Hilly,

If you really want to keep the stock headers, could you just adjust your AFR table so that it would only be in Open Loop. Then you wouldn't need to worry about AFV changing the tune on you.

I was talking to a dyno operator recently and he says he only uses closed loop for Idle. Mind you he tunes mostly cars and some water cooled bikes, so air cooled V-Twins might be a different story.

Don't really know meself just food for thought is all, but maybe closed loop isn't be all end all.

Hilly

Take a look at how little of the O2 sensor is sticking inside your front pipe and you can see the issue easy enough. You can cut down the bung on the pipe and it does help a lot for low RPM issues. There are post on an easy tool for cutting them down over on the HTT site in the US.

The problem gets worse as you lower the exhaust pressure. Let's think about what is going on and then it will all make sense. In order for it to properly measure what is in the exhaust, the exhaust must first travel past the sensor to measure it. The sensor is NOT what you see yet the part that is under the cover and it must travel through the slots in the cover for it to get to the sensor element. Take away the pressure and the exhaust doesn't flow through the cover! Place the sensor in a low pressure area of the pipe, same issue. This is nothing new but most of the so called HD tuners are not willing to learn and understand and that becomes the bigger issue. Most people just think it a smog device so do not use it but they are dead wrong! Make it work like it should and it becomes your friend.

Go look at a new 2012 and you will find that HD has relocated the sensors on most all models as they have found the issue as well and that's with a cat and restrictive muffles in place!

All you can do is shorten them up the best you can. I've not found any yet that you can make too short. I did have a customer that was a welder cut his bungs out and locate new ones right over the old holes and it looked very nice without getting it rechromed. He told me he could not believe the difference once he got it back running and looked at the O2 data. With the stock position it took 4 minutes for the sensors to start working from a cold start and they dropped in and out. With his modification to the bungs only afterwards the same test again and the O2's were up and running in 2 minutes and never dropped back off during his test.

Hilly pics of what you do with measurements would be appreciated. After reading what steve has said things start to fall into place with me.

SO far it seems good. The clunk has completely gone. Still go a whirr coming from the primary though, but I had that with the old one as well. Gear changes seem smoother, I am going to run it for a month and then drop the case and have a look. You would have read about the fretting? that they have seen in the US due to lack of oil getting into the inner parts. The fix is to cut some groves against rotation with a dremel so that it picks up the oil and throws it into the inside. A Simple mod that seems that they all swear by. I will wait and see though. Other than that, I am chasing a very small oil leak around the oil filter, oil cooler. I run a Jagg and KP so one of the seals are leaking slightly. I will end up drooping the filter and remover the adapter to see where it is coming from. Either the gaskets have lost their sealing properties or the adapter has come loose on the retaining nut. Other than that things are well.

Next project is 103, and maybe a new crank. 07 had issues with twisting so that will be a big one for me. And maybe some head work to boot. Hell I will be spending a couple of grand on the work so why not go a little bit further. That will wait for a while though as it will take a while to save the dollars......Unless I can sell my wife and kids.......

On another note with the O2 Bungs. After reading Steve post on the position of the sensors, I can understand now. When I run a O2 Data my front is a lot slower to adjust than the rear. And I swapped then around as well with the same issue. I am wondering if adjusting the depth of the bungs will help make the sensors more responsive due to being deeper into the exhaust flow. Seems plausible enough, and a really simple job to fix as well. Just have to look at the HTT site and get that info.