Awesome write up. Now I see what you did and why.

This gives me something to play with when I get my AT.

Thanks for the patience describing this to me.

 

Let me know if any of it isn't clear, as some of it isn't easy to explain.

 

Not that I'm an expert, but my understanding is only the HD "Stage" ECM downloads are EPA compliant.

 

If the o2 sensors accurately and precisely measure the amount of oxygen needed to maintain A/F ratio, is a fuel map needed? The fuel will be metered by the o2 sensor response, right? or am I just not getting it. Maybe by fuel map you mean target setpoint of your A/F ratio? So a "Map" defines A/F Ratio setpoint for a given throttle position and the O2 Feedback is used to meter fuel to this setpoint I guess.

 

I did some limited CHT checks Saturday on a short ride that should've been longer but one of our group had an irreparable flat tire which required trailering it home. In closed-loop (lean), when the CHT had settled at about 226° at 55mph constant speed in about 85° air temps I switched to the rich base map (open-loop), and in a span of about five miles CHT had decreased to 221°, which is when the guy had his flat. I need to do more tests and will report back when I get some useful info.

 

With the PCV-AT, you can start with any base map that will allow the bike to start and run. Once it's going, it samples AFRs at 50x/sec. and makes ą adjustments to the trim tables, and that is what the PCV uses to determine the amount of fuel to provide. The further the base map is from ideal the longer it will take AT to auto-tune.

For example, if your base-map value at 2500 rpm @ 15% TP is 10 and the Target AFR spec is 14.0, at that point AT will adjust ą until it meets the spec. So, if it is running 13.5:1 with that base-map value it will subtract fuel until it meets the spec of 14.0. Your trim table value will be a negative number, let's say for example -5. The PCV then uses the base-map value of 10 and subtracts 5 giving a net value of 5. It does this sampling and makes changes 50x/sec., so you have real-time tuning going on at a very rapid rate.

 

What about timing changes to go along with your cam change?
Is this addressed with the PCV-AT? Or are they ignored with a PCV like the older PC programmers?

Different cams have varible timing requirements due to lift, duration, overlap, etc.

Spark profiles for a 255 cam are not the same as ones for a stock cam'd engine, a 260 cam or a 264 cam for example.

Dumping a bunch of fuel to mask a timing issue is not the right solution for a properly tuned bike IMO.

I don't mean to dump on your thread but I know when the wrong cam spark profiles are in my bike, it does not run the same and I have overheating problems.

Anything below 7% throttle opening probably means I'm in traffic or setting stopped so I have my VE tables set richer (14.2) to compensate for the lack of air movement since additional fuel helps cool as we know.

On the other end, I know that anything over 2750 rpms means I'm cruising at a higher rate of speed and again, this has more load on the engine and I feel needs addressed by adding slightly more fuel (14.5 to 14.4 AFR) so as not to overheat my engine.
IMO, if your engine is overheating at 55 mph at 14.6 to 1 in high gear, your timing is off.

I took a 450 mile trip last weekend two up and averaged 40+ mpg with a 113" engine. I never had any overheating issues in down town traffic or at 65 to 70 mph with 86 degrees temperatures. 70 mph on my bike has the air to fuel at 14.6 since it's under 2750rpm's.

Auto Tune is a great feature for but you really need to address timing requirements if you have made a cam change. TTS Mastertune (the only one "I" know of) allows you to change spark tables and then auto tune VE tables afterwards.

edit:
I just looked at spark timing tables for a stock cam 96" compared to a 255 cam'd bike; right in the 2000 to 2500 rpm range, the stock cam spark profiles are quite a bit higher which will create an overheating issue if you are trying to run at 14.6 to 1 air to fuel ratio.

There are 1000's of people out there running stock cam'd bikes that have bolt performance goodies that totally satisfy their needs and for them I'm sure the PC products address their needs but if you are changing cams, have plans to go bigger, etc, buy the right tool for the job.

I am only familar with TTS, SEST and PCIII. If the PCV allows for spark table changes, great and they should be addressed IMO.