Quick stupid question. Does PNP run closed loop? - Miata Turbo Forum - Boost cars, acquire cats.

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Old 07-03-2012, 09:10 PM   #1
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Default Quick stupid question. Does PNP run closed loop?

I managed to screw up my WB O2 sensor while installing inconel studs on the turbo. Either the penetrating lube I used to get the old studs out killed it, or banging it against the tranny trying to get the DP off & on did... either way I need a new one.

In the mean time, does the PNP MS1E I have ever run in closed loop under normal (track) driving? Or to put it another way, is there any risk of driving the thing with a bad O2 sensor?

Thanks for putting up with my ignorance

me=>
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Old 07-03-2012, 11:24 PM   #2
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Edit: Strike that, reverse it. x.x

Last edited by Nagase; 07-04-2012 at 06:55 AM.
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Old 07-03-2012, 11:30 PM   #3
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Depends if u have it turned on or not
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Old 07-03-2012, 11:42 PM   #4
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Quote:
Originally Posted by Handy Man View Post
In the mean time, does the PNP MS1E I have ever run in closed loop under normal (track) driving? Or to put it another way, is there any risk of driving the thing with a bad O2 sensor?
Depends on how you have it configured.

Basic Settings -> Exhaust Gas Settings, and
More Settings -> Lambda AFR Settings.

If you want to disable it, change "Authority" to 0 in the first menu.


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Closed loop means it's not changing fuel based on AFR.
Closed loop means it IS changing fuel based on AFR.
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Old 07-04-2012, 05:40 AM   #5
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Quote:
Originally Posted by Nagase View Post
Closed loop means it's not changing fuel based on AFR.

Closed loop is when the ECU effects changes based on the O2 sensors output, what you're talking about is open loop.

aka you have it *** backwards
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Old 07-04-2012, 10:19 AM   #6
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Thanks for the help! let me make sure I have this right:

my exhaust gas controller authority is currently set to 5%, so it has been running in closed loop during part throttle. I can disable closed loop by setting the authority to 0, which means its going to run solely on the fuel tables which will obviously be less than optimal, but should be safe... right? (of course this depends on how safe the fuel tables are, and I'm going to ASSume they are ok)
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Old 07-04-2012, 10:25 AM   #7
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correct.
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Old 07-04-2012, 07:22 PM   #8
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BTW, gentlemen, is wideband really needed for daily operation? My tuning guy is telling me that i can run on two narrow band O2 sensors and he can tune the car by shoving a long probe up the short custom exhaust that I have.

Granted that, can I drive the car after that with just regular O2 sensors? What's the disadvantage to that?
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Old 07-04-2012, 09:32 PM   #9
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I'm (obviously) no expert, but I did see an option to run the closed loop off of a narrowband O2 sensor in megatune, so I'd bet you can. And of course, if you had well tuned part throttle fuel tables you could just run open loop with no O2 sensor at all.

BTW, I had a slightly intelligent moment and tried "resetting" my innovative WB 02 and it seems to have fixed it

Last edited by Handy Man; 07-06-2012 at 09:34 AM.
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Old 07-05-2012, 01:17 AM   #10
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Quote:
Originally Posted by nile13 View Post
BTW, gentlemen, is wideband really needed for daily operation? My tuning guy is telling me that i can run on two narrow band O2 sensors and he can tune the car by shoving a long probe up the short custom exhaust that I have.

Granted that, can I drive the car after that with just regular O2 sensors? What's the disadvantage to that?
I'd get a different tuning guy.

Advantages of WBO2:
1. Autotune.
2. Even if you don't autotune, you can use Megalog Viewer and get a better fuel tune than your "tuning guy" could ever give you.
3. You can keep an eye on your AFRs in boost. A NBO2 does not output a usable signal at those AFRs. Injectors can clog after all. Would be a shame to blow an engine for something like that.

Other than these relatively significant advantages, there's no reason at all to run a WBO2.
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Old 07-05-2012, 01:35 AM   #11
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Not sure why boost is being mentioned. Neither am I sure how to tune a race car without dyno.
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Old 07-05-2012, 02:00 AM   #12
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Quote:
Originally Posted by nile13 View Post
Not sure why boost is being mentioned. Neither am I sure how to tune a race car without dyno.
Because that's when you're most likely to explode your engine? Only fuel can be tuned reasonably well off a dyno.
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Old 07-05-2012, 02:05 AM   #13
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I have a normally aspirated car. What boost?
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Old 07-05-2012, 09:33 AM   #14
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Quote:
Originally Posted by nile13 View Post
BTW, gentlemen, is wideband really needed for daily operation? My tuning guy is telling me that i can run on two narrow band O2 sensors and he can tune the car by shoving a long probe up the short custom exhaust that I have.

Granted that, can I drive the car after that with just regular O2 sensors? What's the disadvantage to that?

can he tune your carb too?
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Old 07-05-2012, 09:50 AM   #15
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might as well convert to 2-stroke too
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Old 07-05-2012, 12:06 PM   #16
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The question is fairly serious. After the car is tunes with wideband, is MS looking at wideband signal for normal operation?
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Old 07-05-2012, 12:08 PM   #17
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see post #3.
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Old 07-05-2012, 12:31 PM   #18
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Thanks, Brian. I saw it and understand it.

Let me re-phrase more specifically. Once the normally aspirated car is tuned, is there any advantage in running wideband sensor?
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Old 07-05-2012, 12:33 PM   #19
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considering tuning on NB is absolutely pointless, yes.
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Old 07-05-2012, 12:35 PM   #20
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/\ Interesting. Why is that? Is the stock setup "maxed out" from the factory?
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