tuning help (using logger)

[siceclipse]

hey guys i have a question about tuning for ya.
FPBigT-28, ported everything, 2.5 mandrel turbo back, all fuel mods, 560cc and SAFC.
I DON'T HAVE A FMIC YET!

so heres the deal. I installed a test pipe about 2 months ago, and went out and did a run. i noticed that my rear O2 readings went from .92-.94 down to .84-.80 since the pipe was installed.

My timing was way low also. 7* at 3200RPM and climbes to 12* at 6000RPM

I was scared that i was running super lean from the O2 reading, as well as the low timing advance, so i searched.

After reading the the threads that turned up in my searches, i found that the O2 is not that reliable and i should tune for timing with the datalogger instead. So i did what anyone would do and added fuel in the upper RPM range to see what effects it might have.

AFTER EFFECT:
I decided to make my 4K-7K RPM High points -25% from the -35% they were on the first run.

My timing started to advance up a couple of degrees but still is peaking at 16* at 6700RPM.
not bad but could be better.

My main problem is with the O2 readings. they stayed the same for the most part but were reading in the high 70's in the lower RPMs and then going to .80-.84.

should i be concerned about the low O2 readings?????

Thank you!

 

[CanadianTSi]

Pay no attention to the rear o2 readings.

Some people such as myself use the front o2 readings just for reference.

Just tune for a smooth timing increase. 16 is factory spec but with the S-AFC you should be able to see 18-19.

 

[siceclipse]

if nobody has anything else to add or contest, im good to go.

like i said the #'s were worrieing me a little since everyone is about "you want to see .92v!"

ill tune for timing and add or subtract fuel here and there looking to start a 7*-9* and peak at 18-19 by 6500RPM.

thanks!

 

[94Jettameowpsst]

As everyone else said watch your timing.....almost makes me glad i have a knock sensor cause i see upwards of 29*

 

[siceclipse]

Done and done!


Thanks guys.

 

[scottsee]

Tuning is so lucritive. All that matters is what Airflow and Timing map your running in. For the sake of being lazy, here.

http://www.racingknowledge.org/topic.asp?TOPIC_ID=1011

 

[siceclipse]

Thanks a lot! I forgot about that site!