I got to your pictures via editing of the link in the e-mail alerts. Here are four pictures that i took today that appear to be near identical to your set-up:

 

http://i1122.photobucket.com/albums/...ocation003.jpg
http://i1122.photobucket.com/albums/...ocation001.jpg

I hope these links work, any way a good welder could hook you up.

 

Angled bungs are NOT the way to go. It leaves too much of the sensor out of the exhaust flow on the high side of the bungs. Harley got away with this at the beginning because of the restrictive exhausts. Also you just cant stick the bung anywhere you feel. Where they are positioned in the exhaust stream affects how they read. Go to the Bosch website and you can read up on proper positioning.

 

i don't know if this will help you or not.. i took exh from a road glide and fabbed them to my 07 fatboy. i had to install bungs in the pipe since the rg o2 were the pencil style and located in the collector.. anyways, you can see where the rear o2 is and you can tell where the frt is by the heat marks where i burned through the pipe on the opposite side with the torch. i used the location from the original pipes as a starting point. the frt was easy, the rear took some careful measuring and placement. the 02s will definitely go in on a angle and they don't stick into the exh stream all that much, maybe 5/16" . look in your original pipe with a 02 installed and you'll see its not much at all.

 

2000FiveOh - perhaps you can post the URL? I appreciate the suggestion but finding the information you reference on the Bosch web site is proving to be a bit intimidating........ It's a big company w/ a lot of products.

I don't engineer exhaust or engine Control Systems for a living. I leave that to the Vance & Hines, D & D, etc. folks. That's the reason I took pictures of what the production version of the exhaust w/ bungs look like.

Thanks, D

 

Thanks Froggy. Whose ECM and "autotune" are you using (if aftermarket).

Hows the placement function w/ the ECM , etc?

D

 

well, against popular belief, i use no ecm upgrade. i installed new spark plugs at the time and checked them in 500 miles or so. they came out grayish to tan so its not running to lean. BUT as you can see i am not running a true dual setup with larger pipes. i think with maintaining the 2-1 collector it has enough back pressure to allow for the factory ecm to properly adjust the a/f mixture with the original 02's..

i get decent mpg's at 45 in the summer, 41 now that its gotten colder, no backfiring, no decel pop.. it works just fine.. and the mrs right leg and foot thank me..

 

Thanks. I don't do that well on my 88. It's been running 35 to 38 mpg and that is after a custom tune. I'm at 71 hp and 71 Ft Lb (at the wheel) and very flat. I did add Hard Kore baffles to the BSS and that created enough back pressure to eliminate most of the decel pop, etc. Have not pulled a dyno run since I added the baffles but it should have enriched the mixture some. I did not see a big change in MPG however.

Everything is still running in Open Loop since I do not currently have O2 sensors. I want to do some "tuning" for hp, torque and mileage so I really need to add the O2 sensors which is what generated this thread in the first place.

Thanks to all for their inputs. This is a really great Forum!!!!!!!

D

 

Wide-band O2 Sensor info - Being an Engineer by training, I tend to dig deeply into "design" on occasion. I found the technical design document for the Bosch LSU 4.2 O2 sensor in case someone is bored or wants to be put to sleep.

You can find it Here:

http://www.daytona-sensors.com/download/Bosch_LSU4.pdf

As to the mounting requirements you should look at section 9 and specifically at paragraph 9.4./ Bosch suggests that the sensor be angled at least 10 degrees away from the exhaust stream. They even talk about using a longer threaded boss (bung) to keep the sensor from seeing excessive exhaust gas temperatures ( over 500 degrees C).

Enjoy, D

 

It's not saying it's 10 degrees away from the exhaust stream. What's it's saying is the correct way to mount the the bung is to have a 10 degree angle pointing downward so any condensation drips off and doesnt settle inside the vanes on the sensor. Take a close look at the diagram and you will see the bung is mounted at a 90 degree angle to the surface of the pipe. By mounting it at a 90 degree angle the entire sensor is in the exhaust stream. You can't/shouldn't place the bung at the 3 o'clock position on the pipe and then angle it up 10 degrees. Correct way would be to mount it at the 2 o'clock position so it points downward BUT it still enters the pipe at a 90 degree angle. It doesn't matter where it comes in, 3, 2,1 o'clock position but it should enter at a 90 degree angle to the pipe surface. Which means the bung should have the same depth 360 degrees, not cut at an angle.

Now look at the earlier HD set up. The bung is mounted in such an extreme angle that the o2 sensor goes in and only 1/3 of the sensor is in the exhaust stream. Not the best design and I believe was changed on the newer smaller o2 sensors. Just a guess, the bungs were slopped on the pipe where it would fit easiest with little consideration as to how much of the sensor was actually in the exhaust stream. Will it work? Somewhat, as it obviously does. Is it 100% effective? No.

The best way to deal with high temps is use a hand held temp guage. Measure and mount accordingly.