All your comments are much appreciated and well-taken. FYI, I took the bike out this morning for a 3-hour, 140 mile ride through some canyons, into the Malibu mountains, and lots of freeway at about 75 mph. OAT in the low 90s most of the way.

The results, compared to before the recent dyno:

- Throttle response MUCH crisper in all ranges
- Noticeable seat-of-pants improvement in acceleration
- Gas mileage improved from 30 mpg to just under 34 mpg (!)

None of the above implies that any of your comments were not right on the mark, and that better performance awaits the hand of an expert tuner. It does imply that I may wait until my next engine mod before investing hundreds of dollars in an expert tune. For now, "good enough" might just be good enough.

Thanks to all who replied. I appreciate the generous expertise.

 

Hmmm ... I suppose the Procharger w/ 12 lb boost doesn't hurt ...

Nothing wrong with that Ed ... what I would've done, too ... most likely ....

* * *

Correct me if I'm wrong about the Power Commander III (PC III) ... I don't have one, nor have I studied them much ....

I used to sport a Dobeck Techlusion 'Digital Fuel Optimizer' variously referred to as a TFI or DFO ... it was a 'three pot' system (i.e., three potentiometers or variable resistors) that piggy-backed on the stock ECM and EFI .... All it could do was to add fuel to (i) low range, (ii) high range and (iii) acceleration ....

Actually, sgod1100 was correct when referencing the very left-hand most end of the curve ... which then rapidly went to very rich ....

My assumption is that the PC III is similar to the three-pot system and that is why the lower end and upper end of the RPM range seem to be a little disjointed ... the stock ECM is trying to adjust the AFR, but the PC III is just muddying the water ....

If you were to use a Screamin' Eagle Pro Super Tuner (variously SEPST, SEST, or old SERT), MasterTune TTS, ThunderMax AT or Accel (forget the name of their system) ... you (your tuner) could adjust the timing curve as well as have full control over the AFR curves ....

While a reputable tuner who takes the time to make multiple runs on your bike (i.e., more than 4 ... a dozen or so maybe) ... can dial in your AFR a little to improve the tune, I think you will continue to be somewhat limited ....

When a Dyno tune is done, the graph will begin around 2,000 RPM because the bike is run up (shifted through the gears) to 5th gear or whatever gear gives a 1-to-1 final transmission ratio ... so since the rear wheel is turning on the dyno, the shift will occur at something above idle speed ... that might also explain the high AFR (lean part) of the beginning of the curve ... as the throttle had just been released to shift and twisted to run the motor up to the redline as the graph shows ....

Also note, the AFR graph typically is very compressed ... you might want to request a separate read with the scale expanded so the AFR over the RPM range is readable and can be properly explained by the tuner ... assuming he has a good understanding and can explain it ....

R/
'Chop

 

Your assumption is not correct. I am familiar with the old DFO's as well as the Power Commander. I used to have the power commander and I had a neighbor who had the DFO. The Power Commander is much like the SERT, where as you can tune any given rpm, at any given throttle position, and make timing or fuel changes. Just as you would a SERT.

And if you are looking at the little "blip" and the very beggining of the AFR map, that indeed is normal and misleading. You see that on many sheets. The OP definately had a huge rich dip following the meaningless lean spot, that lasted throughout his normal riding range.

In reality, his bike was in no way lean at any point.

 

I'm sure th OP will appreciate your clarifying the info in my post ... that's why I hedged my reply ....

Learn something new every day ....

 

 

some good comments ,and some off the wall stuff here.
as stated the AFR line is only a indication of WOT. and it dosent need to be straight. diff rpms with diff pipes require more or less fuel.
the bike is not being ran through the gears in a wot run. it is taken to 1:1 ratio whatever that gear may be. then it is twisted to wot and the sampling button is pushed.
the chart gives an indication of the hp/tq curve and tells you what you are doing at wot nothing more. the hp/tq readings at "normal riding " will not be anywhere what the sheet says.(say 2700 rpm) why??? less fuel less intake flow and hopefully diff timing.
so say using ed's sheet if your cruising at 3000 rpms at steady state no way will it be making 100 tq. nice sheet Ed by the way. been a while sense I seen that one.
I agree that this particular tune or pulls probably was 8 runs. the 4 runs was the previous tune. note the dates.BUT not all tuners sample or hit the run button for every run on the dyno. At least I dont. so it is possible to get a complete tune with a sheet only showing 8 runs. a lot of times I will put the base run on one file then go back to it when I am finished and getting a few final pulls.... after all the runs on the brake and the runs checking timing.. then when I am satisfied I go to the original run file with the base pull on it and spool some runs up. this way I can delete the timing and tweaking runs and only clutter up the saved file with the final runs.
here is one that shows 8 runs ...but it really had about 50 to tweak timing and tweak AFR. then I returned to the original and made a few to record the final sheets to give to the customer.

 

Probably talkin' about me ... ... oh well ....

I read everything I can ... try to reconcile the conflicting **** by trying to identify the most credible and authoritative sources ... (and make sense of it based on sound science/physics and engineering principles) ....

Still learning and trying to pass on good gouge (as best I can discern) ....

 

nothing wrong with that.
I read to much myself. LOL

 

and i think the AFR being so lean at start, then rich, then lean wouldn't have been conducive to optimum performance. I was (and still am) amazed that your bike reached those #'s with those AFR readings. My limited knowledge of tuning tells me the bike need to be mostly rich 13.2-13.7 for optimum performance. Yours started at 18 and went as low as 10. I'm surprised the bike wouldn't stall at start off. It wasn't until the bike hit 4000rpm that things seemed to make sense (to me) I was under the impression that this was a dyno tune not just a dyno run. While the #'s are impressive the tune itself didn't make sense. Thus the reason for my first response.

 

I'm just running the stock one right now...The main reason i haven't got cams yet is because i have heard that once 130-140hp is attained the balancer chain (since my engine is the 96B) has a chance of breaking. I didn't want to take that chance. I plan on getting the engine re-done (dynamically balanced crank, pistons, rods, etc) next winter. Going to be going through Frank at Drago's bike works (most likely the 107"). I'll probably then go with the SE 211. i have heard good things about it when mated with the procharger.