Speed Density Questions Rom 96531706
#1
Evolved Member
Thread Starter
Speed Density Questions Rom 96531706
Whats up yall.
Been tuning sd for a few weeks and have some questions now.
Got Target WOT afr dialed in.(TUNED IN OPEN LOOP)
Now when I go back to closed loop afr trips out and fuel trims are -12.5.
Also when in forced OPEN LOOP driving around town like a gramma I go rich.
1. How do I cure the rich conditions without affecting WOT afr? So im going rich at cruise 3,000 rpm, So if I lean out rpm ve at 3000 rpm id be affecting WOT targets correct?
2. KPA MAP VE
So ive read a lot on this and everyone keeps saying 0-100 kpa is vaccum but if I google 100 kpa to psi. It is 14.5 psi.
Am I doing the equation wrong?
Also ive read less load on the map ve will remove fuel so for ****s and giggles I set 11.0 kpa to 0 load and had no affect on idle afr. So unsure if its even working.
Been tuning sd for a few weeks and have some questions now.
Got Target WOT afr dialed in.(TUNED IN OPEN LOOP)
Now when I go back to closed loop afr trips out and fuel trims are -12.5.
Also when in forced OPEN LOOP driving around town like a gramma I go rich.
1. How do I cure the rich conditions without affecting WOT afr? So im going rich at cruise 3,000 rpm, So if I lean out rpm ve at 3000 rpm id be affecting WOT targets correct?
2. KPA MAP VE
So ive read a lot on this and everyone keeps saying 0-100 kpa is vaccum but if I google 100 kpa to psi. It is 14.5 psi.
Am I doing the equation wrong?
Also ive read less load on the map ve will remove fuel so for ****s and giggles I set 11.0 kpa to 0 load and had no affect on idle afr. So unsure if its even working.
#3
Evolved Member
Thread Starter
So idk if its the corrct way to do it but i have dialed in wot afr to redline via rpm ve. Map ve has styed close to 1:1.
And brought trims in with latency adjustments.
Idk if its the correct way or not but it worked.
And brought trims in with latency adjustments.
Idk if its the correct way or not but it worked.
#4
Evolved Member
There is no correct way - It is like which way works out for you..
Since i am taking absolute pressure-
0-100 Kpa is vacuum -
above 100 Kpa is positive pressure.
In vacuum you cant stay 1:1 its more like 1:0.7 or 0.8..
I tune more through MAP VE than RPM VE and fine tune AFRs with RPM VE.
200 Kpa + MAP @ 5500 rpm + is WOT now you will have to see where you want to tweak
the map.
i hope this helps.
Since i am taking absolute pressure-
0-100 Kpa is vacuum -
above 100 Kpa is positive pressure.
In vacuum you cant stay 1:1 its more like 1:0.7 or 0.8..
I tune more through MAP VE than RPM VE and fine tune AFRs with RPM VE.
200 Kpa + MAP @ 5500 rpm + is WOT now you will have to see where you want to tweak
the map.
i hope this helps.
#5
Evolved Member
Thread Starter
How do i log kpa?
How come 100 kpa is 14.5 psi when converting?
So is 100 kpa what we live in? Baro? Atmospheric pressure?
And 200 kpa is 30psi but subtract the 14.7 atmoshperic pressure which leaves me at 14.5 psi of boost?
Right or wrong?
How come 100 kpa is 14.5 psi when converting?
So is 100 kpa what we live in? Baro? Atmospheric pressure?
And 200 kpa is 30psi but subtract the 14.7 atmoshperic pressure which leaves me at 14.5 psi of boost?
Right or wrong?
#7
EvoM Community Team Leader
Thats right, KPA is an absolute measurement starting at 0 pressure, like in outer space. We don't live in a vacuum so it starts at what ever the atmospheric pressure is at your location or at sea level its 1 atmosphere = 1 bar = 100kpa = 14.7psi (relative to 0 ). Thats why you need a 3 bar map sensor just to ready up to ~29 psi instead of 44 psi, that first bar gets eaten up by measuring the atmospheric pressure. Also that 1 bar of atmospheric pressure is how N/A engines work.
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4b11slayer (Jul 28, 2017)
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#8
Evolved Member
Thread Starter
#9
Evolved Member
Thread Starter
So my WOT afr seems to be dialed in at 11.8 afr. But cruising around my afr goes 10.8. I noticed its as soon a i start hearing the turbo spool so im assuming as soon as im getting into boost. 0.8-1 psi.
#11
Evolved Member
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4b11slayer (Jul 28, 2017)
#12
Evolved Member
Thats right, KPA is an absolute measurement starting at 0 pressure, like in outer space. We don't live in a vacuum so it starts at what ever the atmospheric pressure is at your location or at sea level its 1 atmosphere = 1 bar = 100kpa = 14.7psi (relative to 0 ). Thats why you need a 3 bar map sensor just to ready up to ~29 psi instead of 44 psi, that first bar gets eaten up by measuring the atmospheric pressure. Also that 1 bar of atmospheric pressure is how N/A s work.
When you tune - you tune both vacuum and positive pressure areas.
According to your MAP VE - 11 to 61 Kpa represents vacuum , you want to adjust the adjacent load column.
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4b11slayer (Jul 28, 2017)
#13
Evolved Member
Thread Starter
Ok so since im going rich at light throttle around 1.0 psi of boost I would remove from the load column in MAP VE around 61 kpa?
Or better yet should I do a log with AFR,KPA,And Omni so I know at what kpa I start going rich then adjust accordingly?
Or better yet should I do a log with AFR,KPA,And Omni so I know at what kpa I start going rich then adjust accordingly?