89 non cat hunting idle and cut out
05-09-2018, 10:46 AM
#46
Nordschleife Master
Change your coding plug to a cat car and add a factory fit NB O2 sensor. This is much better than the CO pot and will always be self adjusting.
Do not use the simulated NB output of any WB O2 sensor system. It will work OK, then swing wildly and cause you to chase your tail!
Do not use the simulated NB output of any WB O2 sensor system. It will work OK, then swing wildly and cause you to chase your tail!
see here for pics of the bits including where to drill the hole
https://rennlist.com/forums/928-foru...ml#post9790904
05-09-2018, 11:47 AM
#47
Rennlist Member
Yep agree with Colin..
see here for pics of the bits including where to drill the hole
https://rennlist.com/forums/928-foru...ml#post9790904
see here for pics of the bits including where to drill the hole
https://rennlist.com/forums/928-foru...ml#post9790904
To me putting an NBO2 on a non cat vehicle is an unnecessary expense and effort- if it serves a positive purpose fair enough.
Rgds
Fred
05-09-2018, 02:42 PM
#48
Rennlist Member
Much appreciate if you chaps can advise why you would recommend changing to NBO2 on a car that is going to be custom shark tuned. All I do is set the CO pot to the null position and then put sharktuner on autotune to fill the cruise map.
To me putting an NBO2 on a non cat vehicle is an unnecessary expense and effort- if it serves a positive purpose fair enough.
Rgds
Fred
To me putting an NBO2 on a non cat vehicle is an unnecessary expense and effort- if it serves a positive purpose fair enough.
Rgds
Fred
Doesnt mean that you need a cat..the CO pot is pretty close, but..if youre willing to do a $30k car right, can can soak up $70 O2 sensor.
It just covers all of the bases. And you can still tune WOT with the ST and a WB nicely too, but the base map and LT/ST trims set by the NB, help everywhere else and also keep the WOT enrichment clean.
Its the same deal as following the widom of doing a -complete- top end refresh...see how that helped, same wisdom here. Theres nothing to loose, a laundry list of goodness to gain.
05-09-2018, 04:06 PM
#49
Rennlist Member
The ECU really wants a NB02, autotune on the ST just gets you running with WB02 input...and the ECU doesnt like a WB simulated input.
Doesnt mean that you need a cat..the CO pot is pretty close, but..if youre willing to do a $30k car right, can can soak up $70 O2 sensor.
It just covers all of the bases. And you can still tune WOT with the ST and a WB nicely too, but the base map and LT/ST trims set by the NB, help everywhere else and also keep the WOT enrichment clean.
Its the same deal as following the widom of doing a -complete- top end refresh...see how that helped, same wisdom here. Theres nothing to loose, a laundry list of goodness to gain.
Doesnt mean that you need a cat..the CO pot is pretty close, but..if youre willing to do a $30k car right, can can soak up $70 O2 sensor.
It just covers all of the bases. And you can still tune WOT with the ST and a WB nicely too, but the base map and LT/ST trims set by the NB, help everywhere else and also keep the WOT enrichment clean.
Its the same deal as following the widom of doing a -complete- top end refresh...see how that helped, same wisdom here. Theres nothing to loose, a laundry list of goodness to gain.
The NBO2 sensor is more a legalistic requirement and not a technically advantageous device in that it can only resolve whether the mix is stoich, rich or lean . The WBO2 can happily resolve down to 0.1 of an AFR unit and do so over a wide range of values- do you feel that a NBO2 has a better resolution? That the NBO2 can be fed into the LH and modulate in real time is what it is but they became a legal requirement to stop folks like us from dicking around with the air fuel mix.
I think [respectfully] you may be underestimating how good the autotune function really is but the bottom line is when you have it one can study just how well it is performing and make adjustments as deemed appropriate- one cannot do this with a NBO2 in modulating.control. To be clear, I do not know what kind of accuracy the NBO2 can generate but I cannot see anyway it can be better than with a WBO2 and a good shark tune.
Regarding the WOT throttle map, as I understand once the WOT switch contact is made the NBO2 is ignored completely and fuelling is defined by the summation of the cruise map values and the WOT map values. Smarter folks tell ST2 to ignore the WOT map and simply tune the upper range of the cruise map to give the AFR values required.
I guess it all boils down to what one is familiar with. I have been using ST2 on my non cat motor for the last 10 years and am more than happy that I am not obliged to use a NBO2. I can also lean off the cruise map a bit to improve fuel economy but when fuel prices were about a fifth of what they were back in the UK, I just could not be bothered. Now that they have nearly doubled in the last year or so I have the capability to optimise should I so choose,
05-09-2018, 06:06 PM
#50
Rennlist Member
I rather suspect you boys are too preoccupied with keeping the smog ***** happy.!
The NBO2 sensor is more a legalistic requirement and not a technically advantageous device in that it can only resolve whether the mix is stoich, rich or lean . The WBO2 can happily resolve down to 0.1 of an AFR unit and do so over a wide range of values- do you feel that a NBO2 has a better resolution? That the NBO2 can be fed into the LH and modulate in real time is what it is but they became a legal requirement to stop folks like us from dicking around with the air fuel mix.
I think [respectfully] you may be underestimating how good the autotune function really is but the bottom line is when you have it one can study just how well it is performing and make adjustments as deemed appropriate- one cannot do this with a NBO2 in modulating.control. To be clear, I do not know what kind of accuracy the NBO2 can generate but I cannot see anyway it can be better than with a WBO2 and a good shark tune.
But needing cats has nothing to do with what a NB02 can do to benefit you.
Regarding the WOT throttle map, as I understand once the WOT switch contact is made the NBO2 is ignored completely and fuelling is defined by the summation of the cruise map values and the WOT map values. Smarter folks tell ST2 to ignore the WOT map and simply tune the upper range of the cruise map to give the AFR values required.
I guess it all boils down to what one is familiar with. I have been using ST2 on my non cat motor for the last 10 years and am more than happy that I am not obliged to use a NBO2. I can also lean off the cruise map a bit to improve fuel economy but when fuel prices were about a fifth of what they were back in the UK, I just could not be bothered. Now that they have nearly doubled in the last year or so I have the capability to optimise should I so choose,
The NBO2 sensor is more a legalistic requirement and not a technically advantageous device in that it can only resolve whether the mix is stoich, rich or lean . The WBO2 can happily resolve down to 0.1 of an AFR unit and do so over a wide range of values- do you feel that a NBO2 has a better resolution? That the NBO2 can be fed into the LH and modulate in real time is what it is but they became a legal requirement to stop folks like us from dicking around with the air fuel mix.
I think [respectfully] you may be underestimating how good the autotune function really is but the bottom line is when you have it one can study just how well it is performing and make adjustments as deemed appropriate- one cannot do this with a NBO2 in modulating.control. To be clear, I do not know what kind of accuracy the NBO2 can generate but I cannot see anyway it can be better than with a WBO2 and a good shark tune.
But needing cats has nothing to do with what a NB02 can do to benefit you.
Regarding the WOT throttle map, as I understand once the WOT switch contact is made the NBO2 is ignored completely and fuelling is defined by the summation of the cruise map values and the WOT map values. Smarter folks tell ST2 to ignore the WOT map and simply tune the upper range of the cruise map to give the AFR values required.
I guess it all boils down to what one is familiar with. I have been using ST2 on my non cat motor for the last 10 years and am more than happy that I am not obliged to use a NBO2. I can also lean off the cruise map a bit to improve fuel economy but when fuel prices were about a fifth of what they were back in the UK, I just could not be bothered. Now that they have nearly doubled in the last year or so I have the capability to optimise should I so choose,
IMHO, the smog **** requires cats...so what..if you pass smog youre being told you're a good maintenance steward for the car. In fact, the history of a car passing smog or not (avail online)...is a great tool to judge stewardship of an unknown used car.
Really doesnt matter if you need cats or not...IMHO theres no reason not to have em.
05-09-2018, 06:54 PM
#51
Rennlist Member
Has nothing to do with smog *****. Its keeping a really tight nice smooth fuel curve fed to the car that self corrects for thing aging or not working as they did brand new. Things wander..injectors, sensors..esp MAF...
IMHO, the smog **** requires cats...so what..if you pass smog youre being told you're a good maintenance steward for the car. In fact, the history of a car passing smog or not (avail online)...is a great tool to judge stewardship of an unknown used car.
Really doesnt matter if you need cats or not...IMHO theres no reason not to have em.
IMHO, the smog **** requires cats...so what..if you pass smog youre being told you're a good maintenance steward for the car. In fact, the history of a car passing smog or not (avail online)...is a great tool to judge stewardship of an unknown used car.
Really doesnt matter if you need cats or not...IMHO theres no reason not to have em.
Fitting an NBO2 when it is not there to start with and is not legally required is just so counterintuitive to me. NBO2 devices are not as fast as WBO2 and as I am aware are not as accurate as WBO2 devices that are more expensive to start with.
05-10-2018, 10:20 AM
#52
Pro
Thread Starter
I am interested in making the change to add a NB set up, do you think it works ok if I fitted it to one of the exhaust manifolds as I have an existing bung I could use.
I think it’s the optimum choice to keep everything in tune.
I think it’s the optimum choice to keep everything in tune.
Last edited by Marti; 05-10-2018 at 12:02 PM.
05-10-2018, 11:42 AM
#54
Rennlist Member
When you have ST2 and no NBO2 [ both Marti and myself have such setup], I have listed the reasons why I believe installing NBO2 is detrimental. Whilst I agree with you that things degrade with use/time, ST2 helps one see exactly what is going on and easily facilitate a correction or identify a need for component replacement. Things that degrade do not do so overnight generally speaking and if one leaves ST2 permanently connected [I do not] taking some readings and analysing the data on Sharkplotter is uber easy as is making adjustments.
Fitting an NBO2 when it is not there to start with and is not legally required is just so counterintuitive to me. NBO2 devices are not as fast as WBO2 and as I am aware are not as accurate as WBO2 devices that are more expensive to start with.
Fitting an NBO2 when it is not there to start with and is not legally required is just so counterintuitive to me. NBO2 devices are not as fast as WBO2 and as I am aware are not as accurate as WBO2 devices that are more expensive to start with.
Yes, when you use it.
I have one too, guess how often it's in the car adjusting for stuff.
