First track run AFR good, others lean!!
Thread Starter
Supreme Member
Joined: Feb 2002
Posts: 1,036
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From: Prince Albert, Saskatchewan, Canada
Car: 1987 Trans Am GTA
Engine: 357ci Stealth Ram - Under Pressure
Transmission: Built 700r4/Pro Yank 3400 Extreme
Axle/Gears: 9-Bolt 3.27
First track run AFR good, others lean!!
730' ECM.
Went to the track on friday. Having some issues and I have a few questions.
I tuned the AFR with my wideband.
It was OK on the first run then went lean on the others.... I'm not sure if this is tuning related or not? I am running a modified S_aujp bin so BLM's before going into PE won't have an effect.
Why does the AFR vary so much within each RPM tuning range? (3600-4000-4400-4800-5200-5600-6000)
Also - What should WOT KPA be? I'm pulling anywhere from 90.0-93.0kpa at WOT.
Any help would be great.
Thanks.
Run 1: Engine Temp: 93.5*C Air Intake Temp, Start: 66.5*c Finish: 62.7*c
Run 2: Engine Temp: 95.8*C Air Intake Temp, Start: 69.4*c Finish: 65.5*c
Run 3: Engine Temp: 95.8*C Air Intake Temp, Start: 68.9*c Finish: 65.5*c
Run 4: Engine Temp: 97.3*C Air Intake Temp, Start: 74.2*c Finish: 70.0*c
Run 5: Engine Temp: 95.0*C Air Intake Temp, Start: 73.7 Finish: 70.0*c
Went to the track on friday. Having some issues and I have a few questions.
I tuned the AFR with my wideband.
It was OK on the first run then went lean on the others.... I'm not sure if this is tuning related or not? I am running a modified S_aujp bin so BLM's before going into PE won't have an effect.
Why does the AFR vary so much within each RPM tuning range? (3600-4000-4400-4800-5200-5600-6000)
Also - What should WOT KPA be? I'm pulling anywhere from 90.0-93.0kpa at WOT.
Any help would be great.
Thanks.
Run 1: Engine Temp: 93.5*C Air Intake Temp, Start: 66.5*c Finish: 62.7*c
Code:
RPM AFR INJ PW 3870 12.4 9.06 3916 12.6 9.09 4045 13.0 9.13 4096 13.0 9.16 4201 12.6 9.16 4255 12.8 9.19 4349 12.6 9.23 4388 12.4 9.17 4509 12.6 9.16 4593 12.8 9.16 4703 12.4 9.14 4749 12.4 9.14 4795 12.2 9.08 4915 12.4 8.94 5041 12.6 8.97 5120 13.0 8.74 5201 13.0 133.56 5229 12.8 8.52 5371 12.4 8.52 5401 12.6 8.47 5461 13.0 8.21 5617 12.6 8.04 5715 13.0 8.04 5782 13.2 7.95 5921 12.6 8.1 5994 12.4 8.01
Code:
RPM AFR INJ PW 3668 12.8 8.79 3682 13.0 8.94 3766 13.0 8.93 3840 13.0 9.02 3932 13.2 9.06 4012 13.2 9.05 4130 13.0 9.11 4165 13.2 9.11 4274 13.4 9.17 4369 13.2 9.16 4388 13.0 9.09 4509 12.8 9.09 4593 13.0 9.08 4726 13.0 9 4726 12.6 9 4890 13.0 8.9 4915 13.4 8.82 5015 13.4 8.79 5093 13.4 8.68 5173 13.2 8.64 5285 13.2 8.5 5401 13.6 8.29 5461 13.4 8.23 5522 13.4 8.09 5649 13.6 8.03 5748 13.4 8.01 5715 13.8 8.04 6030 13.2 7.95
Code:
RPM AFR INJ PW 3810 12.6 8.94 3870 13.2 9 3964 13.0 9.05 4012 13.0 9.11 4079 13.0 9.05 4130 12.6 9.17 4183 13.4 9.17 4369 13.2 9.23 4448 12.8 9.17 4530 13.0 9.09 4572 13.0 9.09 4681 12.6 9.03 4749 13.0 9.03 4842 12.8 8.97 4915 13.0 8.79 4964 13.6 8.82 5041 13.4 8.68 5146 13.4 8.61 5229 13.6 8.56 5313 13.4 8.42 5371 13.6 8.29 5461 13.6 8.12 5522 13.6 8.04 5585 14.0 7.97 5682 13.8 7.94 5782 13.8 7.94 5816 13.6 8.01 5886 13.6 7.89
Code:
RPM AFR INJ PW 3855 13.4 8.9 3870 13.2 8.88 3916 13.0 8.94 3964 13.2 8.96 4096 13.6 8.99 4219 13.6 9.02 4237 13.0 9.08 4330 13.2 9.08 4509 13.2 9.03 4572 12.8 9.06 4659 13.2 9.06 4703 12.8 8.99 4795 12.8 8.85 4890 13.4 8.85 4990 13.2 8.77 4990 13.2 8.67 5067 13.6 8.59 5229 13.8 8.47 5229 13.0 8.42 5342 13.2 8.15 5401 13.8 8.18 5401 13.8 8.12 5585 13.6 8.04 5851 14.0 7.89
Run 5: Engine Temp: 95.0*C Air Intake Temp, Start: 73.7 Finish: 70.0*c
Code:
RPM AFR INJ PW 3737 12.6 8.82 3795 13.0 8.88 3870 12.8 8.91 3916 13.4 8.94 3996 13.2 8.94 4130 13.4 8.99 4113 13.2 9.05 4292 13.6 9.05 4292 13.6 9.05 4408 13.4 9.03 4468 13.4 9 4509 12.8 8.97 4703 12.6 9 4749 12.8 8.93 4842 13.2 8.81 4890 13.2 8.81 4964 13.2 8.64 5041 13.4 8.56 5146 13.4 8.42 5201 13.6 8.39 5256 13.2 8.32 5491 13.6 8.35 5431 14.0 8.12 5491 13.8 8.04 5491 13.2 7.9 5553 13.4 7.89 5748 13.0 7.89 5748 13.6 7.89 5682 13.6 7.89 5921 13.6 8.47 5715 12.6 7.94 6068 13.0 7.84
Last edited by mike1986fyrbird; May 8, 2007 at 06:36 PM.
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Joined: Sep 2003
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From: Texas
Re: First track run AFR good, others lean!!
Stick the PW next to the above data.
The WOT kpa has to be referenced to the barometric pressure.
More than 4 or so kpa difference from key on/engine off map and you might want to customise your CAI some more.
The WOT kpa has to be referenced to the barometric pressure.
More than 4 or so kpa difference from key on/engine off map and you might want to customise your CAI some more.
Thread Starter
Supreme Member
Joined: Feb 2002
Posts: 1,036
Likes: 0
From: Prince Albert, Saskatchewan, Canada
Car: 1987 Trans Am GTA
Engine: 357ci Stealth Ram - Under Pressure
Transmission: Built 700r4/Pro Yank 3400 Extreme
Axle/Gears: 9-Bolt 3.27
Re: First track run AFR good, others lean!!
I updated the first post and added INJ PW.
I also added air intake temps at the starting and finish line.
Looks like key off MAP KPA is 96.5kpa.
WOT kpa at the start of second is 94.5kpa then decays down to 90.6kpa near 6,000rpm.
Thanks.
I also added air intake temps at the starting and finish line.
Looks like key off MAP KPA is 96.5kpa.
WOT kpa at the start of second is 94.5kpa then decays down to 90.6kpa near 6,000rpm.
Thanks.
Last edited by mike1986fyrbird; May 8, 2007 at 06:36 PM.
Joined: Mar 2000
Posts: 1,692
Likes: 1
From: Corona
Car: 92 Form, 91 Z28, 89 GTA, 86 Z28
Engine: BP383 vortech, BP383, 5.7 TPI, LG4
Transmission: 4L60e, 700R4, 700R4..
Axle/Gears: 3.27, 2.73
Re: First track run AFR good, others lean!!
Heat soak is my guess. On the cars I calibrate, I only follow "speed density" in a narrow range near 10-30 degrees C (IAT). Everything else has a multiplier to cancel the effect of IAT on the FUEL (not GM software, btw). It seems that when IAT is ~40C or above, that it doesn't have any measurable effect on my cars. In other words, if IAT is hot enough, the cylinder charge is basically at coolant temperature. This is using a TMAP sensor which has a birdcage IAT sensor built into a MAP sensor that is directly on the manifold, with the birdcage protruding into the flow.
your results may vary.
You may also have a bit of MAP flutter at WOT (too little filtering), if your A/F is jumping so much. The MAP hose can dampen some flutter. Might also be a problem with your wideband.
your results may vary.
You may also have a bit of MAP flutter at WOT (too little filtering), if your A/F is jumping so much. The MAP hose can dampen some flutter. Might also be a problem with your wideband.
Thread Starter
Supreme Member
Joined: Feb 2002
Posts: 1,036
Likes: 0
From: Prince Albert, Saskatchewan, Canada
Car: 1987 Trans Am GTA
Engine: 357ci Stealth Ram - Under Pressure
Transmission: Built 700r4/Pro Yank 3400 Extreme
Axle/Gears: 9-Bolt 3.27
Re: First track run AFR good, others lean!!
RednGold,
I just went out to see if maybe my input into the ECM for the LC-1 is no fuctioning properly.
I directly inputed the LC-1's serial output into my laptop and the results were quite different. The only problem is that I don't get to see the RPM vs AFR just a graph of the AFR.
I did about 5 runs, each pretty close in AFR and the AFR didnt jump up and down like it does when connected through the ECM. First run started at about 90* and the last nearing 100* or more.
My converter flashes to 3000rpm and I did these runs in second.
At 3000rpm is 13.8:1 and decays down to 13.0 near 4700~rpm then up to 14:1 at the shift point - 5900-6,000rpm.
Looks like i've got some adjusting to do.
Dominic,
I tuned BLM's to around the 124 area. They were below 128 on all runs.
Either way, I am running a modified S_aujp bin so BLM's before going into PE won't have an effect. S_aujp removes adjustments of WOT PW due to high BLM's.
Thanks.
I just went out to see if maybe my input into the ECM for the LC-1 is no fuctioning properly.
I directly inputed the LC-1's serial output into my laptop and the results were quite different. The only problem is that I don't get to see the RPM vs AFR just a graph of the AFR.
I did about 5 runs, each pretty close in AFR and the AFR didnt jump up and down like it does when connected through the ECM. First run started at about 90* and the last nearing 100* or more.
My converter flashes to 3000rpm and I did these runs in second.
At 3000rpm is 13.8:1 and decays down to 13.0 near 4700~rpm then up to 14:1 at the shift point - 5900-6,000rpm.
Looks like i've got some adjusting to do.
Dominic,
I tuned BLM's to around the 124 area. They were below 128 on all runs.
Either way, I am running a modified S_aujp bin so BLM's before going into PE won't have an effect. S_aujp removes adjustments of WOT PW due to high BLM's.
Thanks.
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