I'm 99% sure our car doesn't have a baro sensor, and that it just takes a reading from the MAP at key on to get a barometric pressure reading. That said, we have this IPW vs VAC table that has to be using the MAP sensor right? So my thought is if you convert vacuum to absolute pressure (0 vacuum would equal 100 kpa absolute or whatever baro is that day), followed by scaling the absolute pressures to 2.5bar (essentially multiply the absolute pressure by 2.5) doesnt that give us boost proportional fueling? We would have 0-2 fold additioal fuel in boost using a 2.5bar.
I've never been a fan of faking a wider map sensor tune, but this one has me thinking it might be worth it until other solutions are available. Thoughts on how to tune it - adjust the IPW vs VAC table until all in-boost cells in the VE tables are richer than commanded, then dial back the VE tables.
Thoughts? Are people already doing this? Or do i have the completely wrong idea on this table?
I'm using the IPW vs Vac, but GM has it set up backwards. 0kpa in boost, and as the KPA goes up you are in more vac.
FU Tuning
Screaming for Mercy!! wrote:I'm using the IPW vs Vac, but GM has it set up backwards. 0kpa in boost, and as the KPA goes up you are in more vac.
Yep, instead of using the label "manifold absolute pressure" they use "manifold vacuum". So 0kpa on that table with a 1 bar sensor is atmospheric (WOT, 0kpa vacuum). If you're using/faking a 2.5bar map, wouldn't 0kpa on that table correspond to 150kpa boost?/250kpa absolute?
I'm using that with a 1 bar map on a Ecotec with 14 psi.
FU Tuning
oldskool wrote:Screaming for Mercy!! wrote:I'm using the IPW vs Vac, but GM has it set up backwards. 0kpa in boost, and as the KPA goes up you are in more vac.
Yep, instead of using the label "manifold absolute pressure" they use "manifold vacuum". So 0kpa on that table with a 1 bar sensor is atmospheric (WOT, 0kpa vacuum). If you're using/faking a 2.5bar map, wouldn't 0kpa on that table correspond to 150kpa boost?/250kpa absolute?
I've tried to figure out that correlation before while using the 2.5bar GM TMAP with HPT on a J-Body, but never got crafty enough to use all the filtering features and whatnot to create a good histogram. Plus, with it taking over two minutes to reflash the simplist of changes it becomes a test of patience real quick.
FWIW, here are the new row axis values i came up with in absolute pressure using a 2.5bar map:
12.2, 25, 37.5, 50, 62.5, 75, 87.5, 100, 112.5, 125, 137.5, 150, 162.5, 175, 187.5, 200, 212.5, 225, 237.5, 250
Formula used was (100 - [vacuum kpa])x2.5
If our custom OS is not out by october, i intend to test this...
could i see you ipw v vac tables?I am havin nothing but trouble w tuning my car with the fake bar map. i am about to get rid of it but how else would you get enough fuel up top?
2RADCAV Frankie Mikes wrote:could i see you ipw v vac tables?I am havin nothing but trouble w tuning my car with the fake bar map. i am about to get rid of it but how else would you get enough fuel up top?
Hey! It's me - they guys that's trying to help you lol. Did you get the beta yet?
nope. right after i posted that my internet went out. back up again lol.
