Camel's K8

[Camel]

Mountin†and wirinâ€

Time was fast getting away on me so I decided Iâ€d mount the Tech Edge 3B1 unit (which houses the data logger and heater control) and the Tech Edge LDO2 LED display unit so I could at least see if the system was working. Rather than go with rubber dampened bolted mounts I took the quick and more effective self-adhesive-backed Velcro approach. This way the data logger fits neatly in the Busaâ€s cavernous underseat storage compartment and may be quickly repositioned or removed to gain access to wires, thermocouples, etc.



The display fits on the top triple clamp, out of the way but still visible. Its cushioned against vibration and easily removable thanks to the modern miracle of Velcro.

Everything fits together well, the wideband plugs in and is secured by a knurled nut (the silvery knurled thingy at the top of the image below). Power plug clips in with a satisfying ‘snick†sound (the white plastic thingy below the silvery knurled jobby) and the display unit plugs in on the front plate of the datalogger via a RJ45 plug.



Once wired up I calibrated the datalogger by first removing the wideband sensor from the exhaust and exposing it to ‘free air†i.e. uncontaminated breathable air with an oxygen concentration of 21%. After powering up the datalogger I wait a couple of minutes while the sensor reaches operating temperature (heater signal and power supplied via the datalogger) all the while making sure I donâ€t let my rancid CO2 and garlic contaminated breath foul the sensorâ€s readings. The sensor canâ€t be moved while calibrating so it needs to be rested on something clean. Preferably something that wonâ€t be melted by the heat.

Once heated I hold the data-logging button in for at least four seconds and then watch the red LED (see image above) as it merrily flashes away for about 15 seconds before sending out a frantic burst of six flashes and returning to steady state. Turn the unit off, let the sensor cool, screw it back into the exhaust then plug ‘n†play.

Now letâ€s ride! Before starting the bike I turn the key to ‘on†and let the LSU wideband sensor heater warm up the tip. The display unit gives me the good word (heat) and then indicates ‘lean†when ready.



Start the engine. Let it warm up. Then while idling the display returns an air/fuel ratio (AFR) of around 12.6:1.



This ties in well with PetriKâ€s findings, i.e. the Gen II HO2S has a window of operation as follows:

Throttle Position 1-9%
Coolant Temperature greater than 80C
Intake Air Pressure 6-60 units (as per EE2)
4000-6000 RPM

Then I rode the bike, keeping in mind that I still have the PAIR valve operating just to see what it would do. Sure enough, it works almost all the time; I observed readings between 18:1 and 29:1. So I turned around (I live in excellent scratching territory ) hammered it home, removed the airbox and shoved a marble into the hose between the airbox and PAIR valve (a green marble) to stop it giving me false readings. Note that the PAIR valve needs to be kept in place or a resistor placed inline otherwise you get a fault code. In time Iâ€ll use EE2 to program a shift kit via the PAIR valve connections.



Now with the PAIR disabled and the HO2S still connected I went for a lovely little jaunt through the hills. Hmmm. That HO2S is bloody effective. Other than when cranking the throttle the AFR clings stubbornly to 14.7:1 (stoichiometric rate). Sure it varies, but not much more either side of 14.82:1 or 14.6:1.



So, after pulling up in a sun-dappled forest glade peppered with a splendid display of spring flowers (you can almost see Bambi frolicking there canâ€t you?) I disconnected the Busaâ€s standard HO2S. Turned ignition on, saw fault code, then turned off and back on. No fault code, (but we all know itâ€s there, donâ€t we?) Wait for sensor to heat, then kick her in the guts (metaphorically speaking) and tootle off.

At idle, no change to AFR. Accelerate, and depending on throttle position, revs, etc the AFR can jump as high as 11.3:1! At cruise, where previously the bike ran in the HO2S window, (and therefore returned the stoichiometric rate of 14.7:1) the AFR is now in the mid 12â€s. Hmm, thatâ€s rich. I donâ€t reckon thatâ€s good for a bike that spends most of its time cruising. Thatâ€ll eventually root the LSU sensor and the catalytic converter. Not a drama now, but could be when/if they make downstream oxy sensors mandatory on bikes. These are used by the ECU to determine if the catalytic converters have passed their use-by date, or have been tampered with. If yes, the ECU returns a fault code and the bike goes into limp-home mode. Well if it happens its in the future and we can deal with it then.

So what have I learned to date?

Well keep in mind that I havenâ€t actually logged data yet. Iâ€ve been sneaking glimpses of the display unit while riding. While accurate I still want a data log where I can relate AFR to a host of other variables.

What I have learned though is that the PAIR valve and HO2S do a fantastic job in reducing hydrocarbon emissions when working in conjunction with the catalytic converters. Also, I suspect that without the HO2S fitted your fuel usage would jump significantly (if doing normal riding cruising). Iâ€ll be logging this to gain some real-world information that will be useful to the 98% of riders who donâ€t drag race their Busas.

For performance tuning I believe the HO2S shouldnâ€t be scuttled entirely. Sure it will fight your map changes, but only in the HO2S window, i.e. when cruising at legal speeds. I think there is a lot of advantage to be gained by lowering the top end of the HO2S window from 6000 rpm back to the Gen I cap of 4800 rpm or even lower. I donâ€t think youâ€d disable the RPM range altogether as it would create havoc when you were running at high RPM at part throttle positions. If you could alter the rpm range of the HO2S window the rider would know when the richer ‘performance†map slips in and can keep the revs above that area to maintain max power without having the stoich-to-rich transition lag occurring. The skilled tuner could also set the top HO2S limit and then tailor the fuel map to smooth the transition further. That way I reckon you could get the best of both worlds, better performance while still retaining good fuel economy when cruising in the HO2S window.

Camel


In the next episode..... tapping into what's going on, analogue, digital and thermocouples...