Started to auto tap my car, numbers within

[12secondv6]

Well, auto tap is what I knew to call it but it is really a hand held scanner that can give me some numbers:
OK, at idle
-17-19 degrees timing
Idle 730-750 rpm's
Map sensor 9-10
OK, now these are WOT
Map sensor goes from 10 at idle to 30 WOT
What does that mean?
Timing
WOT low rpm is -21.5 degrees and then as it approaches a shift it is at -25
Again, any feedback?
O2 sensor 1 bank 1 read 895 to 920 millivolts
02 sensor 1 bank 2 read 920 to 940 millivolts
O2 sensor 2 bank 1 read 920 to 930 millivolts
O2 sensor 3 bank 1 read 870 to 885 millivolts

These were wot with me reading them as I was driving so numbers are really close to what I remember
Which is sensor 1, 2 and 3?
Banks 1 and 2?
Are those good numbers?
I have an afpr that I can play with.
I do not know what my current fuel psi is but I will find out tuesday.
I'm looking for some feedback on these numbers if someone could assist me.
I want to go faster and I always guessed with tuning.
Now I wanna tune
Thanks for any help
If you need more numbers I can get them

[Eds02v6]

I'll try to give a little info...Hopefully someone will correct me if I'm wrong...

O2 S1B1 - drivers side sensor in Exhaust Manafold
O2 S2B1 - Passenger side sensor in Exhaust Manafold
O2 S1B2 & S3B1 - before and after Cat O2 sensors

You should really just look at the first two in the ehaust manafolds. For N.A. applications the reading should be somewhere between 0.85 - 0.89 V for optimal tuning, but I remember someone (maybe Magnus) stating that for Nitros that you want O2's in the 0.95 V range. Hope this helps, and good luck tuning!!

[12secondv6]

Well those results were with fuel psi at 28 psi, doh!!!!
I raised the fuel psi to 38 - 39 psi and have more results.
O2 sensor 1 bank 1 read 890 to 900 millivolts
02 sensor 1 bank 2 read 900 to 915 millivolts
O2 sensor 2 bank 1 read 930 to 940 millivolts
O2 sensor 3 bank 1 read 870 millivolts

I plan on lowering the fuel psi 2 psi.
Tuning sucks!!!

Anyone have any input???
I'm really looking for some before my dyno.

[John_D.]

<blockquote>quote:</font><hr>Originally posted by 12secondv6:
...fuel psi at 28... raised the fuel psi to 38 - 39...
O2 sensor 1 bank 1 read 890 to 900 millivolts
02 sensor 1 bank 2 read 900 to 915 millivolts

Anyone have any input??? I'm really looking for some before my dyno.<hr></blockquote>

Interesting that the higher pressure tightened up the numbers on each bank and reduced the variation between the two banks.

On your '97 I believe you should be seeing 40psi stock, at idle. If you have a vacuum port on your fpr, the fuel pressure will vary with different vacuum levels (it should go up when the vacuum goes down). My stock fpr goes to 45-50 under load, and when spraying goes to 55.

Are you looking for the best na or best nitrous dyno results?

For na, you will probably pull hardest if you can average about .87's. For nitrous you will probably want to shoot for the .90-91 range.

Tweaking o2's via fuel pressure will be hard, I think. Especially if you have a vacuum port. Maft will be more precise.

Are you logging the numbers and watching for changes across the rpm band? My car runs a little leaner on top than it does down in the middle (or the sensors are hotter and reading differently...). Logging will more accurately show you if there is a danger zone to tune around, rather than tuning for average readings.

Look at rows where tps is 100%. I think a value of zero in the fuel cell column is also an indication of the pcm going into wot mode. I'd have to look at my old logs to tell for sure. It will be apparent, it's the value that shows up when the tps is 100%... (It also goes into cell zero mode at less than 100% tps, around 85-90% or so on mine.)

[Magnus]

IMHO..

Ditch the adjustable fuel pressure regulator James.. seriousely.

Drop in a walbro 255 and be confident about your fuel supply..

When you play with the fuel PSI, you confuse the PCM. The PCM makes adjustments to the LT's to achieve ITS desired O2's.

With no fuel pressure regulator, and ONLY a walbro 255, I see ~43psi at idle and a SOLID 50psi at wot.. even on the gun.

If you want to change your air/fuel ratio, use the MAF T+ wot settings.. The PCM will learn out your fuel pressure adjustments but it won't learn out WOT adjustments from a MAF T+. ;)

Only o2's you really want to watch are B1S1 and B2S1, those are the ones in the primaries.. For NA records at the track only, try .850 and see how it does (You can easily do this with a MAF T+). For nitrous I'd keep it over .9's to be safe.

[DEE97GTP]

I would also suggest looking at your long term fuel trims. That way you know how much your PCM is correcting.

I personally have been running O2's above .91V, but I am blown. You really need a tool that can log data to really do any useful tuning. Not to mention the danger is going WOT and trying to read a scanner!

DEE

[Magnus]

I agree with Dee..

Also James, your #'s will be more consistant without the AFPR I think.