Tuning and 02 sensors

[07heri]

I know the whole 02 sensor placement issue has been beat to death but I could use some opinions on something.  We're tuning an 08 Softail.  The sensors placement and depth suck, as everyone knows.  So we're thinking how do we take a bad situation and make it not so bad.

Here are some questions I would like some opinions on.  If it something that will make it better, that's cool.  If it's a bad idea, say it's a bad idea, that's cool too.

One idea was to just use flat sensor bungs.  Yes, that would point the tip upwards, which isn't ideal because of the potential for condensation.  Would this kill the sensors pretty quickly or over time?  Just how detrimental is this to the sensors?  If it's something that shortens the sensors lifespan how long could one expect the sensors to last.  This is one way to get the tip all the way into the pipe.  Obviously, this isn't according to spec, location of curve and upward angle, but still better than the OEM sensor depth. 

The second idea would be to pull the shields and have flat bungs welded on the outside curve of the pipe.  This would be more in line with how Bosch recommends placing the sensors.  Tune the bike.  Then plug the bungs.  The shields will cover the bungs.  Then put the 02 sensors back in the OEM bungs to avoid CEL and just run it open loop.  Basically just use the sensors in the correct pipe area to tune to get the VE's correct then open loop it.  We lose the closed loop functionality but I kinda think it would be a better tune than what we'd get with the crappy OEM sensor setup. 

Just looking for ideas to make a crappy situation not so crappy.   

[strokerjlk]

Sounds like a good plan to me.
What about the 80-100 kpa areas?
The thing is , if you are going to have it dynoed anyway for wot , your not gaining anything.
You get to play around and learn something. But it still needs dynoed .

[KiwiRob]

Carefully trimming and shortening the bung heights would move the sensor tips further into the exhaust stream, along with moving them closer to the ports would do the trick. - Rob

[KiwiRob]

opps

[redmtrckl]

Here's one that Piper Performance is working on that has a D&D fatcat on a V-Rod. This pipe is ceramic coated and has no heat shields. The bungs were angled on the inside radius and as expected the O2 sensors would not sample. You can see in the first pic where the original bung location is. Only about an 1/8 inch of the sensor tip was in the exhaust stream. Cliff welded in new bungs as shown in the attached pics and now they are sampling as they should. He is tuning this bike with TTS.  WOT afr's will be done with Herco blocks.
It has the SE big bore kit, cams, injectors etc.

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[redmtrckl]

Overall view

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[Buglet]

  Why would you use the blocks instead of the bungs.

[mayor]

  Why would you use the blocks instead of the bungs.

if you want to keep the bike in closed loop mode while adjusting the open loop cells, you need both (or a pipe sniffer). 

[redmtrckl]

Easier to get to. However I miss-spoke. The open loop will be done the old fashioned way with copper tubes

[mayor]

well, at least I added that disclaimer.   

[07heri]

Carefully trimming and shortening the bung heights would move the sensor tips further into the exhaust stream, along with moving them closer to the ports would do the trick. - Rob

Have looked at the bungs?  Not much to trim.  I doubt it would do much.

My question to all is what to do with A Softail.  Anyone that has looked at one will easily see there's not much that can be done with placement, especially the rear.  My first thought is how long will the sensors last if pointing upwards rather than parallel.

[KiwiRob]

Here are a couple of pics to give you an idea of the original position of the V&H pipes I have, and the re-located position of the sensors and bungs. As you say, on a Soft Tail, it's a bit of a squeeze on the rear pipe, but it can be done. - Rob

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[wolf_59]

Here is how I did mine although different exhaust but might give you an idea


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[wolf_59]

Also I just use flat sensor bungs (18X1.5 mm half nut turned down on a lathe), I drill the hole in the pipe then use a die grinder to elongate the hole so the nut sets in the pipe on the high ends so it kind of cradles it.


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[FLTRI]

Great pics guys and FWIW looks to me like both mods will provide good signaling.
Do they run well in closed loop?
Bob

[rbabos]

Carefully trimming and shortening the bung heights would move the sensor tips further into the exhaust stream, along with moving them closer to the ports would do the trick. - Rob

Have looked at the bungs?  Not much to trim.  I doubt it would do much.

My question to all is what to do with A Softail.  Anyone that has looked at one will easily see there's not much that can be done with placement, especially the rear.  My first thought is how long will the sensors last if pointing upwards rather than parallel.

Had the same issue with my softail. No damn room where you want it and only thing left was having them stick out from the outer rad of the pipe with a huge hole in the heat shield. Would look absolutely Front pipe is more doable but no point just doing one. Some pipes might have the bends more accommidating but the ST didn't.
Ron

[07heri]

Carefully trimming and shortening the bung heights would move the sensor tips further into the exhaust stream, along with moving them closer to the ports would do the trick. - Rob

Have looked at the bungs?  Not much to trim.  I doubt it would do much.

My question to all is what to do with A Softail.  Anyone that has looked at one will easily see there's not much that can be done with placement, especially the rear.  My first thought is how long will the sensors last if pointing upwards rather than parallel.

Had the same issue with my softail. No damn room where you want it and only thing left was having them stick out from the outer rad of the pipe with a huge hole in the heat shield. Would look absolutely Front pipe is more doable but no point just doing one. Some pipes might have the bends more accommidating but the ST didn't.
Ron

You're right.  There's no room to reposition them.  Short of heating up the pipe and knocking a dent in it to accept a flat bung that sits parallel the only other option is to have the sensor tip pointing upwards.  At least the entire tip will be in the exhaust stream.  Granted, it ain't correct but it has to read better than what it's doing now.  Bungs are free so I think he wants to do it.  Can it be any worse than the stock set up...lol?    If he has to spend 90 bucks every 25k on sensors and they read better then I think it's worth it.  I hate half azzing things but sometimes you have to just say WTF and do it.

[wolf_59]

Great pics guys and FWIW looks to me like both mods will provide good signaling.
Do they run well in closed loop?
Bob

On the histogram O2 switching looks like a strobe light
No issue with closed loop VTune at 447 clb to set ve's then adjust clb's to 700 seems to works for me 

[wolf_59]

You're right.  There's no room to reposition them.  Short of heating up the pipe and knocking a dent in it to accept a flat bung that sits parallel the only other option is to have the sensor tip pointing upwards.  At least the entire tip will be in the exhaust stream.  Granted, it ain't correct but it has to read better than what it's doing now.  Bungs are free so I think he wants to do it.  Can it be any worse than the stock set up...lol?    If he has to spend 90 bucks every 25k on sensors and they read better then I think it's worth it.  I hate half azzing things but sometimes you have to just say WTF and do it.

Steve Cole recommended in a post to use a large flat punch to flatten a spot on the pipe for the bung, I found it easier to elongate the hole 

[07heri]

Here are a couple of pics to give you an idea of the original position of the V&H pipes I have, and the re-located position of the sensors and bungs. As you say, on a Soft Tail, it's a bit of a squeeze on the rear pipe, but it can be done. - Rob

Have you noticed anything positive from this position.  Might be the pics, but they don't look any better than the stock position.  How much of the tip is in the pipe?

[07heri]

You're right.  There's no room to reposition them.  Short of heating up the pipe and knocking a dent in it to accept a flat bung that sits parallel the only other option is to have the sensor tip pointing upwards.  At least the entire tip will be in the exhaust stream.  Granted, it ain't correct but it has to read better than what it's doing now.  Bungs are free so I think he wants to do it.  Can it be any worse than the stock set up...lol?    If he has to spend 90 bucks every 25k on sensors and they read better then I think it's worth it.  I hate half azzing things but sometimes you have to just say WTF and do it.

Steve Cole recommended in a post to use a large flat punch to flatten a spot on the pipe for the bung, I found it easier to elongate the hole

Elongating the hole isn't the issue.  The pipe is at such angle that the bung needs to have a slant cut to keep it parallel.  There's so much angle that the lower side of the bung is just as long as the tip so it's hidden in the bung.  What I was asking about was if someone had a workaround for the depth. 

Have any of you guys that see alot of bikes run across any aftermarket head pipes or full exhausts that have fixed this specifically for the Softails? 

[KiwiRob]

Here are a couple of pics to give you an idea of the original position of the V&H pipes I have, and the re-located position of the sensors and bungs. As you say, on a Soft Tail, it's a bit of a squeeze on the rear pipe, but it can be done. - Rob

Have you noticed anything positive from this position.  Might be the pics, but they don't look any better than the stock position.  How much of the tip is in the pipe?

The re-positioning  of the sensors, closer to the exhaust port made quite a difference to the VTuning on my old 96cid engine. The pics show clearly the sensor bungs have been moved, although the bung length doesn't look much shorter, it is.
With the same pipes on my 113cid, I am having some difficulty gathering good data in the low rpm high map areas which didn't happen with the old engine. I don't think (hope) that the sensor positions would be the problem. - Rob

[07heri]

Here are a couple of pics to give you an idea of the original position of the V&H pipes I have, and the re-located position of the sensors and bungs. As you say, on a Soft Tail, it's a bit of a squeeze on the rear pipe, but it can be done. - Rob

Have you noticed anything positive from this position.  Might be the pics, but they don't look any better than the stock position.  How much of the tip is in the pipe?

The re-positioning  of the sensors, closer to the exhaust port made quite a difference to the VTuning on my old 96cid engine. The pics show clearly the sensor bungs have been moved, although the bung length doesn't look much shorter, it is.
With the same pipes on my 113cid, I am having some difficulty gathering good data in the low rpm high map areas which didn't happen with the old engine. I don't think (hope) that the sensor positions would be the problem. - Rob

Same here.  I notice PV giving the errors, ve+ open 02's fr and rr, way more frequently below around 2250/2500 rpms.  Get above that and it seems collect hits pretty nicely.  What's frustrating is taking the time to try to learn this stuff, making tons of data runs, and not being able to overcome something as stupid as wrong placement and depth.  Thanks .

[strokerjlk]

Here are a couple of pics to give you an idea of the original position of the V&H pipes I have, and the re-located position of the sensors and bungs. As you say, on a Soft Tail, it's a bit of a squeeze on the rear pipe, but it can be done. - Rob

Have you noticed anything positive from this position.  Might be the pics, but they don't look any better than the stock position.  How much of the tip is in the pipe?

The re-positioning  of the sensors, closer to the exhaust port made quite a difference to the VTuning on my old 96cid engine. The pics show clearly the sensor bungs have been moved, although the bung length doesn't look much shorter, it is.
With the same pipes on my 113cid, I am having some difficulty gathering good data in the low rpm high map areas which didn't happen with the old engine. I don't think (hope) that the sensor positions would be the problem. - Rob

Same here.  I notice PV giving the errors, ve+ open 02's fr and rr, way more frequently below around 2250/2500 rpms.  Get above that and it seems collect hits pretty nicely.  What's frustrating is taking the time to try to learn this stuff, making tons of data runs, and not being able to overcome something as stupid as wrong placement and depth.  Thanks .

At least you see the problem , and admit there is a problem.
Diff bung locations may help you sample consistent .but once you identify the areas that won't stay closed loop friendly, don't use closed loop there .
That's the problem with a blanket of closed loop,covering the majority of the  map .one bad apple spoils the whole darn map.

[FLTRI]

That's the problem with a blanket of closed loop,covering the majority of the  map .one bad apple spoils the whole darn map.

Yep. That's precisely why any full-time 100% closed loop system doesn't work.
Bob