[AussieDave]

Whilst looking through the hitchcocks catalogue I noticed that they stock replacement valves for the efi motor that have a thinner profile . I am wondering , what sort performance improvement these would achieve . I also noticed some very positive testimonials regarding the use of the power commander  both with and with out dyno tuning. Can anyone share their  experience of these ?

[Roeland]

So far I changed to:

-    Goldstar exhaust with larger diameter front pipe
-   Power Commander with Autotune
-   19 teeth sprocket
-   K&N airfilter
-   Separate Crankcase breather filter
-   535 cc Wosner piston
-   Pulsed plasma nitride treated valves

I also have send a cylinder head for further modifications to ACE in the states but that did not arrive there yet. The idea is to flow the entire head, make special high lift rocker arms, etc... the end result could be a 40 HP bullet.

The Power Commander I installed was the previous generation hybrid unit that was originally designed for a 400cc ATV Suzuki and does not have the option to change the ignition settings as the new unit can do.  The initial map supplied was not to my satisfaction; a lot of back firing, etc... Bear in mind that the RE supplied to the UK are different than the ones we have here in South Africa. We do not have catalytic convertors, the bikes are all twin spark and there's a PAV valve, which basically pumps some clean air in the exhaust to dilute the mixture when it leaves the exhaust.

I entirely removed the PAV valve and bolted the hole in the cylinder head. I also disconnected the crankcase breather from the airfilter as I did not want any dirty air to end up in the injection system. The next step was to install an Autotune unit which enable me to adjust my own maps as the system basically reads the AFR as it leaves the cylinder head. There was a vast improvement, but still not to my satisfaction as I still encountered numerous backfires on hard de-acceleration. I then proceeded to install a speed sensor on the speedometer cable, connected the 5 volt square wave signal to the Power Commander unit and calibrated the speed to the rpm's and gear positions.  This was rather difficult because the only way this could be done was with a laptop strapped to the petrol thank at a speed of at least 40km per hour plus in each gear and then with one hitting the enter button whilst on the move. The PC also allows you to go beyond the rev limit although I could not get my bike to rev faster than 5850 rpm.

All is working very well at present with a separate AFR and Autotune map for each gear. The only thing I could not put my finger on yet is as to why after the peak torque the Autotune wants to decrease the values in the AFR dramatically.  In some instances by  -50%.  I would have expected the factory ECU to take care of this unless it perhaps is set to be very rich after peak torque.

On overall with all the mods there is reasonable amount of power increase, especially torque - which I was looking for since I travel most time with a pillion. Currently top speed has not increase dramatically. With pillion and saddle bags we did 145 kmph on the speedo and I convinced she could reach 150 kmph if I was not so scared at the relative instability of the bike at these speeds - something I'm still working on.

I'm not sure if the pulsed plasma nitride treated valves alone  would give any significant performance improvement as I installed stimultaniously with the larger piston.

Ps. Als please note that the Autotune will get confused if your bike burns oil. I had this with my previous 500 cc piston and eventually I ended up with too little petrol in the mixture.

[ace.cafe]

It states that these valves are "simple replacement", so they are the same stem diameter as the stock ones. The valve heads may be shaped differently than stock, but that doesn't always mean that they will flow better, although they might. If they developed this shape on the flow bench, then they would flow better with the standard port and valve seat shape that is in the stock bike.

Regarding "slimmer", that usually refers to a slimmer stem, and a slimmer stem offers less blockage of the flow because it takes up slightly less space in the port. However a slimmer valve stem requires different valve guides to fit it, so it wouldn't be as "simple" a replacement as just slipping the new valve into the existing valve guide.

The plasma nitriding is a nice finish for the valve stem that is essentially a harder surface treatment. Not really a performance improvement, but it might possibly provide some improvement of wear in the guide if it is highly polished. Generally, it is the bronze guides that wear out, not the valve stem.

[gashousegorilla]

Whilst looking through the hitchcocks catalogue I noticed that they stock replacement valves for the efi motor that have a thinner profile . I am wondering , what sort performance improvement these would achieve . I also noticed some very positive testimonials regarding the use of the power commander  both with and with out dyno tuning. Can anyone share their  experience of these ?

   I use a power commander PC-V  and am very happy with it as well.  Actually I have used two versions of it.  Both work very well.  The First version I tried, like Roland, is actually for a LTR 450 Quad.  Which will only allow you to make fuel adjustments, not timing. And it Does not allow you to increase the rev limiter.  I also had to make a change on the plug for the O2 sensor "fooler".

   I'm presently using the latest version of the PC-V , that Dynojet put out for all the UCE models.  It allows fuel AND ignition adjustments. As well as a rev extend, to increase your limiter if you so choose or need to.  It comes with a base MAP, for a stock, or near stock bike.... Which can be modified and worked off of . Should you need to, for any special changes you made to your bike. It's a pretty simple install... just plug in the sensors. And for a stock bike, or one with a after market silencer, it just a matter of plugging the devise into you PC or laptop and hit "RUN MAP" , and your done.

  As far as the Valves go... I'm assuming they also have a "3 or 5 angle" grind on the valves to improve flow.   That was done on my stock valves to good effect.

[Roeland]

Hi,
The old version of the PC5 does allow for increasing the rev limit if you upgrade the firmware to the new version. That is what I did. Regards

[AussieDave]

Thanks guys, for your most informative and very interesting replies. This provides much food for thought. Cheers

[singhg5]

   I also had to make a change on the plug for the O2 sensor "fooler".
 
  I'm presently using the latest version of the PC-V , that Dynojet put out for all the UCE models.  It allows fuel AND ignition adjustments. As well as a rev extend, to increase your limiter if you so choose or need to. 

Does the latest version of power commander V connect to oxygen sensor to get feedback from exhaust to adjust AFR ?

Or the maps are based exclusively on the throttle position and engine RPM ?

[gashousegorilla]

Does the latest version of power commander V connect to oxygen sensor to get feedback from exhaust to adjust AFR ?

Or the maps are based exclusively on the throttle position and engine RPM ?

  No Singh. The latest version does not connect to the stock narrow band O2 sensor, it also has a "Fooler" that plugs into the stock harness. It basically just "Tricks" the ECU into thinking it is there.  Then the MAPs , fuel and ignition, are created on a Dyno, with a tailpipe sniffer that reads AFR's.  The AFR numbers are changed by the operator of the Dyno, .... Usually between 13.2 :1 to 13.7 :1 based on the results he sees as far as HP and torque. He can also advance or retard the timing based on the information he is getting from the Dyno.  All of this is done across the throttle and RPM range. 

  As you know, the stock O2 sensor is more switch like.  And does it's best to keep the AFR at stoichiometric, which is 14.7:1 . This is a good mixture for emisions purposes , by not for power.  So as we make modest intake and exhaust changes on our bikes, that the stock ECU can "Cope with" .  They may help some.... BUT the O2 sensor and ECU are  still trying to keep that 14.7: 1 AFR.  With that in mind when a change is made to the intake and exhaust, one should be careful about how modest that change is.  Because if it's not THAT modest, you may at least negatively effect performance , or you could go dangerously lean in some area's of the RPM  Range.   

  Also, the ECU is NOT always in closed loop, with the O2 sensor keeping the mix at Stoich. It's in closed loop at Idle, after the O2 sensor heats up.  It's comes out of closed loop at maybe 20-30 % throttle opening. So on hard acceleration..... your not in closed loop.  Generally, you are in closed loop when cruising.  When your out of closed loop in those situations... the ECU is relying on the inputs from the MAP, TPS, Temp sensors etc. And look up tables in the ECU to compensate. If one of those look up tables that the ECU can choose from doesn't match, or is not programmed into the ECU for the change you have made........ It don't work out too well.

Hi,
The old version of the PC5 does allow for increasing the rev limit if you upgrade the firmware to the new version. That is what I did. Regards

   Interesting Roland, what is the update ? Do they add a wire to the Ignition Coil ?

[gashousegorilla]

 Here Singh, a good video on the Power Commander O2 sensor eliminator, and behavior of a Narrow band O2 sensor.....

http://www.youtube.com/watch?v=Nwgy2F0E-30

[singhg5]

Here Singh, a good video on the Power Commander O2 sensor eliminator, and behavior of a Narrow band O2 sensor.....

http://www.youtube.com/watch?v=Nwgy2F0E-30

I liked it  !  Youtube is amazing for sharing technology.

Coming back to AFR -

On my stock G5 dyno test, throughout the entire test range of engine RPM from say 2K to max 5.3K the AFR was between 12.4 to 13.4 which is richer than stoichiometric value of 14.7. This suggests that the bike was not running lean, nor running in closed loop, but more like hard acceleration when ECU is selecting one of its stored maps based on MAP, throttle position and RPM of engine at any moment and oxygen sensor is not altering the selection of ECU map.

Based on these AFR results, it seems Keihin ECU maps are set to give maximum power on acceleration. For a stock bike there is no need of Dynojet power commander.
 
However to gain real power, bigger changes are required in valves, cam, piston size, compression, exhaust and intake which Keihin ECU maps are not designed to fully utilize and handle. Then Dynojet power commander piggy back system will be helpful to gain maximum engine power. Unless big changes are made, power commander by itself will not really improve the performance of engine.

Small changes in exhaust can be handled by Keihin ECU maps with its O2 sensor.

Has anyone tried Dynojet PC on a stock bike without changing anything and found any difference in its performance ?

[gashousegorilla]

  Yup, I agree Singh.  I wouldn't waste the money on a PC-V  or any other devise for that matter if I intended to keep the bike stock... In the right tuners hands, or with a good MAP ? .... Ahhh, you might pick up a little better throttle response ?  Maybe ?.   Maybe half a horse .... or 1 ft lbs of torque ?   

   Personally, I think the starting point at which I would consider one would be if I where to really free up the intake and exhaust. I say the intake, because of the MAP sensor on the Throttle body.  The ECU is really looking for specific Voltage readings from it, based on manifold pressure. And that is determined by the design of the intake and filter. .... Cams will effect this as well !  Any change in the manifold pressure effects the voltage that the ECU sees, which effects fuel and timing.


 And BTW, your AFR's look pretty rich Singh !  No need for one with you!  

 Also the stock AFR's we see are based largely on what the TPS is set at.  Higher voltage is richer, lower voltage is leaner, and that's across the range. I bet yours is in the neighborhood of .6 or so ?  Stock pipe and intake ?   The tuner at the Dyno, will also calibrate the TPS setting on his software, and use it as a base to work with.  So it's important not to mess with the TPS setting, on the PC-V software or the TPS...... after it's been Tuned or MAPed on the dyno.

[Roeland]

gashousegorilla, I did installed a firmware update via the PCV screen interface screen under power commander tools but I'm not totally sure this freed the rev extender or the fact that I also initially installed the map for the new PC5 with ignition interface. The old PC5 does not connect to the ignition anywhere but you can see the empty ignition tables on the interface screen if you so desire. Yesterday I enriched the AFR values between 13.6 and 12.5 and felt a dramatic improvement today on a 150km ride. - especially at open throttle.

[gashousegorilla]

gashousegorilla, I did installed a firmware update via the PCV screen interface screen under power commander tools but I'm not totally sure this freed the rev extender or the fact that I also initially installed the map for the new PC5 with ignition interface. The old PC5 does not connect to the ignition anywhere but you can see the empty ignition tables on the interface screen if you so desire. Yesterday I enriched the AFR values between 13.6 and 12.5 and felt a dramatic improvement today on a 150km ride. - especially at open throttle.

  Good deal Roeland. Yes, I have a few area's that I'm down into the upper 12's as well.  Ummmm, not sure either about how you were able to rev extend..... But my guess is the installation of the ignition interface MAP.... I THINK ?   Not sure...... But I assume Dynojet is rev extending with the ignition, hence the coil hook ups.  Maybe seeing that you don't have any, it defaults to a 500 rpm increase ?   Just a guess though.

  With the new version, you can rev extend 500 RPM's by entering a code provided by Dynojet in the rev extend box. So your new red line of 5850 makes sense to me.


   On second thought, remembering and closer examination Roland. The new version ALSO  ties into the pulsar coil at the rotor, as well as the ignition coil.  So I believe that yes..... they must be controlling ignition and rev extend through the ignition and pulsar coils.  And I believe that is how fuel control suppliers do it.. We had a Email conversation with Race Dynamics, and their idea or plan for extending or eliminating the rev limiter . Was to grind off one of the nodules on the rotor .

  Is it possible Roland, that your ECU has always allowed you to rev it to 5850 ?  Perhaps because it is an IDM ECU ?   I think we had one of our members...Bare ?... Rev it up that high on a Dyno pull.  But most seem to be a little shy of the claimed 5500 RPM limit.







 

[Roeland]

Hi,

To be honest I cannot remember the rev limiter ever kicking in and I often take it flat out at high revs through each gear. On the power commander interface just above where you supposed to enter the code to increase the revs my unit indicates a current rev limit of over 10000 (can't remeber the exact number). When I initially got the unit from Hitchcocks the map was populated to 10750 revs. I'm not sure why - I populated my new maps to 6000 revs. At either 10750 or 6000 revs the Autotune does make adjustments over both entire ranges. Does not make sense to me as the bike can not rev that high but perhaps this has something to do with it?

[ace.cafe]

Hi,

To be honest I cannot remember the rev limiter ever kicking in and I often take it flat out at high revs through each gear. On the power commander interface just above where you supposed to enter the code to increase the revs my unit indicates a current rev limit of over 10000 (can't remeber the exact number). When I initially got the unit from Hitchcocks the map was populated to 10750 revs. I'm not sure why - I populated my new maps to 6000 revs. At either 10750 or 6000 revs the Autotune does make adjustments over both entire ranges. Does not make sense to me as the bike can not rev that high but perhaps this has something to do with it?

It's possible that the map file was copied from another engine application with a higher revving engine.
Regarding the rev limiter rpm, I have read various numbers from different people, ranging from about 5400-5600 rpm, if memory serves me well. I think it is supposed to be spec'd at 5500 rpm, from what I have read about it.  It's good that it can now be moved out of the way, for performance-seeking riders.