I got a look at the new PC III USB EX whose claim to fame is that it is street legal in the Republik of Kalifornia. Score another round for the EPA. Here is an excerpt from the PC III USB EX's User Guide for the 2007 Dyna:

"On the PC III USB EX units you will notice that there is an area of the map that is highlighted gray. Within this area you are not able to make adjustments to your fuel curve."

The sample map shown in the User Guide has gray area on everything less than 50% throttle opening and everything less than 4750 rpm! They are still charging $369 for a tuner that effectively won't tune where you ride. What percentage of your time do you spend with your throttle at 50% or better or at 4750 rpm or better?

 

So if you put a high flow AC and new pipes on with one of these Power Commander EX units to compensate, doesn't that mean you don't really need the PC EX? Apparently the O2 sensors in closed loop on 2007s can compensate for higher air flow.

 

From Dynaglider-
"So if you put a high flow AC and new pipes on with one of these Power Commander EX units to compensate, doesn't that mean you don't really need the PC EX? Apparently the O2 sensors in closed loop on 2007s can compensate for higher air flow."

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06 FXD black

Well I don't know about that . . . .I have a 07 Heritage Softail that was starving for fuel at any speed! It surged horribly and ran hot as hell all the time. The dealer(s) were of no use with the typical "blame the EPA not us- we can't change anything without you spending about $850 with us." Yeah right!!!!
I said to hell with this and the useless warranty and got mine Dyno'd, tuned, mapped with a PC III USB and out the door with 18 more HP, 22 Ft Lb Torque all with stock pipes!!! No more fried thigh, pinging, misfiring and surging. It's a sjame to spend $20k on a scoot and then have to cough up $$$ to make it run right. [:@]

 

the ex is fully adjustable over 50% throttle. not just over a specific rpm. the o2 sensors only adjust the map under 50% throttle. after changing components, the bike needs to be ridden for 100-150 miles before the ecm really finishes tuning in the lower throttle settings. an 06 dyna or 07 any model, cannot be diagnosed as faulty untill there is that many miles on the bike.

If you had that many miles on the bike, the 02 sensors may have been faulty, (they are quite easy to make malfunction, as easy as silicone fumes getting to them once).


I am a firm believer in the Power Commander and the o2 sensor eliminators. it makes it to that the epa's fingers are out of your engine.

 

harleymojoman wrote: I have a 07 Heritage Softail that was starving for fuel at any speed! It surged horribly and ran hot as hell all the time ... got mine Dyno'd, tuned, mapped with a PC III USB

That's kind of where I was going with this. The need is still there to richen the fuel air mixture. In your case, even your stock setup needed help. I'm glad the good old Power Commander was still available to you. But if the day comes when only the EX model is available, a huge area of your riding range will be off limits to tuning.

 

jmetro wrote: the ex is fully adjustable over 50% throttle. not just over a specific rpm.

PC maps are a grid of cells showing percentage change of fuel at specific throttle and rpm settings. Throttle across the top and rpm down the side. You can't define a square are on a grid without specifying both factors. And the sample map shown in the EX's User Guide had a square-shaped gray area on everything less than 50% throttle opening and everything less than 4750 rpm. So until you are at 50% throttle AND 4750 rpm, you can't adjust your fuel delivery.

 

I've used and tuned this power commander. the grid is adjustable from 500-6200 rpm over 50% throttle.

 

jmetro wrote: I've used and tuned this power commander. the grid is adjustable from 500-6200 rpm over 50% throttle.

For which bike was that? I infer (but certainly don't know) that the gray area of non-adjustability varies from model to model.

Furthermore, the PC III USB EX User's Guide for 2007 Dyna says the following:

On bikes that come stock with an O2 sensor it is necessary to keep the sensor connected to the bike. Since the O2 sensor is constantly monitoring the air/fuel ratio the ECM will keep this ratio around 14.7:1. If you were to try to make adjustments within the closed loop area of the map the ECM would trim the base map within itself to maintain a 14.7:1 air/fuel ratio. On some models the closed loop area of the bike may extend outside the highlighted gray area of the PC III USB EX map. In these situations you may find that even though you have altered a cell outside the gray area that the fuel curve does not change. This would indicate that at this point the bike is still in closed loop.

I find it interesting that you may not even be able to adjust outside the gray area.

What I still wantto know is how effective the Harley system is at keeping the air/fuelmix near the 14.7ideal. I've understood that it only trims fuel, because it is a system dedicated to reducing emmissions and, as a nice side effect,maximizing fuel economy. This says to me that you can be running lean and the EFI with O2 sensorswill not be able to add fuel. You willrun lean, with all of the problems that can bring.

But I haven't found anyone whocan confirm one way or the other. Perhaps the EFI in the 2007 modelscan add fuel to bring a lean condition back to the ideal. Certainly no one claimedthat was true for the 2006 Dynas.

 

Below 50% throttle cannot be adjusted at any RPM range on the PCIII EX.

 

So is it still worth $369 to anyone?