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Discussion Starter · #1 ·
is it advisable to disconnect or remove the o2 sensors once you have achieved a good tune by applying the blms.then turning off auto tune mode.i ask this because of the cost of replacing the sensors .they certainly have a tendency to fail more frequently than i like.im running two bikes and clock up a decent mileage.i avoid short trips. but still ive replaced three sets in 50000km.here in nz ive just paid nearly 500nzbucks for two from dtt..amazon used to sell them for half that but no longer have stock.
 

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Ron may chime in but once tune is complete lock it in and remove the O2 sensors. No need to keep them changing the tune any more unless big changes in the engine have been made, from what I've heard. Use them only to establish the proper tune, then remove, save, plug exhaust bungs and ride on. (y):cool:
 

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is it advisable to disconnect or remove the o2 sensors once you have achieved a good tune by applying the blms.then turning off auto tune mode.i ask this because of the cost of replacing the sensors .they certainly have a tendency to fail more frequently than i like.im running two bikes and clock up a decent mileage.i avoid short trips. but still ive replaced three sets in 50000km.here in nz ive just paid nearly 500nzbucks for two from dtt..amazon used to sell them for half that but no longer have stock.
Some tree hugger will argue but if the tune is pretty much centered, there will be little gain to running them on the bike full time in closed loop all the time. The +/- daily trim adjustments would be minimal once a good tune has been established. Hell, 02-07 ran no sensors, open loop all the time.
Ron
 

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The WEGO uses standard Bosch LSU 4.2 sensors used on a VW production application (Bosch P/N 0 258 007 057/058 or VW P/N 021 906 262B).

So you can buy way cheaper units from the local automotive store if only you can replace connectors some how.

My vote goes closed loop all the time since I am tree hugger big time. You do not disable them from your car either. 50000km for three sets is less than it should be even they are not located optimally in v-rod. A little bit bad luck I guess. They do not like mechanical hits like dropping etc. Silicon is bad too.
 

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Discussion Starter · #8 ·
unfortunately i couldn't get the sensors to calibrate on the last time i checked the free air setting. The red lights stayed constant ,wouldn't flash. The blms went to the top of the scale and wouldn't move. However its an easy diagnosis and fix. Of course the symptoms were the tune went choppy and irregular.
 

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Yes there you know they are gone bad. Glad that you have practice to this already. But check those regular Bosch sensor availability in your country. Connector might fit or not. A little research. Only cheapest has been good enough for me what comes to Bosch brand LSU sensors. They have been used so many cars etc.

Of course you can disable closed loop but what is the point for that system then.
 

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Of course you can disable closed loop but what is the point for that system then.
mukle - so for DTT's ECU WEGO with no ION knock sensing timing retard in the system & running variable street gas maybe closed loop at all times would be preferred but if you run alcohol like you do for 300 Hp is closed loop at all times really needed ? What will change enough to require WB's to alter the tune if fuel is consistent Alcohol or high octane race gas ? Do you have an exhaust temp gauge on your Mad Scientist Big Power bike ? DTT had advertised that their system automatically changes the tune while the bike is ridden - is this true or do you look at EGT and adjust tune manually ?

I'm thinking a PCV with WB's on my Stage 2 R Model, using Delphi ECU with ION knock sense, after tune is stable lock tune in & remove O2 sensors and go open loop since knock sense is active and will pull timing if a batch of lower octane street gas gets in the tank - Ron & I discussed this before, plus if one or both O2 sensors burns out the bike won't run like crap in closed loop with them affecting the tune - Thanks for any input, thoughts, suggestions ! (y):cool:
 

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mukle - so for DTT's ECU WEGO with no ION knock sensing timing retard in the system & running variable street gas maybe closed loop at all times would be preferred but if you run alcohol like you do for 300 Hp is closed loop at all times really needed ? What will change enough to require WB's to alter the tune if fuel is consistent Alcohol or high octane race gas ? Do you have an exhaust temp gauge on your Mad Scientist Big Power bike ? DTT had advertised that their system automatically changes the tune while the bike is ridden - is this true or do you look at EGT and adjust tune manually ?

I'm thinking a PCV with WB's on my Stage 2 R Model, using Delphi ECU with ION knock sense, after tune is stable lock tune in & remove O2 sensors and go open loop since knock sense is active and will pull timing if a batch of lower octane street gas gets in the tank - Ron & I discussed this before, plus if one or both O2 sensors burns out the bike won't run like crap in closed loop with them affecting the tune - Thanks for any input, thoughts, suggestions ! (y):cool:
My take on this. A 02 failure can cause all kinds of weird shit to happen. Yes, even with the PC5 and Autotune. Works like this. Say your PCV calibration is calling for 13.5 AFR (which you can choose any AFR you like by editing the PCV cal and saving the changes), As you ride trims are formed via the sensors to target that AFR. You then send these trims via the software to the PCV cal. Over repeated riding the trim changes and sending trims, changes will be less and less, so the calibration is now built to offer the targeted AFR within the PCV cal. This PV5 cal is the pulse modifier that alters what the bikes ECM cal delivers the fuel at. Over the years and even in my experience with several tuners, plus what most pro tuners end up at is an error factor of about +/-5% of target. Tmax and DTT are also AlphaN and be it called trims or BLM it's the same process. Working with John, a member here and his TTS SC, PC5 and Autotune, last report was his changes are generally +/-2%, which is exceptional. The game plan was when to this state, remove the Autotune and sensors for two reasons. All that shit mickey mouse wiring and the risk of an 02 failure way down the road. Do you want an 02 failure in a boosted bike? Why risk it? Sure, you can continue running close loop forever if you wish but with +/- 2% the gain is next to nothing at that point. You have options. Many ways to do things. While you can't do this since your ECM isn't closed loop capable, some that use Target Tune for example stay with full closed loop via the module and wide band sensors. Some develop the tune with TT wide bands in the upper ranges, remove the TT module , install the stock NB sensors and dial in the common areas of closed loop and merge the two areas of the cal for best results.
Ron
 

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It does not do anything shit if you do not let it. Closed loop window can be narrowed after tune has been found. Let say there is one or two erratic updates from O2 sensors it does not freak out the system since they will be filtered naturally and corrected by the time. Updates are done via BLM tables which is statistical longer term process. Very similar than with cars. Simpler though since there is no long and short term fuel trim tables individually. But this is the whole concept of closed feed back. There is good books written about understanding control system theory.

Yes it is good question where you need loop back when the tune has been found? There is still many factors that can change situation like gasoline properties, ambient temperature, barometric pressure etc. Closed loop can then accommodate and optimize changes. In the street bikes you might want to get your mpg's great and emissions low. In the strip you can still change your strategy to open loop if desired. However I know people who rides much much meaner machines in the strip in closed loop.

DTT can be used as Alpha-N or Speed Density mode. Both versions are available for the VRFI. I work with latter one currently. It is more like three dimensional where is VE, RPM and TP used same time. Alpha-N is two dimensional. There is pros and cons for both methods.
 

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Great explanation Ron & mukle ! I'm thinking in the newer ECU's H-D used narrow bands due to more reliable and more of an EPA pollution control devise to target AFR a bit lean than the wide bands that work in a greater range of Rpm for tuning to whatever AFR you choose, at different Rpm's, but they may be less reliable long term.

At least for my early non NB feedback ECU it seems best to use the PCV & WB AT to get the tune right at my most often ridden in temp then lock it in and remove O2 sensors. I understand high overlap cams can mess up the standard OEM fueling so using PCV WB & going back to open loop after a proper WB auto tune is complete seems to make sense. DTT suggested to me to go open loop in cam overlap affected areas and closed loop in other ranges and run WB's at all times, from what I remember when I looked into this a few years ago. Ron +-2 up to +- 5 % seems to be a pretty damn accurate tune on a boosted bike, and still with OEM ION Sensing seems to be as good as it gets - not always an easy path for the average guy though, but then DTT install, setup and tune can be a bit daunting at first use as well I'm sure. Thanks Guys, great conversation - hope others that don't know all these details read it ! (y):cool:
 

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Great explanation Ron & mukle ! I'm thinking in the newer ECU's H-D used narrow bands due to more reliable and more of an EPA pollution control devise to target AFR a bit lean than the wide bands that work in a greater range of Rpm for tuning to whatever AFR you choose, at different Rpm's, but they may be less reliable long term.

At least for my early non NB feedback ECU it seems best to use the PCV & WB AT to get the tune right at my most often ridden in temp then lock it in and remove O2 sensors. I understand high overlap cams can mess up the standard OEM fueling so using PCV WB & going back to open loop after a proper WB auto tune is complete seems to make sense. DTT suggested to me to go open loop in cam overlap affected areas and closed loop in other ranges and run WB's at all times, from what I remember when I looked into this a few years ago. Ron +-2 up to +- 5 % seems to be a pretty damn accurate tune on a boosted bike, and still with OEM ION Sensing seems to be as good as it gets - not always an easy path for the average guy though, but then DTT install, setup and tune can be a bit daunting at first use as well I'm sure. Thanks Guys, great conversation - hope others that don't know all these details read it ! (y):cool:
High overlap cams can mess up the tuning process regardless of NB or WB tuning. This is generally in the area of 3k and down in rpms. Due to extreme reversion, the sensors are not reading the correct AFR, so the VE table is populated incorrectly during autotuning and the result is a poor running engine . A couple of methods to deal with this and dial it in for the problem areas. So based on incorrect feedback from the sensors, most will place that problem rpm zone into open loop to keep adaptive from screwing it up over time and keep good areas in closed loop, where it all plays well. Even stock cams on the Revolution have a good degree of reversion. The SE2 are even a bigger prick to dial in especially with NB sensors but it can be done. WB are a better choice in cases like that as you have more control over AFR then using a CLB table, like NB use.
Ron
 

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Yes agreed. Especially open/tuned exhausts in combination with high overlap camshafts can pull unburned mixture into exhaust. This can cause too rich afr indication.

In VRFI this reversion problem can be tackled by special values in BLM cells. Closed loop feedback is disabled in any cells with value 0. BLM update but not closed loop feedback is disabled in any BLM cells with value 1.
 

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One thing came into mind to original topic. Leaded fuel can reduce O2 sensors lifetime. Do not know can it bought anywhere from the gas stations anymore. Some high octane racing fuels can still contain lead.
True on the lead. Don't see any of that any more in my parts. I do read the odd time someone using Av gas with the goal of more hp. On a stock bike the exact opposite happens. Engine build dictates octane for the best outcome. That AV gas has extreme amounts of lead in it that can foul up more then just sensors . One other thing that can kill sensors is positioning in the pipe. While I like my Akrapovic exhaust, the sensor placement is the worst possible as in vertical, straight up. First start up moisture will run right into them, killing the life span. Seems they missed the memo from Bosch for correct sensor location. :(On some pipes, and most likely the Akra , often space dictates where they go rather then proper install for the bungs. So far, I've had no issues but I rarely start my bike in cold temps where that few seconds of internal sweating of pipe from combustion happens.
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No lead in US gas ............ only US bullets 🤪
True ! but like mukle said some high octane race gas still has it, and as Ron said 100LL "Low lead" :ROFLMAO: ( NOT ) 100 Octane Avgas has a LOT of lead in it. I used to mix 100LL and 93 Super unleaded 50/50 in my CR250 and YZ250WR race bike two strokes, and jetted properly, they absolutely fly ! - ( literally ) ! I wouldn't run that in my street gas Revo but a drag racer might - in that case removing O2 sensors quickly after tune is established is probably a good idea - anyone seen 100+ Octane Mogas anywhere or maybe best to just add Octane booster to 93 Super Unleaded ?

( Fun fact - in every country where lead was removed from auto gas the violence rate dropped dramatically - apparently lead makes people angry and possibly violent, when you regularly breath it in & it builds up in your system ) :oops:
 
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