2G How does this log look?

[Cool Mr Steve]

Time, RPM, Timing, O2
00:04.42, 2740.0, 16.0, 0.9,0.0
00:04.73, 2844.0, 16.0, 0.9,0.0
00:05.05, 2948.0, 13.0, 0.9,0.0
00:05.36, 3076.0, 10.0, 0.92,0.0
00:05.67, 3200.0, 8.0,0 .94,0.0
00:06.00, 3336.0, 4.0,0 .94,0.0
00:06.32, 3512.0, 4.0,0 .86,0.0
00:06.63, 3656.0, 5.0,0 .94,0.0
00:06.94, 3812.0, 7.0,0 .94,0.0
00:07.26, 4028.0, 8.0,0 .96,0.0
00:07.57, 4208.0, 9.0,0 .96,0.0
00:07.90, 4300.0, 9.0,0 .9,0.0
00:08.22, 4436.0, 8.0,0 .96,0.0
00:08.52, 4608.0, 9.0,0 .96,0.0
00:08.85, 4776.0, 9.0,0 .96,0.0
00:09.15, 4940.0, 10.0, 0.96,0.0
00:09.47, 5112.0, 10.0, 0.96,0.0
00:09.79, 5280.0, 11.0, 0.96,0.0
00:10.10, 5408.0, 13.0, 0.98,0.0
00:10.43, 5572.0, 13.0, 0.98,0.0
00:10.75, 5688.0, 14.0, 0.98,0.0
00:11.06, 5852.0, 15.0, 0.98,0.0
00:11.36, 6000.0, 16.0, 0.98,0.0
00:11.68, 6124.0, 16.0, 0.98,0.0
00:12.00, 6240.0, 16.0, 0.98,0.0
00:12.32, 6356.0, 14.0, 1.0,0.0

550's, big 16g, 94 octane, 17.5 psi, -6% up to about 4500, then -9% after that

 

[Pure92TSi]

Looks a little rich to me. Lean it out a small amount and see if it feels better. You don't have anything that shows knock?

 

[Cool Mr Steve]

I have a 2g... It won't show an accurate knock reading. It does look a little rich to me too, what would be a safe increment of fuel to take out? 3%? Should I do it 1% at a time? Should I be aiming for .94 or .92 on my O2?

 

[Quasimondo]

Don't go by the O2 readings, look at your timing advance. By redline, you should be around 18-20*. 2G's usually have a dip in timing at around 3K, but by redline they should be back up. See how the timing stops advancing after 4200? It might be seeing some knock which means it might be leaning out a bit. Try richening it up after 4200.

 

[Staytuned]

You are running really rich, probably bogging down the car. From idle to about 3,500 rpm you want the o2 reading to be around .7. That is going to be around the correct air fuel mixture which is 14-1. This will help with faster spool-up, and it will run better. If you have a knock reader you can even lean it out a little more than that as long as your knock doesn't go up, which will result in more horsepower. Now beyond 3500 rpm you are still too rich. .8 o2 sensor reading should work well because you want to run it a little rich at higher rpm to decrease the chance of detonation.
-Joey

WRONG WRONG WRONG....there is no way in hell you should be telling this guy to tune for .7 or .8 narrow band O2 values. He is running a little rich not fuel pouring out of the tail pipe rich. Take a 2% out from 4000 up and try that. Aim for .94 for now but no lower than .92, that should get you down to 11.5:1 a/f ratio. And watch your timing curve make sure it gradually rises. A one degree dip is not that bad........2 or more and you are knocking substantially.

 

[Cool Mr Steve]

Ok, I have one vote for richening it up after 4200 rpm, and one vote for leaning it out... ... I'm very new to this whole SAFCII tuning thing, and both of your points seem valid, but it seems as though only one method would be correct. So who do I listen to? I won't have any time to tune again until friday or so, so I'm accepting input until then.

 

[Staytuned]

There is no way your too lean at .96v, thats around 10.5:1 A/F ratio. Lean it out 2% like I said. There is only two points on that log that concern me at 3512 rpm point it says you had .86v and at 4300 rpm it says you have .90v. These two areas being such a short time span before your fuel richens up again I doubt you can tune these out.....so I wouldn't worry to much about them. So at 4000 I would take out 1% and at 5000 up I would take out 2% to start.

 

[Quasimondo]

Why are you having this guy try to tune through a narrowband O2 sensor?

 

[Staytuned]

Cause that's all he's got and it beats tuning with nothing at all. And I know a little about wideband and narrowband tuning because I have done both, and I know what works.

 

[Cool Mr Steve]

Keeping in mind I don't want my car to explode, would it be safe for me to try it both ways? Should I do a run after I lean it out a little, then another after richening it up to see which proves to be the best tune? Someone put me at ease and tell me I'm not at a tune where my car could explode... Also, I didn't pull all the way to redline as you can probably see by my log, but when I did hit 6300 it looks as though I got richer and my timing dropped by two degrees. Does that mean anything? Does it mean that I'm too rich, at least at that point?

 

[GSXTuner]

00:07.26, 4028.0, 8.0,0 .96,0.0
00:07.57, 4208.0, 9.0,0 .96,0.0
00:07.90, 4300.0, 9.0,0 .9,0.0
00:08.22, 4436.0, 8.0,0 .96,0.0

this is the one part that looks a little odd to me.. your 02 drops quite a bit at 4300.. if you lean out much before 4300 it may cause that spot to get way too lean..?? like stay tuned said.. lean out 1% from 4-5k, then try a little more to drop your o2's to around .93ish .. .

btw i have that same timing dip as you do from 3xxx-4xxx

 

[Quasimondo]

Cause that's all he's got and it beats tuning with nothing at all. And I know a little about wideband and narrowband tuning because I have done both, and I know what works.

Then you should know that tuning via narrowband is tuning with nothing at all. You can't tell what the air/fuel ratio is outside of 14.7:1 because that's all it's calibrated to look for. It's not going to know if your air/fuel ratio is 10.5:1 or 11.5:1 or whatever because all it sees is an mixture that is richer than stoichiometric (14.7:1). You're not going to tune an engine to run at that ratio at WOT, so why try to guesstimate what the air/fuel ratio is with a device that is not calibrated for that function?

 

[Staytuned]

Then you should know that tuning via narrowband is tuning with nothing at all. You can't tell what the air/fuel ratio is outside of 14.7:1 because that's all it's calibrated to look for. It's not going to know if your air/fuel ratio is 10.5:1 or 11.5:1 or whatever because all it sees is an mixture that is richer than stoichiometric (14.7:1). You're not going to tune an engine to run at that ratio at WOT, so why try to guesstimate what the air/fuel ratio is with a device that is not calibrated for that function?

Again, I am not guessing I have logged both narrow and wideband values on my old palm setup. I am not going into details how I did this, but I have seen proof that wideband A/F ratios of 11:1 - 11.5:1 fall into the area of .92v on the narrowband O2 sensor. I wouldn't tell him to do this if I thought it wasn't good info.