Fuelly Badge


Wednesday, August 10, 2011

Power Commander V

While I was on holiday a package arrived from Bayside Performance. I've been interested in installing a PC5 on my VFR and I finally got around to ordering one.

What does it do?

It overrides the motorcycle's fuel injection system to alter the air/fuel ratio. It can be programmed at small incremental throttle openings in each gear.

Why install one?

Modern fuel-injected motorcycles must meet emissions standards and therefore have "lean spots" in the air/fuel map in order to pass the tests. A Power Commander with a proper map will eliminate the lean spots for an ideal air/fuel ratio and therefore improve performance and make the bike run more smoothly.

Fairings come off again... getting pretty quick at this now.

Honda left a perfect spot under the seat for a power commander

You need to pull the axle out of the tank to run the wires under it.

Plug and play.... almost.

This little hot-tap splices in to the throttle position wire.

Here's the fun part: installing the 02 optimizers. The rad needs to be partially removed to get your hands in there. The plugs can be dismounted from their frame bosses which makes them a little easier to work with.

I'm running the "jardine slip on, stock air filter" map from Dynojet. I can't imagine my Leo pipe really needing much different mapping. Maybe this winter if I've got money to burn I'll have a custom map done up. As long as the lean spots are tuned out I doubt anyone can tell the difference.

I went for a quick ride to try to feel the difference. It seemed to pull harder and more cleanly from lower revs, and the throttle reponse seemed crisper between 2500-5500RPM. I'll need to get it out for a proper ride to really evaluate the difference.

I have read some reports of the 02 optimizers throwing a fault code. Basically all they do is short out the 02 sensor signal to the ECM. Evidently, the VFR's computer is a little more sophisticated than they were expecting and isn't fooled by the optimizers. If I run into this problem I'll just hook the 02 sensors back up. My concern is that this will cause the PC5 and the ECU to "fight" over the fuel ratio and cause a surging. We shall see...

edit:  You'll probably need to zero out the throttle position on the power commander. Mine thought the throttle was open 5% when it was closed. CLick on "power commander tools>calibration tools>throttle calibration. Whatever the voltage reading is with your throttle closed, set that as the minimum. I think on mine it was 0.708 or something.


  1. You're telling me that for the install you didn't have to dig down to the fuel injectors! OMG that's fantastic news. I'm pretty sure I'm going to put mine right where I pulled out that huge Evap canister.

  2. That's one really cool thing about the 1200. Honda wired it more like a car than a bike, with each system on its own sub-harness, including the fuel injectors. All of the sub-harnesses are organized tidily on the left side of the bike.

    I wouldn't advise trying to install yours where the evap canister was for two reasons:
    1. you want the PCV somewhere that's easy to access so you can hook up your laptop through the USB plug. If it's under the tank you'll have to remove all the bodywork every time you want to connect to it.
    2. The power wire on the PCV harness is only long enough to reach the battery from under the seat. You would need to splice in a longer piece of wire.

    I've also pondered what to use that space for...what could I hide in there?

  3. The PCV is something that once it get's tuned properly I want to protect and hide as much as possible. Why would you need to get to it if it's working properly? I've found that the one on my race bike I leave alone. I know some ppl are always messing with it and it only seems to introduce problems. I'll have to see where the cables allow mounting, but we have to figure out something cool to do with that Evap can spot.

  4. small NOS bottle? Auxiliary fuel cell? It has to be something you wouldn't need access to very often.

  5. The first O2 "manipulators" were wired wrong. They have since fixed it. I'm running the 2 Bros map with my Leo. Tried the Jardine; felt the 2 Bros may be a teeny bit smoother. Like you say, probably either one is fine to use, and really doesn't need a custom map from a dyno run. I am running the BMC air filter and did the 1st/2nd gear mod, evap, and PAIR as well. AlanG

  6. You should come down to MMP this weekend. I'll have my VFR1200 in the talented hands of Matt Spencer on the dyno Saterday morning. A custom map at our elevation should be interesting. We'll also be loading the zero map, and stock maps for reference points, and then play with the 1st and 2nd gear limitations.

    Need a place to stay? I've got a guest room!

  7. I love SLC and MMP but unfortunately it is a 18 hour drive down i15 so I don't get down there very often.

    I have friends in the area and I would definitely like to get there more often. I went to the WSBK event a couple years in a row and did the Apex trackday right after. That's something I'd like to try to do again next year.

    I'm interested to see how your dyno work turns out.

  8. I sat down and chatted with my tuner tonight and shot the shit regarding the custom map. In particular how removing the O2 sensors from the bike will affect it. He said that the O2 sensors on motorcycles currently are very poor to begin with and the lambda sensors used in cars and the dyno are much more precise.

    Furthermore, the O2 sensors on bikes are only used below 2000 rpm's and at 20% throttle and less (Where emissions are checked). Above those set conditions, it's no longer a closed loop system.

    I asked if the bike would continue to modify fuel based on air temp and barometric pressure and he said absolutely. That's actually all done by the MAP sensor which is on the left hand side of our air boxes.

    When I was pulling all the PAIR junk off the bike I actually pulled the MAP sensor hose and plugged it. The bike idled fine, but once I gave it gas it died. This now makes sense because idling, it was below 2000k and less than 20% throttle. Once throttle was applied it no longer used the O2 sensor, but switched to the MAP sensor and promptly died.

    Just tid-bits of information I thought I'd pass along.

  9. I saw that you have reported 39-41 mpg fuel consumption earlier. Has it increased since you installed PC-V? I just installed PC-V and with map tuning I decreased the consumption from 32 to 34 mpg but nowhere near your values.

    My bike has only 800 km in it. I remember that you said somewhere that the consumption went down when the bike had 1000 km in the meter. What kind of values are talking about the then?

  10. If you take a look at my Fuelly.com log, you'll see that it wasn't until my 8th fuel-up that I started seeing high 30s MPG (US). Before I stopped tracking it I had averaged 39.9mpg overall. It will definitely improve after 1000 miles.

    My power commander didn't seem to change much for fuel consumption. I'm not using a custom map, just the jardine map from dynojet.

  11. The first few fuel ups got me only about 30.

  12. Glad to hear that it is getting better later.
    I looked at your Fuelly data and really there seems to be a change after 900 miles. The values go from 35 to 40 MPG (pitty that the data stops and there are no values after the PC-V installation though).

    I don't have any good figures before the PC-V installation so cannot say (sadly) if it increased the consumtion. It would be nice to test but the O2 sensors are in such a bad place that I wouldn't like to do that once again.

    So you are still having figures around 39-40 MPG with PC-V or is it just a "feeling"? I would like to go to a Dyno to get the mixture leaned up for low consumption highway cruising.

    Thank you for a very good blog!

  13. I use my trip odometer pretty religiously and do a quick calculation when I fill up. It's been pretty consistently around 40mpg.

    Glad you enjoy the blog, thanks for following.

  14. Something to add to this entry: at my last trackday the engine light was coming on after prolonged periods of full throttle (at the end of the front straight.) If the ignition was shut off and turned on again it would go away. I'm almost 100% certain it's the 23/24 02 sensor heat code. It didn't affect how the bike ran.

  15. Sensor heat code? So you have still the O2 sensors connected to the bike's ECU? My PC-V came with the O2-optimizer plugs which disconnect the sensors from bike. If you have the sensors still connected it could explain the low consumtion figures. To leave them on means normally lower consumtion but the PC-V starts working only on higher throttle openings.

  16. I have the optimizers connected but they don't properly "optimize". At high speeds (120mph+) with prolonged full-throttle the absence of the 02 sensors throws a fault code. It seems the VFR's ECU is anticipating a higher heat reading from the sensors under these conditions. It's a more sophisticated system than the optimizers were designed to deal with.

  17. I had my bike in Dyno yesterday. When we had the final runs with full power the engine light came on as you also noticed. It disappeared after the key was turned off and on. I suupose you don't have to worry about it (right?). I wouldn't like it to come on when driving on german autobahns thought (on hot summer day). I wouldn't like to reconnect the sensors as the PC-V support guys said that closed loop goes all the way to 60% throttle opening.

  18. Personally I'll just put up with an engine light going on once in a while rather than hook the 02 sensors back up. I don't think there's any harm being done. Besides, I tend to think that the 02 readings will have the ECU trying to "undo" what the PCV is doing and probably cause a surge while they fight over adding fuel and taking it away.

    The VFR is just a little too smart for Dynojet's little "optimizers"

  19. Hi Guys. I see your blogs are 3 years old and I'm not sure this was covered. I got my 2010 VFR12 about 6 months ago and just cant get over the 1st and 2nd gear torque hole. Did the PCV have this remedied? If not, are there alternatives?

  20. The PCV can't do anything to remedy the 1st and 2nd gear restrictions. You need to hack the gear position sensor wires like I did, or get a Bazzazz Buzz Bomb.