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[tmitchellofpg]

I have a similar question to an earlier post, asking about sensors on a 2006.
My 2005 SEFB has 1 3/4" drag pipes, with no baffles, and runs perfect that way. It is just annoyingly loud. To quiet it down a bit, I just installed some universal, 13" long, drag pipe, baffles. When I first put them in, they sounded like they were really stifling the exhaust, so I pried the majority of the tabs open in the baffles, then I wrapped the baffle with some moose muffler packing. This quieted the exhaust enough for my taste.
I went to the dealer to get the fiberglass packing and asked the service guy if I need to re-tune for this. He said the EFI should adjust enough and it shouldn't take but 50 miles or so.
I just got back from a 60 mile ride and the bike ran fine. My question is how does the EFI know if it needs to adjust without having sensors?
Tom

[kona76]

Hi, and welcome aboard. I am not the techy guy here, however I might have something to say once in a while.

I believe the 2005 DOES NOT self adjust with just the ECU. The later models 2006 and later have a closed loop system, with sensors on the key points of the exhaust to measure such data for self adjustment of air and fuel flow.

On a 2005, you can install a Alpha N Mentor Closed Loop aftermarket that follows the exact amount of miles you mentioned; 50. I also think any bolt on addition to intake or exhaust requires a Dyno adjustment although sometimes the changes are hardly significant. I have this option on my 2005 SE FatBoy, and in a few words " the thing works".

I think the person you spoke of was probably thinking of a newer model.

Welcome and enjoy the best site on the web.

Mike K.
kona76

[SE08RK]

Darn, I wish you guys were....well, with the can-do attitude you have, you'd be an asset to anyone's shop.

The '05 EFI/ECM has no way (as stated) to make any modifications to the system what-so-ever since it is totally open loop (no O2  sensors). The ECM must be programmed or mapped to set the AFR.

The '06 can, but is very limited. The system is not a fully closed loop system since the O2 sensors are only a high (lean or optimum) range or stoichiometric sensors. The portion that is closed loop is upward of 3200 RPMs and is a span up to another setting like 3600 or so. Then the system does not have the capability to make the large changes required for an exhaust system change or other increased air flow modification. The '06 and up ECM AFR system is basically to satisfy the system changes required for barometric pressure changes and altitude (limited even in the US) and for the EPA's materialistic standards. But there exist replacement ECM's that will do what Harley fails to do.

Check Thundermax and/or Daytona Twin Tec for a system for these bikes that is fully closed loop. That means you set your style and replace your pipes and intake to your pleasure - the ECM makes the AFR map per your desire. As soon as one is available for this FLHRSE4 - it is a done deal! And this has NO affect on HD's engine warranty!

BC

[kona76]

By the way, you have a great looking ride. The beauty of this color combination always takes me to a higher plane.

As my humble opinion goes, the MOCO must take huge leaps in technology, design and performance to out-class this fine example of an American Motorcycle. Some of the 2008 models may have done just this. However, the 2005 SE FatBoy really sets standards for excellence in manufacturing and will always have a place in history as one of the finest "custom" production motorcycles ever.

Mike K.
Kona76

[tmitchellofpg]

By the way, you have a great looking ride. The beauty of this color combination always takes me to a higher plane.

As my humble opinion goes, the MOCO must take huge leaps in technology, design and performance to out-class this fine example of an American Motorcycle. Some of the 2008 models may have done just this. However, the 2005 SE FatBoy really sets standards for excellence in manufacturing and will always have a place in history as one of the finest "custom" production motorcycles ever.

Mike K.
Kona76

Thanks,
Tom