Help me understand the Power Commander

[HOF]

I have a pretty much stock 2005 engine-wise. From what I have read, the PC III helps reset the engine for guys who have added things like mufflers etc. so that their engines can better use their added upgrades.

My question is, for a bike without these performance enhancing add-ons would a PC III help my bike run better/smoother? It is not that it runs badly now but I do like it when I can have my toys running as good as I can. What exactly will one of these units do for my bike?

I have searched the forum and have found a lot of discussion on the PC but have not been able to find discussions that will answer these questions. If there is a post out there that discusses this and I have missed it, just send me in the right direction and I will be grateful. I am sure Ignacio will point me in the right direction.

 

[madmike2]

The bottom line....its supposed to help smooth out the flat spots int he HP/Torque curves and stop the "searching" and "surging" some experience. Mine is OEM and I sometimes run Holeshot slip-ons with no PCIII.

From our friends at Google:

PCIII sute:fjrforum.com

power commander site:fjrforum.com

 

[Toecutter]

Here's a promising testimonial, from this thread.

 

[germany]

+1 to the "promising testimonial" linked by TC.

I am an expert "fifty-pencer" in the corners. Having the PCIII installed makes small throttle changes (on and off) less abrupt (the front end doesn't dive or raise) thus giving me a bit more confidence.

I'll PM you with a link to where I purchased mine.

 

[FJRay]

I had a PC installed mainly because it was almost free. The local dealer at WFO-4 wanted to sell some to the folks visiting so I got mine for a stupid low price and the dyno and mapping was free. My 03 ran as well as I thought possible but it was noticeably better after the PC install.

I latter added Muzzy cans and it didn't change much. I took them off because the noise was to much on long trips. Bottom line is that it can help but in most cases it isn't mandatory for a stocker and the key is getting it mapped by somebody that has the right stuff. I think the available maps are ok but all engines are different and a custom map done on a dyno is the way to go for the best results. I get 50mpg if I am not to aggresive on the throttle.

 

[jekirby]

My bike being an 07 ran really poorly at the low rmp range--something that I was expecting after reading posts here before I bought mine. I understood that this was primarily due to emission restrictions. Anyway after riding the bike a while I was very dissatisfied with its low rpm performance and bought a PCIIUSB at a show very cheap. I had a blast looking for and installing a few different maps I found here. It really is a kick(for us nerds) to hook a bike up to a laptop. Bottom line, the bike is totally different. I ws really not expecting that much of a difference. Stock map was good--Wally's map was great. I would do it in a heart beat. And yes..I did also install a g2ergo throttle tube...being an 07 something you won't need on your 05.

 

[markjenn]

What the PC really is doing is enrichening the bike across the board, particularly in the mid-range. PC can do this because they're not encumbered by having to pass any emissions tests that constrain what Yamaha can do. (This may change soon.) All emissions-constrained engines will run a bit smoother and make slightly more power if they're running richer.

Nobody seems to care, but by installing a PC, you are increasing emissions by large amounts. You're probably putting out about 50x what a current-technology car puts out in unburned HC. And I think the stock bike, at least my stock 2005, injects very nicely. I can perhaps detect some slightly surging in the mid-range, but only if I look for it. I'm probably in the minority with this farkle-happy crowd, but I view a PC on a stock bike as pretty marginal performance mod compared to things like suspension and brake upgrades.

- Mark

 

[odot]

In other words......

screw the ecosystem.

There ain't no smog problem in kalifornia.

 

[Bounce]

by installing a PC, you are increasing emissions by large amounts. You're probably putting out about 50x what a current-technology car puts out in unburned HC.

care to back that supposition up with some real data?

i don't see it happening when every emmissions test i've ever had done (even on my just-sold 96 GMC truck was at least 10x (usually more) BELOW the target levels for pass/fail. in most cases, the readouts i've seen are 2 decimal placed below the target. if all you do is install a PC3 and keep the cat/com on the bike, i can't see where there's much that the PC3 can do to affect emmissions enough to make that big of a jump.

since without some hard data to back up such a claim, you might want to go hug a different tree. we're busy barking up this one.

 

[Toecutter]

In other words......
screw the ecosystem.

There ain't no smog problem in kalifornia.

For the record, I didn't install a PCIII and my bike is completely CA-compliant. I figured a PCIII would probably deliver less fuel economy, and I'm happy with the stock performance level, but others' MMV.

 

[odot]

And remember, kids.....

YOU CAN FERTILIZE YOUR LAWN WITH USED MOTOR OIL.

:blink:

 

[jekirby]

This is a serious question/observation, but I am interested what direction it takes...here goes: One can usually get an idea by how the bike is running (rich/lean/blow-by) by the condition of or build up in the tail pipes. I know that my bike run richer , but so far I don't notice any problems based on what my tail pipes look like. heh,heh,heh.

I fully believe everyone should do his/her part for our home, but really, the total number of bikes, the total miles, the total number of bikes with pciii's; don't assume that those with pciii's don't care.

Be gentle with me......this is not my first time....and no I am not encouraging a pc debate.

 

[Fred W]

What the PC really is doing is enrichening the bike across the board, particularly in the mid-range. PC can do this because they're not encumbered by having to pass any emissions tests that constrain what Yamaha can do. (This may change soon.) All emissions-constrained engines will run a bit smoother and make slightly more power if they're running richer.
- Mark

What you say above is untrue.

The PC3 does not necessarily enrich the mixture, and it doesn't do it across the board or particularly in the midrange. It depends entirely on what map that is loaded. Ideally a map will be derived experimentally (via a dyno) to provide the best fuel air ratio under all conditions.

The PCIII map is like a spreadsheet where the vertical axis (rows) are engine rpm in 500 rpm steps and the horizontal axis(columns) are the throttle position in percent reported by the TPS (0,2,5,10,20,40,60,80,100). The PCIII can and will actually lean out the mixture from stock if negative values are loaded into the cells, if that is what it takes to get the best mixture.

The stock map on an FJR (as well as many other bikes) is excruciatingly lean in the low throttle opening, low to mid rpm areas. Why? Because that is where they measure emissions performance, so that is where they run the mixture leaner than what is optimum for rideability, in order to satisfy those measurements. This lean mixture causes the engine to "surge" when operated in those conditions: small throttle opening, low to mid rpm. Which is, coincidentally where the bike is operated when cruising around on back roads, etc.

This is not a new phenomenon occurring only on fuel injected bikes. Carburetted engines would show these same exact symptoms if the pilot circuits were adjusted too lean, or became partially blocked.

Many folks say they can't feel the surging, or that they feel it but it doesn't bother them. Just because they can't feel it doesn't mean it isn't happening. There is no "surging" felt on the highway, or when driven briskly on back roads, because the throttle is open far enough to place the stock ECU's fuel map into an area that is not so dramatically lean.

The main advantage of the PCIII, and the reason that I have one, is to get rid of the lean surge condition, which I find to be extremely objectionable on an other wise buttery smooth operating bike. You can also use the PCIII to enrich the mixture at higher throttle openings and higher rpms after making mods to the intake and exhaust and result in an increase in horsepower, but that is not the goal of most PCIII users on FJRs.

 

[odot]

Doesn't matter what the pcIII does....I'm still fertilizing my lawn with used motor oil. :glare:

 

[jekirby]

Doesn't matter what the pcIII does....I'm still fertilizing my lawn with used motor oil. :glare:

Makes good french fries also

 

[markjenn]

by installing a PC, you are increasing emissions by large amounts. You're probably putting out about 50x what a current-technology car puts out in unburned HC.

care to back that supposition up with some real data?

Sorry I don't have a database of emissions tests for FJRs without and without PC's compared to current technology cars. But it is widely known that these aftermarket systems dramatically increase HC emissions and cars are already an order of magnitude cleaner than bikes to begin with. So I'll let it go at that - I doubt any data I can show you is going to convince you anyway. But if Yamaha could pass an emissions test with a PC-like richer fuel map that adds power and reduces surging, then don't you think they would? And finally there's an existence proof that if PC's are distributed to solve fueling issues associated with lean-running emissions standards, then I tihnk you can safely conclude that they're going to raise emissions.

From here we go into the "well the greenies are all weenies anyway" or "my one bike isn't significant" or "they should go after the other guy because he's worse" arguments. They're all valid to an extent and I don't hold it against anyone if they want to PC their bike. But I'll hold to my opinion (and that's all it is) that PC's are a marginal enhancement to most FJR's which inject pretty well and I've ridden quite a few. There are always outlyers and some bikes run different than others, so this is not a one-size-fits-all question.

- Mark

 

[markjenn]

Many folks say they can't feel the surging, or that they feel it but it doesn't bother them. Just because they can't feel it doesn't mean it isn't happening.

Unsure what the point is of solving a surging problem you can't feel.

- Mark

 

[Fred W]

Many folks say they can't feel the surging, or that they feel it but it doesn't bother them. Just because they can't feel it doesn't mean it isn't happening.

Unsure what the point is of solving a surging problem you can't feel.

- Mark

I'm not trying to convince you that you should get a PCIII, Mark. No I'm far from a PCIII evangalist. I'm just trying to explain why other people might have one.

In other words, just because you think you don't need one does not negate the needs/desires of anyone else.

Get it?

And please, lets not go down the slippery slope of the "increased pollution" arguments. To begin with you have no hard data to back up your assertions as to the extent of the pollution increasing.

But, perhaps even more fundamentally, if one was really concerned with their own pollution they shouldn't be riding any bikes, or driving any cars, especially recreationally, which most of us do. Instead, they should walk, ride a bicycle, or stay home.

Philosophically, it's all a matter of degrees. Where does one put a stake in the ground and say, this much pollution that I am making is OK, but that much pollution that you are making is excessive.

 

[ionbeam]

My question is, for a bike without these performance enhancing add-ons would a PC III help my bike run better/smoother? It is not that it runs badly now but I do like it when I can have my toys running as good as I can. What exactly will one of these units do for my bike?

Yamaha hasn’t done the best job of driveability with the FJR FI system; however, it does meet emission standards well into the future. In addition to allowing the owner/user to compensate for altered intake & exhaust systems, the PCIII will address driveability issues for owners that have problems (not all do, some don’t notice, some don’t care).

I have installed a PCIII for driveability issues, in my case to moderate wicked surging. This is not a perceived issue, I have made actual measurements that show engine vacuum, rpm and fuel pressure fluctuations that coincide with my passengers head moving back and forth, the headlight bouncing up and down and me experiencing what I would call surging. I’ve telemetered up my bike with gauges and meters Velcroed to the bars, then I have ridden with them so I could observe what is happening. I was hopeful that this would lead to a solution in place of masking the problem with a PCIII.

I have not been able to find one ‘smoking gun’ that is responsible for my surging. I have observed that by dampening the vacuum to the Fuel Pressure regulator in my Gen I takes a lot of the sting out of the surging. I would assume that my FJR is giving up a bit of throttle response in trade for this dampening but haven’t investigated it. Gen II fuel pressure is managed by a very different method.

Score: ionbeam -- 0; PCIII -- 1.

One glaring shortfall of the PCIII for the FJR is the inability to manage spark mapping. I would just love to be able to trim spark timing as well as fuel injection.

As far as the O2 sensor goes, it is operational in only very narrow situations, where "...the ECU applies minute corrections to the basic injection duration...to maintain a stoichiometric air-fuel ratio of 14.7:1". In the diagram below note that item 5 is the fuel trim based on the input from the O2 sensor. Also note area H/6 is the fuel CUTOFF/decel when the throttle is closed.

As far as the PCIII killing the environment – I’m not going there. I will note that in a counter intuitive way, leaning out the FI shot (to a point) will actually improve performance. Adding fuel until gas drips out the exhaust doesn’t lead to better performance in a street engine. Lean FI does have problems – surging, high combustion chamber temps and it creates hard to clean emissions. I’m sure that Yamaha is just as concerned about lean emissions as rich emissions.

The PCIII for the FJR is just a slight fuel trim device which also offers a way to soften throttle tip-in and lead-out edges. The FI shot timing and basic volume is still determined by the ECU, the PCIII just offers a way to optimize it for system variances and user intentions.

The following table is the PCIII 502 map for a European spec FJR with slip-ons. Note that at lower rpms and smaller throttle openings it significantly enriches the fuel trim. Rich mixtures tend to give a softer throttle response and when excessively rich leads to ‘bogging’. Now note that at higher throttle settings the PCIII actually leans out the FI shot. There are still significant operational areas where the PCIII simply is ‘hands off’. The low rpm enrichment leads to hydrocarbon emissions and the leaner throttle trim leads to nitrogen based emissions (vary broad interpretation, ignoring carbon and some NOx compounds).

Use the PCIII for driveability issues, to optimize engine performance and compensate for intake/exhaust modifications.

The O2 sensor instructs the ECU to make tiny fuel trims over a narrow range of engine temperatures and throttle settings.

While the PCIII will add fuel, it also trims out fuel under higher throttle settings.

Pollution? While you are setting at a traffic light you are getting zero mpg. When you start your FJR and don’t ride off, all you are doing is producing pollution for zero vehicle miles traveled. Every trip you take just for pleasure essentially adds unnecessary emission pollution and unnecessary fuel consumption. Even after fattening up the lower throttle FI percentage the FJR still remains a very clean machine.

JUST GO RIDE.