Need help tuning MAFT
Thread Starter
Joined: Jan 2002
Posts: 4,069
Likes: 74
From: Casselberry FL
Need help tuning MAFT I monitored LTFTB1/B2, O2B1/B2S1, and Fuel cell for these trips, doing 2nd gear punches from 2K to redline. Base setting is +5, which the lid indicates is "Not used", but +4 is 20% rich. So, calculating based upon TPS=100, and cell=22, and having Fastchips tuning:
WOT 2% lean, 37 samples:
LTFTB1=2.3 in one sample (else 0)
LTFTB2=0.8 in a different sample (else 0)
Avg O2B1S1=.905
Avg O2B2S1=.941
WOT 6% lean, 35 samples:
All LTFT's = 0
Avg O2B1S1=.898
Avg O2B2S1=.952
WOT 10% lean, 42 samples:
All LTFT's = 0
Avg O2B1S1=.891
Avg O2B2S1=.965
At this point my question is, why is one O2 bank going down and the other up?
On the fourth trip, I also monitored STFT's, RPM, MPH, KR, ECT, advance, IAT, and MAF to see if the base needed to be adjusted. More parameters, less samples, and discarding samples with real wide variances between O2 banks:
WOT 14% lean, 16 samples:
Avg LTFTB1 cells 1-19 = -2.5
Avg LTFTB2 cells 1-19 = -4.29
Avg O2B1S1 WOT = .859
Avg O2B2S1 WOT = .934
LTFT's @ WOT = 0
- Should the effect of the WOT POT be linear?
- Is it typical to have the base/wot set like this?
- What causes discrepancy between LTFT banks?
- Suggestions on what I should set it at?
I've got a H/C/I '98 Z28 with Grots as my major mods, and Whisper MAF ends.
Thanks...
Jim
<small>[ March 24, 2002, 05:44 PM: Message edited by: JimMueller ]</small>
WOT 2% lean, 37 samples:
LTFTB1=2.3 in one sample (else 0)
LTFTB2=0.8 in a different sample (else 0)
Avg O2B1S1=.905
Avg O2B2S1=.941
WOT 6% lean, 35 samples:
All LTFT's = 0
Avg O2B1S1=.898
Avg O2B2S1=.952
WOT 10% lean, 42 samples:
All LTFT's = 0
Avg O2B1S1=.891
Avg O2B2S1=.965
At this point my question is, why is one O2 bank going down and the other up?
On the fourth trip, I also monitored STFT's, RPM, MPH, KR, ECT, advance, IAT, and MAF to see if the base needed to be adjusted. More parameters, less samples, and discarding samples with real wide variances between O2 banks:
WOT 14% lean, 16 samples:
Avg LTFTB1 cells 1-19 = -2.5
Avg LTFTB2 cells 1-19 = -4.29
Avg O2B1S1 WOT = .859
Avg O2B2S1 WOT = .934
LTFT's @ WOT = 0
- Should the effect of the WOT POT be linear?
- Is it typical to have the base/wot set like this?
- What causes discrepancy between LTFT banks?
- Suggestions on what I should set it at?
I've got a H/C/I '98 Z28 with Grots as my major mods, and Whisper MAF ends.
Thanks...
Jim
<small>[ March 24, 2002, 05:44 PM: Message edited by: JimMueller ]</small>
Re: Need help tuning MAFT I'm certainly learning as I go here too but one thought I had was that maybe you have a clogged injector or two on Bank 2. If you are leaning it out with the MAFT, both 02 readings should go down somewhat the same.
The right and left sides usually see a bit of FP difference just because without a fuel return line there really isn't a good way for the fuel to stabilize pressure-wise between sides IMHO.
The right and left sides usually see a bit of FP difference just because without a fuel return line there really isn't a good way for the fuel to stabilize pressure-wise between sides IMHO.
