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New logs,


Proven Member
May 10, 2002
Austin, Arizona
Haha, I put some 100 octane in my car yesterday, and holy nutts can you run a lot of boost like that. heres some logs, first one was at 15 psi, then the second was at 17psi Ill just show the second one

2nd gear:
300rpm...1 knock...20deg... o2 .96

4500rpm...0 knock...18deg....o2 .96

5500rpm...0 knock...23deg... 02 .94

6200 rpm...1 knck...21deg... o2 .94

7000rpm...0 knock...17deg... 02 .94

3rd gear:
5100rpm...0 knck...19deg... o2 .94

5750rpm...0 kncok...22 deg...o2 .94

6100rpm...0 knock...22 deg...o2 .94

6400rpm....0 knock...21deg...o2 .94

6750rpm...0 knock...18deg....o2 .94

6906rpm...0 knock...18deg...o2. 92

I forgot I put in the 100 octane yesterday, and just remembred after I looked at how much timing I was getting. Air temps were 119deg the whole time, nd coolant temp was 199deg solid. Usually when its this warm out, I get much less timing and a tiny bit o knock. Ill have to retune when i put back in the 91 octane:mad: but for now Im going to run it like this while I can. I know I could run a lot more than 17psi right now, as those o2's are pretty rich, egt's were only at 820*.My high fuel trim was at 96%, mid was at 92% and my low was at 134%, could some one explain to me how I can apply the fuel trims for knowledgable or tuning purposes. Thanks


May 16, 2002
Chelmsford, Massachusetts
I am not sure if Pocketlogger can do it, but TMO logger can create jpg files from those logs. Much easier to post logs :)

Anyway, you are way too rich! There is no reason to run that high 02’s if you are not seeing knock. You should be able to lean out your AFC and that should also give you a bit more timing. Or you could have run much more boost like 20-22 psi…



Proven Member
May 10, 2002
Austin, Arizona
Ya I know. Im just taking it easy on my motor till the weekend then Im putting a new one in. I just forgot that I had 100 octane in, I could really car less, cause its gonna need to be retuned when I start using the 91 octane again.


Proven Member
Dec 19, 2001
How is your high setting like on the AFC?

Your low trim seems to be running a little on the lean side. Try adjust your 1k-2k setting richer. Although the ECU has full control if your trims fall within it's *window*, you also want it to fall as close to the middle as possible instead of running on the edge of the window. O2 trim is the short term trim that will affect the long term trims. The conditions that cause the trims to adjust are pretty simple. The info posted by Van:
Low trim - 0-175hz
Mid trim - 175-225hz
High trim - 225 up (before open loop)

The fuel trims will only change in close loop, once you go open, fuel trims dont mean #@%#@%#@%#@% to the ECU anymore. With that in mind, your trims tuning go from idle to 4krpm before it start to go open loop.
It should only be in your Lo setting because you are tuning part throttle/cruising.
Low trim normal adjust itself even at idle. So your affecting rpm range should be 1k-2k range. Mid trim should be around 2k-3k and high 3k-4k before open loop begins. For the obvious reason, the rpm will range depending on which gear you are in so what I stated is just a guide. If you want to adjust high trims, you should hit the highway and maintain throttle position with airflow stated above.
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