and drive normal the Baro = ~51kpa
2) If you rev to 2000rpm then floor it and hold to redline then baro climbs as the MAP climbs to about 3700rpm then the BARO holds the MAP value (which I think is around 62kpa)... and the MAP value keeps climbing to about ~75
3) Once you let off and drive normal again you see the BARO still at 62kpa under the same driving conditions as it just was before the WOT run of ~51kpa.
4) If you enter WOT again at 2000rpm then you see the BARO resets and starts climbing again with MAP to 3700 then holds... same as the run before it.
What I want to see is what happens if you start the car then rev lightly to 4000rpm, then enter WOT for the first time... will the BARO stay at ~52kpa? I think it will this will be my only concern with the 2bar tune... how this affects fueling.. .if it's not that big of change then I can simply tune for it.. but if you run 15psi then it might have a large affect on fueling.
Most other GM PCM's at least older than the LT1 simply log the BARO at key on and that's it... resetting the BARO under 3700 and WOT makes sense simply because you wont have much if any "vacuum" in the intake so it's a good time to get an atmospheric pressure reading for those who are regularly entering WOT/PE. Once you pass 3700rpm you have potential to build manifold vacuum and makes sense why the BARO reset would be limited to 3700rpm. Good for them.. not for us... Im sure LT1_Edit or Tunercats could easily enable changes to this parameter but im sure they never thought to invest the time... I would pay pretty good change for this one single option (disable BARO reset), and pay even more for full 2 bar support (obviosly not as easy to enable). I am sending an email to each company right now... at least possibility to disable BARO reset... I suggest anyone reading this do the same... if they get requests from a few people they might actually look into it.
for example:
1) If you start car and drive normal the Baro = ~51kpa
2) If you rev to 2000rpm then floor it and hold to redline then baro climbs as the MAP climbs to about 3700rpm then the BARO holds the MAP value (which I think is around 62kpa)... and the MAP value keeps climbing to about ~75
3) Once you let off and drive normal again you see the BARO still at 62kpa under the same driving conditions as it just was before the WOT run of ~51kpa.
4) If you enter WOT again at 2000rpm then you see the BARO resets and starts climbing again with MAP to 3700 then holds... same as the run before it.
What I want to see is what happens if you start the car then rev lightly to 4000rpm, then enter WOT for the first time... will the BARO stay at ~52kpa? I think it will this will be my only concern with the 2bar tune... how this affects fueling.. .if it's not that big of change then I can simply tune for it.. but if you run 15psi then it might have a large affect on fueling.
Most other GM PCM's at least older than the LT1 simply log the BARO at key on and that's it... resetting the BARO under 3700 and WOT makes sense simply because you wont have much if any "vacuum" in the intake so it's a good time to get an atmospheric pressure reading for those who are regularly entering WOT/PE. Once you pass 3700rpm you have potential to build manifold vacuum and makes sense why the BARO reset would be limited to 3700rpm. Good for them.. not for us... Im sure LT1_Edit or Tunercats could easily enable changes to this parameter but im sure they never thought to invest the time... I would pay pretty good change for this one single option (disable BARO reset), and pay even more for full 2 bar support (obviosly not as easy to enable). I am sending an email to each company right now... at least possibility to disable BARO reset... I suggest anyone reading this do the same... if they get requests from a few people they might actually look into it.
Last edited by dookie454; 03-08-2008 at 11:27 PM.
03-09-2008, 11:25 AM
#52
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Location: Alta Loma, CA
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... Im sure LT1_Edit or Tunercats could easily enable changes to this parameter but im sure they never thought to invest the time... I would pay pretty good change for this one single option (disable BARO reset), and pay even more for full 2 bar support (obviosly not as easy to enable). I am sending an email to each company right now... at least possibility to disable BARO reset... I suggest anyone reading this do the same... if they get requests from a few people they might actually look into it.
03-10-2008, 11:55 AM
#53
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Location: North Vancouver, BC
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Thanks for the info, with 15lb of boost it may also help though since by 3700rpm the boost will may be very close to 15psi though 
dunno exactly haven't floored it like that yet. However, with regards to having the option with Tunercar, I can tell you right now that LT1_Edit will probably not release anything, but Tunercat will, my friend has sent them many things in the past and they worked with him to put a lot of the features on. One feature is the Closed Loop Timer control recently added by Tunercat, that was a request, he sent them two files, one where he noticed closed loop happened earlier and the other later, and within a few days they sent him a definition file
So I'll send them an email aswell, they may be able to find it and give it to us as Tunercat still constantly updates their definition files for tunercat.
dunno exactly haven't floored it like that yet. However, with regards to having the option with Tunercar, I can tell you right now that LT1_Edit will probably not release anything, but Tunercat will, my friend has sent them many things in the past and they worked with him to put a lot of the features on. One feature is the Closed Loop Timer control recently added by Tunercat, that was a request, he sent them two files, one where he noticed closed loop happened earlier and the other later, and within a few days they sent him a definition file So I'll send them an email aswell, they may be able to find it and give it to us as Tunercat still constantly updates their definition files for tunercat.
03-10-2008, 06:48 PM
#55
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Join Date: Aug 2007
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IT WORKS!! BARO resetting is stopped. LT1_Edit did it for me as a test, then TunerCat investigated it and sent me a new definition file. LT1 Edit also changed the Throttle threshhold to 100% whereas Tunercat is only adding the RPM threshold...
"Hi Dan,
Thank you for your e-mail. We've added the 'Baro Update RPM Threshold' constant to the $EE ECM Definition File. I took a quick look at the code for the $EE and it appears that if the RPM is greater than the RPM value specified by this parameter the baro update is skipped so this parameter to 0 to should disable the baro update at WOT."
I tested it and it works... the one thing this means is fueling has to be increased ALOT... Im getting some knock from it due to leanness but I've been increasing the VE and the PEvsRPM some and it's getting better. It's very worth it because this means consistency each time. With baro reset enabled you could possibly blow up your motor under the worse case imaginable.
A major step forward here!! This should be 100% reliable now.
One other thing Im talking to LT1 Edit is something about re-scaling the MAP tables so 100kpa = 100kpa using a 2bar tune... not sure exactly what he meant but sounded like a partial 2-bar support.. anything helps!
"Hi Dan,
Thank you for your e-mail. We've added the 'Baro Update RPM Threshold' constant to the $EE ECM Definition File. I took a quick look at the code for the $EE and it appears that if the RPM is greater than the RPM value specified by this parameter the baro update is skipped so this parameter to 0 to should disable the baro update at WOT."
I tested it and it works... the one thing this means is fueling has to be increased ALOT... Im getting some knock from it due to leanness but I've been increasing the VE and the PEvsRPM some and it's getting better. It's very worth it because this means consistency each time. With baro reset enabled you could possibly blow up your motor under the worse case imaginable.
A major step forward here!! This should be 100% reliable now.
One other thing Im talking to LT1 Edit is something about re-scaling the MAP tables so 100kpa = 100kpa using a 2bar tune... not sure exactly what he meant but sounded like a partial 2-bar support.. anything helps!
Last edited by dookie454; 03-10-2008 at 06:55 PM.
03-10-2008, 10:14 PM
#57
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Location: North Vancouver, BC
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Yup I also got the email just today with the updated EE, told ya Tunercat will come through right away
So now we just set it to 0 and way we go Sooo happy.
So now we just set it to 0 and way we go
Sooo happy.
Last edited by bunker; 03-10-2008 at 10:26 PM.
03-11-2008, 06:16 AM
#59
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Yea this is good news! The BARO reset has been the only problem all this time.
In related news, I decided to lower my injector flow rating even more (27lb/hr from 30lb/hr) to help richen up boosted fuel since I'm getting near 100% in the VE's... (~84% in the ~75kpa load range or ~7psi).. Did this to give me some room when I go to 15psi. I only have about "2" in the PE vs RPM as well. THis seems to work good but I wont have real results until I get my Wideband sensor working again (timing error).
In related news, I decided to lower my injector flow rating even more (27lb/hr from 30lb/hr) to help richen up boosted fuel since I'm getting near 100% in the VE's... (~84% in the ~75kpa load range or ~7psi).. Did this to give me some room when I go to 15psi. I only have about "2" in the PE vs RPM as well. THis seems to work good but I wont have real results until I get my Wideband sensor working again (timing error).