O2 Voltage bouncing around on LSA

I just added a kenne Bell BAP and larger lower pulley 9.55" up from 9.1" and I am noticing my O2 voltage bouncing around. The scan file I have attached has several 1st, 2nd, 3rd bursts. I am running two cans of Torco in this tank of 92 octane and I'm not sure if this is causing the car to behave so differently. I also changed my PE settings to model another tune that had a BAP installed since I have yet to sort that setting out. I was hoping to get another set of eyes on this. I don't do this enough and this is making me want to start over. Any help is appreciated. Thanks.

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Originally Posted by flavorwrench

I just added a kenne Bell BAP and larger lower pulley 9.55" up from 9.1" and I am noticing my O2 voltage bouncing around. The scan file I have attached has several 1st, 2nd, 3rd bursts. I am running two cans of Torco in this tank of 92 octane and I'm not sure if this is causing the car to behave so differently. I also changed my PE settings to model another tune that had a BAP installed since I have yet to sort that setting out. I was hoping to get another set of eyes on this. I don't do this enough and this is making me want to start over. Any help is appreciated. Thanks.

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Hey I glanced at your log since it's an LSA. BE CAREFUL!! Your config is so different from mine it's hard for me to get a good look at what's happening, but there are a couple red flags for me. One is the 7000rpm I saw, is your engine built as far as pistons, rods and valvetrain? I'd be a little scared running that LSA to 7k, especially with the blower running that fast. Is this car a dedicated track car or is it a daily driver?

Anyway, to your question, the O2 voltages actually aren't "bouncing" enough. The freeway cruise section I looked at showed them stuck at .8xx, and your wideband (which looks slow to me?) was also reading rich at .96 or so. All I can say is there are a few things that don't look right to me. If you want, you can try my LSA config file and see what it looks like with some more/different PID's logged. For instance, you might want to ditch the TPS SAE PID that only reads to 84%. My config has the right TPS PID and also the pedal position, which I believe is vital to see when tuning. Looking at a TPS that only goes to 84% and not knowing what your actual foot is doing in relation to that is like driving with one eye closed. You can do it, but you're not seeing a bunch of stuff!

Here's the link to my config... If you do it, read my directions carefully and change BOTH of the config files I posted in that thread. The only thing you'll have to add in or change is your wideband. Good luck!

http://www.hptuners.com/forum/showth...d-Config-Files

First of all, thank you for taking the time to respond, I really appreciate it.

I remember reading your write up a few weeks ago from work and tried your config file on my work laptop and didn't get much further. I figured if I was going to take the time to set everything back up, I might as well wait and do it once on my Tuning laptop. Great write up by the way.

The config file I used in the above scan was my best attempt at something I could use for my first try at the VVE section of my tune, I have yet to address it. My original config file didn't include a lambda PID, so I'm not quite sure I ever really trusted that I had this set up correctly, surely not enough to make changes through BlueCat.

I will give your config file shot and try and scan another scan and post it back and maybe you can take a look. Scanning on the street is always a challenge as most of us know, my ZL1 gets so loud at WOT it attracts way too much attention.

This 12' ZL1/motor has 5000 miles on it and was upgraded at about 1500 miles with everything that is listed in my signature. The Kenne Bell BAP and larger lower pulley were just added as I stated in the thread intro. This motor made 722 rwh in Open Loop but wasn't tuned on the Dyno, just 2 pulls. This motor has seen 7,800, so I'm ok with the 7000 rpm on the BTR Stage 2 cam and valve train.

If your running long tubes you need to change your O2 settings if you haven't. This way you'll have accurate Air Fuel ratio control. I have been multiplying O2 proportional by .835 and then integrator delay by 1.1 to 1.4 something. You'll just have to drive it while watching your wideband and O2 switch points to see what's best. The boost a pump works on fuel pump control module setups? Haven't had to worry about it as I've seen very little benefit of BAP's. Usually wind up with a burnt up fuel pump and having to upgrade the pump in the end anyway...

AS for rpms... 7800 - Really? I've revved a stock LSA to 7100 and thought for sure I was fixing to blow something since stock valve springs start giving out on these things right around 6800. Plus stock power band seems to top out right around 6500 to 6600. I'm currently with very good valve springs only revving to 6800 redline. I know right around 7000 the superchargers seem to hit a whole new boost level, but just doesn't seem worth it to me to have a $15000 motor fly apart... Think Brian would advise against it too even with his springs.

I took the car out and scanned with your config file. I noticed 2 unsupported parameters and the gauge display isn't displaying correctly, but I went ahead and drove the car a bit anyway. Unfortunately the car got really warm and I was only able to get 1 half ass pull and the car was smoking the tires between shifts. Anyway, let me know if the scanning data we need is there and I will attempt to get better data. Thanks again for all the help.

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Originally Posted by GHuggins

If your running long tubes you need to change your O2 settings if you haven't. This way you'll have accurate Air Fuel ratio control. I have been multiplying O2 proportional by .835 and then integrator delay by 1.1 to 1.4 something. You'll just have to drive it while watching your wideband and O2 switch points to see what's best. The boost a pump works on fuel pump control module setups? Haven't had to worry about it as I've seen very little benefit of BAP's. Usually wind up with a burnt up fuel pump and having to upgrade the pump in the end anyway...

AS for rpms... 7800 - Really? I've revved a stock LSA to 7100 and thought for sure I was fixing to blow something since stock valve springs start giving out on these things right around 6800. Plus stock power band seems to top out right around 6500 to 6600. I'm currently with very good valve springs only revving to 6800 redline. I know right around 7000 the superchargers seem to hit a whole new boost level, but just doesn't seem worth it to me to have a $15000 motor fly apart... Think Brian would advise against it too even with his springs.

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My extreme cutoff is set to 6800 as well. Thanks for the heads up on the O2 settings, I will need to double check and see where I am. Thanks for taking the time to post!

Ok a couple quick things I see are...

Fuel mixtures are very inconsistent. The O2's are not working pretty much at all. They are trying to switch, but the fueling is so far off it's not switching the O2's properly. Do what GHuggins said about tuning the O2's for long tube headers. The other thing is that your wideband is reacting slowly, like my PLX Bosch 4.2 did when I had it. If it's possible, I would switch to the new Bosch LSU 4.9 sensor setup, it's WAY faster and will give you WAY more accurate information. One example is look closely at the wideband readings when you go from 0 throttle to WOT. By looking at the injection rates, transient fueling is giving it a shot of extra fuel on initial throttle opening. Notice how the wideband is still reading super lean for a little bit until it goes rich? Also notice that the narrowbands ARE going full rich right away, much faster reacting than the wideband? This means that there is information there that is at best missing, and at worse, incorrect. If you tune by the wideband, you would falsely think it was too lean on initial WOT hits. It doesn't look like it actually is by looking at the narrowbands and injection rates. BTW, this is general, good info for any of you other guys reading this.

That's all I can give you for right now, sorry.

You shouldn't be going above your rev limit if it's indeed set to 6800... I bet one or more of your torque limits for Neutral, Park or something like this is maxed not allowing rev limits to work. Made that mistake once myself...

Like GM said, you need to get your fueling and O2 settings dialed in so they actually do what they're supposed to do. It sounds like your running super rich in open loop. I bet if you put it into closed loop, your fuel trims might be close to -10's or more. A lot of widebands out there can't have their settings changed and sample either too fast or too slow and wind up throwing fueling out that much or more. A good wideband is very important.

Here's a screenshot from your log that shows what I'm talking about with the wideband reaction. If you compare what the narrowband is reading and what the wideband is reading you can see that the wideband is pretty far behind the narrowband readings. (I know this is kind of hard from just a picture without a detailed explanation of what I'm seeing.) It takes the narrowband about 50ms to switch from full lean to full rich at the same time it's taking the wideband about 450ms to make the same change. (Look at the white line vs the blue line) It takes about 125ms for my PLX wideband to make that same change. I'm a big fan of the new 4.9 Bosch sensors, they read very accurately and quickly. Widebands don't normally switch as fast as narrowbands just by the nature of their design, but they should react faster than ~450ms. Just my opinion and my fwiw.

http://i841.photobucket.com/albums/z...20reaction.jpg

Great info thanks. I have the NGK AFX and haven't had an issue like this before. I bought it new 2 years ago and maybe its time for a new sensor. I appreciate your input on this, but it looks like I need to sort out my Wide band data before making any changes. So close, yet so far away, all I can do is keep trying. Thanks again for your time and input all.

Just be careful. In that picture your afr is showing near 15 and you are full throttle in boost. It could be just lagging, but I would want to be sure of that before it causes some damage.