R1100S- O2 plug, techlusion v booster, to run cored Duc cans?
 

99 R1100S, 70K. Stock, for now.

Wanting to drop the cat and cans and run my cored Ducati cans on this bike. Have not found answers yet to the following (although lots of info)-

1) Do I need to allow for the O2 sensor to still be part of the system, and without the cat, where would the best place be to mount it?

2) Can I eliminate the O2 plug altogether, and if so, how?

3) I'm on the fence as far as booster plug versus Techlusion, having read that the booster should suffice to handle the leaning after removing the cat, but would the techlusion/PC3 be better suited? Do not mind tuning at all.

Thanks

I think the lamba sensor (O2) is just for the closed loop part of the EFI system. It leans the A/F ratio out after a predetermined time at steady throttle. For giving good fuel economy at highway speeds.

Might be wrong tho, Im a carby man LOL.

Thanx
Dave

I'm can't remember at what RPM the O2 sensor stops having a meaningful effect but I think it was around 3000 RPM. Above that RPM it has no input, below that RPM the Motronic module uses O2 sensor signal data to decide whether to lean the mixture or not. If you spend lots of time at low RPM you'll be getting worse fuel economy.

I had the Techlusion and had removed the O2 sensor. The Techlusion cannot lean out but only richen the mixture at three points in the RPM range. Best done on a dyno although others here have done it seat of the pants for a decent result.

You didn't say which Duc cans you're using. I fitted a single carbon fibre Termignoni can on my R1150GS. It was LOUD! In hindsight a single can was probably restictive, loud or not. Regardless, after about a year, the metal inlet cap split and that was the end of that experiment.

did I say it was LOUD?

It is not at a certain RPM Twodear.........but rather at a certain butterfly angle........where the O2 sensor is bypassed and I think that is at 75 degrees open of the 90 degrees available. Correct please if others think different.

Thanks Dr. C

that would explain why I didn't really notice that the O2 sensor had been removed, the throttle had only two positions - Off and WFO

The cans are the stocks off a 1098. I have the baffles so if these things are too damned loud, I'll 'uncore' them. My stock exhaust rattles like an empty spray paint can. At least it drowns out the squeaking shocks, my next big ticket purchase.

So if I decide to pull the catcon, what do I do with the plug?

Dr Curve, I feel honored to have your response on my thread since 20 years and 2 months ago you handed me an A on my final project for your class! I do solely blame you for my decades long obsession with airheads though. That has cost me some serious bank over the years!

Well it must have been a good project because I did not give too many straight A's. I still have a couple of Airheads and will always love them as well. Hope the exhaust project goes well and that your life went, more or less, as planned. This is a wonderful forum with lots of input from many fine sources so please stay with us here as long as you have BMW bikes. Thanks for the kind comments about our class together.