Just wondering what kind of timing advance or retard the pcm will make during boost. Presumably, it's the same as no vacuum?
if you have a 1.0 bar (stock) map sensor it will be the same at pressure as 0psi or atmospheric.
if you ahve an aftermarket 2.0 bar you can do a "fake tune" and pull timing for boost and thats the way to go.
HP Tuners | Garrett T3/T04B | 2.5" Charge Pipes | 2.5" Downpipe | 650 Injectors | HO Manifold | Addco front/rear | Motor Mounts | HKS SSQV | Spec stage 3 | AEM UEGO Wideband | Team Green LSD | FMIC | 2.3 cams | 2.3 oil pump swap | 280WHP | Now ECOTECED
So with the stock 1bar shouldn't it read over 0? or does it read between -14psi and 0psi.
it reads from -25 (ish)mm Hg to 0psi (atmospheric)... on my hptuners it reads from 5-105kpa (105 being atmospheric) the 2.0 bar reads from 0-210kpa(14.7psi), but goes into "over boost" around 199or 200kpa(13.5-13.7psi)...
these both work on a 5v input and 0-5volt output. so you can see the 1.0 bar has twice the "clarity" as the 2.0 bar map.
HP Tuners | Garrett T3/T04B | 2.5" Charge Pipes | 2.5" Downpipe | 650 Injectors | HO Manifold | Addco front/rear | Motor Mounts | HKS SSQV | Spec stage 3 | AEM UEGO Wideband | Team Green LSD | FMIC | 2.3 cams | 2.3 oil pump swap | 280WHP | Now ECOTECED
All non boosted engines read from 0-14.5 psi. 14.5 psi is atmospheric.
Boost is above-atmospheric pressure.
Therefore 1 bar = 0 - 14.5 psi (vaccum... NO BOOST)
2 bar = 0 - 29 psi (14.5 psi of boost)
3 bar = 0-44.5 psi (29 psi of boost)
I hope that makes sense.
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
The problem with faking a 2.5 bar is that you leave yourself with almost no ability to tune out of boost, for a race car this isnt a problem but for a daily driver it makes for a really sloppy tune, even with a fake 2 bar the resolution is considerably less, I doubt that many here run more than 14.7 psi anyway
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
in the near future with a bigger turbo and hptuners i will be planning on running 20psi. but now im not so sure because of the much less resolution there is with a three bar.
DRIVE HARD OR DONT DRIVE AT ALL!!!
Less, much much less
Hahn port fueler is a better option for 15psi + cars
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
From what i am reading, the 1bar sensor stock reads from -14.7 to 0 atmospheric, and nothing more. Hence, the lean spikes in tuning when trying to run boost on a stock pcm with stock 1bar. The question i have is, is there a way to add a 2 bar sensor that will read above 0 atmospheric, and also keep the 1bar in the mix?
Can you daisy chain them, or would it require adding code to read from a separate input and swap between 1bar sensor and 2bar sensor maps when caluclating boost?
with a 1 bar your adding fuel per rpm based on throttle position, map has nothing to do with the fueling on an alpha N car
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
But if you got the s/c reflash then tuned with HPT then your fine right?
