Power FC UEGO Linear O2 Test 2
12-17-01 | 11:03 AM
#1
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Eye In The Sky
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From: In A Disfunctional World
UEGO Linear O2 Test 2
Recap from test 1 as previously posted.
At 12PSI boost I was running in the 12.1 to 11.8 AFR range off the injector fuel map only. I was wanting to run in the 11.8 to 11.5 range.
Test 2.
On the PIM Voltage map, I added 3.9% fuel at 4.5V and 4.0V. This corresponds to 14.3PSI and 10.5PSI.
This has resulted in what I wanted. My AFR range is now 11.7 to 11.4. This is how I figured to use about 4%.
12.1 / 11.8 = 1.025
1.025 * 1.39 (a fuel cell at 4800rpm in row 17) = 1.425
1.425 - 1.39 = .035, so I added 3.9%.
Next I ran a 14-14.5 boost run. My AFRs were 11.4 to 11.2, a richer and cooler mixture but not over rich.
Next I ran the lowest boost posible. Due to the fact that my ported WG is still inadeqaute to keep boost lower then 11PSI when the turbos are fully wound up, the boost started at 7PSI but by 6500RPM went up to 11PSI. My AFRs were in the high 13s to medium 12s in the lower boost range. I have since also added 3.9% at PIM voltage 3.5 which is 6.5PSI. Still have to test this.
A note, at 12 and 14PSI boost run with non-seq, the AFRs below 4000rpm are in the 14s to 13s and this is with seq fuel maps for that region. The above 3.9% at PIM voltage 3.5 should help that but I am also adding in some fuel for those cells. Hope to run some more tests this weekend.
At 12PSI boost I was running in the 12.1 to 11.8 AFR range off the injector fuel map only. I was wanting to run in the 11.8 to 11.5 range.
Test 2.
On the PIM Voltage map, I added 3.9% fuel at 4.5V and 4.0V. This corresponds to 14.3PSI and 10.5PSI.
This has resulted in what I wanted. My AFR range is now 11.7 to 11.4. This is how I figured to use about 4%.
12.1 / 11.8 = 1.025
1.025 * 1.39 (a fuel cell at 4800rpm in row 17) = 1.425
1.425 - 1.39 = .035, so I added 3.9%.
Next I ran a 14-14.5 boost run. My AFRs were 11.4 to 11.2, a richer and cooler mixture but not over rich.
Next I ran the lowest boost posible. Due to the fact that my ported WG is still inadeqaute to keep boost lower then 11PSI when the turbos are fully wound up, the boost started at 7PSI but by 6500RPM went up to 11PSI. My AFRs were in the high 13s to medium 12s in the lower boost range. I have since also added 3.9% at PIM voltage 3.5 which is 6.5PSI. Still have to test this.
A note, at 12 and 14PSI boost run with non-seq, the AFRs below 4000rpm are in the 14s to 13s and this is with seq fuel maps for that region. The above 3.9% at PIM voltage 3.5 should help that but I am also adding in some fuel for those cells. Hope to run some more tests this weekend.
Last edited by cewrx7r1; 12-17-01 at 11:21 AM.
12-17-01 | 06:02 PM
#3
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Joined: Mar 2001
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From: Austin, TX
Chuck, quick question.
The PIM voltage map you're talking about, this is in the PIM voltage settings, on the screen after the RPM percentage adjustments?
Modifying the percentages on that page will alter fuel according to boost pressure?
How does that interact with the percentage from the previous screem (the RPMs)? Like, if I'm at 4000rpm, and I've got that set at %109, and I'm at 12psi, and that's set for %104, do I get the sum (%113) or the average (%106.5)?
Or does it even work like that (I'm away from the car at the moment, so I can't just go look at the screen to see if I'm just asking a totally wrong set of questions)?
The PIM voltage map you're talking about, this is in the PIM voltage settings, on the screen after the RPM percentage adjustments?
Modifying the percentages on that page will alter fuel according to boost pressure?
How does that interact with the percentage from the previous screem (the RPMs)? Like, if I'm at 4000rpm, and I've got that set at %109, and I'm at 12psi, and that's set for %104, do I get the sum (%113) or the average (%106.5)?
Or does it even work like that (I'm away from the car at the moment, so I can't just go look at the screen to see if I'm just asking a totally wrong set of questions)?
12-17-01 | 10:37 PM
#4
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Eye In The Sky
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From: In A Disfunctional World
GOBLIN,
When you go into the PIM section, the first map is to add extra fuel by RPM. If you add 10% at 5000, it should be inerpolated as 5% at 4500 and 5500 rpms. At 4000 and 6000rpms, it should be 0%. If two adjacent rpm bands are changed, then average them for points inbetween. The same applies to the second PIM screen which is the by map sensor voltage/pressure.
The PFC is all additive with fuel adjustments.
You would add all adjustments together when they occur at the same time. Thus your example would get 113%.
When you go into the PIM section, the first map is to add extra fuel by RPM. If you add 10% at 5000, it should be inerpolated as 5% at 4500 and 5500 rpms. At 4000 and 6000rpms, it should be 0%. If two adjacent rpm bands are changed, then average them for points inbetween. The same applies to the second PIM screen which is the by map sensor voltage/pressure.
The PFC is all additive with fuel adjustments.
You would add all adjustments together when they occur at the same time. Thus your example would get 113%.
12-18-01 | 05:57 PM
#5
Full Member
Joined: Mar 2001
Posts: 184
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From: Austin, TX
Aaaahhh, that'll come in handy, then. Thanks.
So,
4.5 volts is 14.3psi (~1 kg/cm^2)
4.0 is 10.5psi
3.5 is 6.5psi
That looks nicely non-linear. Is the voltage to psi listed in either the PFC or workshop manual somewhere? Or is there a formula for it?
So,
4.5 volts is 14.3psi (~1 kg/cm^2)
4.0 is 10.5psi
3.5 is 6.5psi
That looks nicely non-linear. Is the voltage to psi listed in either the PFC or workshop manual somewhere? Or is there a formula for it?
12-19-01 | 08:50 AM
#6
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Eye In The Sky
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From: In A Disfunctional World
These PIM voltages to PSI conversions are based on MY map sensor output to pressure. This was mention in some other posts, including my test1 and the post about PFC pressure discrepancies.
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