Adding headers + O2

[BRD-PREY]

What do most of you do?
Install the wideband in the one bung and then use the 0 to 1volt output as a substitute for the factory o2 and 0 to 5 for tuner? Or do you just weld in a second bung and not bother with the 0 to 1 out?
thanks Ed
If you install a second bung and suggestions on where? I have QTP LT and Y-pipe for an 01 ws6

[mr.prick]

I welded the bung in the catback just under the passenger rear seat.
This way the exhaust from both banks flow past it,
I didn't like the wild fluctuation in AFR I got from having it in one side of the exhaust.

[tokymon]

that really depends on the wide band. I installed a second bung because i have a lm-1 and use it on several vechiles as it will log afr in it self.
Would to the same if you have lm-1 or lm-2.
guage type wide band or race car yes permant is stall is best
but really it's you choice

[BRD-PREY]

It will definitely be permanent. I have an LC-1 but I was thinking why not use the 0-1 vdc out of the LC-1 for the PCM and 0-5 vdc for the wideband. That would mean I could use the 2 existing bungs in my collectors and not have to weld a new bung on.
Ed

[waterbug1999]

I have mine on the passenger side "Y" pipe at 3 o'clock about 3" after the header..

I would have done it where Mr.Prick is talking about but I have duel cut outs, which are not completely air tight and would cause bad readings.

[BRD-PREY]

does anyone use the wideband to also feed the PCM?

[tokymon]

ya theres other that use lc-1 as the narrow band to if i rember correctly you use both the wires from the analog out put 0-1 volt and i would sugest you log serial into youre v2

[mr.prick]

does anyone use the wideband to also feed the PCM?

I'm sure some people use the simulated signal for NBO2 but
is it going to be a good match for GM O2 sensors?
The LC-1 manual says that analog #1 is pre-programmed for this
1.099 volts = 14.08 AFR / 0.958 LAMBDA
0.103 volts = 15.01 AFR / 1.021 LAMBDA

If you do this and difference between bank1 and bank2 LTFT is more than 2%,
then it's probably not a good idea.

[BRD-PREY]

My initial thoughts were to get a second LC1 and have a wideband in each header. This would then allow me to wire up both sensors to the PCM as well.

Probably overkill but I too have a cutout thats not air tight and I was also thinking that the closer to the cylinder the O2 is the less delay between whats read and actual, which would be more accurate on transitional throttle readings? right?
Ed

[mr.prick]

I doubt it's much more,
even the "slower" WBO2 controllers signal is pretty fast.
There will always be some lag, MAP will change quicker than exhaust will flow.
I can deal with a little lag but I couldn't stand the wild fluctuation I got from
having my WBO2 in one bank.
This was probably due to the cam.

[dfe1]

One of the problems I see with using NB signals off a wide band is that you don't have a reference or back-up. If your wide band starts acting flaky, and you also have a narrow band in place, you have a bit of a reference as to whether the problem is the sensor, or something else. As an example, I have an LM-1 that's several years old, and I was convinced it had gone bad because it was showing an excessively lean condition. The car ran fine and didn't feel lean, but when I looked at the narrow band readings and found they also showed lean, it was apparent that the wide band was operating properly. Richening the mixture changed readings on both the wide band and the narrow bands, so everything is apparently right with the world, except for the idiots in Washington.

[mr.prick]

everything is apparently right with the world, except for the idiots in Washington.

http://smiliesftw.com/x/madwerd.gif (http://smiliesftw.com)

[tokymon]

lol Ottawa is no better
can you program the lc-1 like the lm-1 to change the output voltage this would help simulate the narrow band

[nathans1987]

if you put widband after cats does it effect the reading?

[dfe1]

if you put widband after cats does it effect the reading?
Definitely. Part of what a converter does is use oxygen in the exhaust to oxidize HC and CO into CO2 and water vapor. There's also a reduction process that separates NOx into nitrogen and oxygen, but the net result of both processes is a relatively low oxygen level on the outlet side of the converter. At wide open throttle, I've found that pre-cat and post-cat O2 levels are only off by .1 AFR (as an example 12.9:1 pre-cat, 13.0:1 post cat). I did that testing with two LM-1s connected. At idle and cruise, the pre-cat/post-cat O2 levels vary considerably more because the exhaust has a longer dwell time in the converter.

[mr.prick]

At wide open throttle, I've found that pre-cat and post-cat O2 levels are only off by .1 AFR (as an example 12.9:1 pre-cat, 13.0:1 post cat). I did that testing with two LM-1s connected. At idle and cruise, the pre-cat/post-cat O2 levels vary considerably more because the exhaust has a longer dwell time in the converter.

Interesting, WOT will be close but LTFT areas will be off. :secret: