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Tuning with 02 voltage on 2G. What voltage anyways?

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DSMJim

20+ Year Contributor
3,328
41
Jul 24, 2002
Just a question about tuning on a 2G with a pocket logger. What would be a suitable range for voltage on the O2 sensor to tune for? Right now I'm seeing .96 at wot but my timing is not coming up that quickly so I need to lean it out. I was wondernig if .90 is better or what have other 2G guys tuned for since we can't see knock?
 
You should tune for whatever O2 voltage gives you the best timing. O2 is not reliable enough to tune with, tune with timing. If you're not getting knock, or not getting much knock, then your O2 is fine, don't worry about it.

2G's usually have a richer signal than 1g's, .90 is probably way lean.
 
Originally posted by kpt4321
You should tune for whatever O2 voltage gives you the best timing. O2 is not reliable enough to tune with, tune with timing. If you're not getting knock, or not getting much knock, then your O2 is fine, don't worry about it.

2G's usually have a richer signal than 1g's, .90 is probably way lean.

Yea. What he said.:thumb:

-M
 
In general .90 volts is too lean on pump. But that only applies to the poor Cali peeps such as myself on our shitty 91 octane. If you're running 93 octane, .90-.91 would probably be just fine at WOT.

As mentioned though...every car..every set up...every o2 sensor...will vary by a little...so take my advice with a grain of salt and just use it as a general guideline.

nineraptor:
.98 volts is insanely dirt piggy rich. Lean it out a bit to around the .93 range during WOT and see if your timing picks up.

-Jon
 
Originally posted by TrustGs-R
In general .90 volts is too lean on pump. But that only applies to the poor Cali peeps such as myself on our shitty 91 octane. If you're running 93 octane, .90-.91 would probably be just fine at WOT.


Jon, you should also state that this reading is a guideline for the 2Gs not the 1Gs (which can be 0.84 and be fine on a cold night).

Rule of thumb: Tune by timing and knock. Not the O2 readings.

-M
 
Originally posted by Phoenyx



Jon, you should also state that this reading is a guideline for the 2Gs not the 1Gs (which can be 0.84 and be fine on a cold night).

Rule of thumb: Tune by timing and knock. Not the O2 readings.

-M

True my guideline is for a 2g. But even on a 1g I don't think I'd recommend going much below .90 volts full boost WOT on pump 91 octane.
.84 on a cold night on 91 octane and you're risking it.

reason being...conditions change.
At the spur of a moment, running on the verge of blowing shit up isn't worth it for your run with a ### civic turbo. *shrug* maybe you're watching your timing at full throttle and 130mph.

I tune for timing, egt, knock and most importantly power....but he asked about 02 voltages and i have no idea if he has access to tune with knock or not.
 
Originally posted by TrustGs-R
nineraptor:
.98 volts is insanely dirt piggy rich. Lean it out a bit to around the .93 range during WOT and see if your timing picks up.

-Jon

that is what i get with it leaned out 10%

14b on a 2g
rewired, steveteked stock pump
450's

Im a little scared to keep going leaner as I am, maybe I can get some 116 at the track tonight.

what range of 02's do you usually see the best timing at on 116 or 112?
 
I haven't run anything above 100 octane yet with this set up. I haven't really been tuning it much, as I'm still waiting for a few more upgrades on their way :) After which I'll have to retune anyway.

on 91 octane and 20psi I'm seeing .92-.93 volts at WOT.
that's my daily driving set up.

100 octane is $4.50/gallon so i've been laying off that addictive crack as of late ;)

i'll hit up the lead after my new fmic comes in. :dsm:
 
I haven't run anything above 100 octane yet with this set up. I haven't really been tuning it much, as I'm still waiting for a few more upgrades on their way :) After which I'll have to retune anyway.

on 91 octane and 20psi I'm seeing .92-.93 volts at WOT.
that's my daily driving set up.

100 octane is $4.50/gallon so i've been laying off that addictive crack as of late ;)

i'll hit up the lead after my new fmic comes in. :dsm:
 
Originally posted by TrustGs-R


True my guideline is for a 2g. But even on a 1g I don't think I'd recommend going much below .90 volts full boost WOT on pump 91 octane.
.84 on a cold night on 91 octane and you're risking it.
[

Hehehe.. well, guess what? I get those readings and I ignore them. If I'm not knocking and timing is high, I'm happy. On a hot day, that O2 reading will go up. If it's colder, well, then you'll have to add more fuel....

There have been times that I've increased fuel significantly and saw no noticeable increase in O2 voltage even though there should've been.

-M
 
OK that gives me some idea. I did a run a few days ago only until 5000rpm just see what the logger would give me. My setup with this run was AFC 550 255lph with re-wire and base fuel pressure set at 43wot (stock) I left my High setting on my AFC at 0 so it was running way rich. The very beginning is where I steped on it which is why timing is so high.

Time RPM Timing TPS O2 #1 O2 #2
2.53 2820.0 27.0 33.79 0.86 0.84
2.99 2914.0 19.0 35.76 0.88 0.88
3.45 3051.0 10.0 67.19 0.92 0.94
3.92 3227.0 7.0 68.37 0.94 0.94
4.37 3398.0 8.0 68.37 0.94 0.94
4.84 3563.0 8.0 68.37 0.94 0.96
5.3 3742.0 9.0 68.37 0.94 0.96
5.99 3926.0 10.0 67.98 0.94 0.96
6.45 4168.0 10.0 67.98 0.96 0.98
6.92 4320.0 10.0 67.98 0.96 0.98
7.37 4477.0 10.0 67.98 0.96 0.98
8.06 4648.0 10.0 67.98 0.96 0.98
8.52 4859.0 11.0 67.98 0.96 0.98
8.98 4996.0 11.0 59.72 0.96 0.98

I just steped on it until 5000rpm just for a quick log (cause it was starting to rain so I didn't have a chance to do much more) and this is what I got. My timing hit 11.00 but was climing so may go up farther.

However my question is why does my TPS only say 67.98 instead of 100% when I was wide open throttle? And which O2 sensor do I tune by the first or second? Which one is first and second on the car is first before the cat and second after? So my second O2 is seeing a richer signal than the first?
 
you tune with the primary o2. #1.
This is the o2 sensor on your o2 housing (if you still have one).

looks like you need to adjust your tps.
 
Also check your throttle cable. 2G's have a habit of getting sloppy after a while. Use the bump stop on the throttle body as your guide. It should barely touch at WOT. When that's all set, use the datalogger to get the TPS to register 100% at WOT.

Matt.
 
I've always heard to tune to .92V, but I would go more towards knock than anything else. I would personally keep leaning out the car until you see knock.
 
2g's will usually need to run at like .98+ volts to keep from knocking on pump gas. That is normal.
 
Originally posted by kpt4321
2g's will usually need to run at like .98+ volts to keep from knocking on pump gas. That is normal.

You are saying .98volts, and everyone else in this post is saving .92 or .94. There are some conflicting stories here. If you are still getting timing advance at o2 voltages of .94, then you aren't getting knock correct? (since 2g's can't log knock?)

I would also say .98+ o2 voltages on a 2g is pig rich.
 
If I go anything less than .98, I see my timing start to advance, then drop by about 3, advance some more, drop by 3, etc. I take that as knock.
 
eh makes since to me.. think about it 2G's have higher compression pistons than the 1G's so it makes perfect since they will incounter knock before a 1G would.. although some good race gas would probly cure that..
 
Originally posted by kpt4321
2g's will usually need to run at like .98+ volts to keep from knocking on pump gas. That is normal.



Not from my experience. My 02s have been as low as .88v(which when looked at on a wideband, was 12.3:1 A/F ratio. ON 93 octain, I was getting 19-20 degs timing all the way to redline.
 
Originally posted by GSX4LIFE




Not from my experience. My 02s have been as low as .88v(which when looked at on a wideband, was 12.3:1 A/F ratio. ON 93 octain, I was getting 19-20 degs timing all the way to redline.

Would this kind of timing advance be possible on a more 'stock' setup? I am currently tuning the car to run with 15-16 degrees of timing at redline at WOT @ 15PSI on 94 octane. I'm trying NOT to tune with my O2, as it kinda varies and doesn't seem to be a reliable method. I thought this is what everyone else was tuning to as well. Should I be looking for more timing, or is this just not possible without a wideband and fuel tuning device? I've never seen this much timing on a 2G before.

Thanks in advance,
Matt.
 
Originally posted by GSX4LIFE

Not from my experience. My 02s have been as low as .88v(which when looked at on a wideband, was 12.3:1 A/F ratio. ON 93 octain, I was getting 19-20 degs timing all the way to redline.

Do you have an egt gauge? I'm just curious what your EGT's were with o2 values of .88v. I would think your egt's would be through the roof. I can not see .88 volts at wot; I start getting worried if I see mine dipping into the .92 range...
 
Just to suppliment this thread incase somebody in the future is searching and needs this info I will post what I posted in a newer thread.

Basically I got it all worked out. I tuned for Timing not O2. When the timing was going along good, the proper O2 showed up. Here is a log from later on. I fixed my TPS problem too...

RPM Timng TPS O2
3148.0 26.0 21.61 0.3
3219.0 11.0 94.3 0.9
3359.0 8.0 95.87 0.94
3508.0 8.0 95.87 0.94
3664.0 8.0 95.87 0.94
3801.0 9.0 95.87 0.94
3945.0 10.0 95.87 0.94
4207.0 10.0 95.87 0.94
4336.0 10.0 95.87 0.96
4473.0 10.0 95.87 0.96
4598.0 10.0 95.87 0.96
4730.0 10.0 95.87 0.94
4855.0 12.0 95.87 0.94
4984.0 12.0 95.87 0.94
5113.0 12.0 95.87 0.94
5238.0 14.0 95.87 0.94
5348.0 16.0 95.87 0.94
5492.0 16.0 95.87 0.94
5586.0 18.0 95.87 0.94
5691.0 18.0 95.87 0.94
5887.0 19.0 95.87 0.94
5984.0 21.0 95.87 0.94
6078.0 21.0 95.87 0.94
6168.0 21.0 95.87 0.94
6254.0 21.0 95.87 0.94
6352.0 23.0 95.87 0.94
6426.0 23.0 95.87 0.94
6512.0 23.0 95.87 0.94
6602.0 23.0 95.87 0.94
6215.0 24.0 60.12 0.96
4859.0 38.0 0.0 0.62

As you can see by 6600 rpm i was getting 23 deg of timing which is a lot however this will be pushed down to 20 or so when my 50 trim goes on. As you can see when I got the timing to raise in a nice smooth fashion .94 showed up. THis number is sometimes .92 at night now and .96 during the day so I dont really rely on this however when the timng curve is nice then you know all is happy.
 
Jim,

My logs from this week are almost exactly the same as yours, with the exception that my O2's were between .96 and .98 by 7,000 RPM. That and the fact that my advance stopped at 18 degrees at 6,000 RPM and held until redline. It never reached the magic 20+ numbers that you are seeing. I did the same as you did and tuned for timing, not O2. As you stated, when timing was in check, the O2 followed. One question I have, though... Why is the timing in the lower RPM ranges so low? I found the same numbers as you have posted and assumed that I was getting phantom knock. Is this normal? Wouldn't it make more sense for the computer to advance timing in the lower RPM's to increase mid-range torque?

Thanks,
Matt.
 
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