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[hrdtail78]

Post 41 has data also.

Comparing a broad band sensor line to a narrow band output is kind of like.  Measuring with a mic, marking with a crayon, and cutting with a chain saw.  Who really thinks that a harley combustion chamber is that stable that fuel delivery is going to be a constant from back to back to back pulls?

[Buckeye_Tuning]

OK, using the AFR meter on the dyno, I adjusted the VEs to output 13.0 AFR.  The above is the voltage for 13.0.   I am working the rear cylinder for this.

Now...  I should be able to use data master and fill cells out, using this voltage and lets see how it sniffs tomorrow.

[Steve Cole]

Before you say this is it, how close is it to 13.0. You should be able to hold it on the brake and repeat the test several times and I am willing to bet there will be movement in the dyno AFR number so you need to give the measured range NOT 13.0 as they are just not that good. If it's like everyone else that's done it the range is about a 0.8 AFR range.

[Buckeye_Tuning]

I have another bike on its way, so I took that bike off of the wheel.

I WAS on the brake and holding around 60MAP and 3k rpms., as that is where I was adjusting.  The AFR meter on the dyno was fluctuating between 13.0 and 13.1 with barely the majority of the time at 13.0.

I just wished for a 'starting point' that wasn't flying all around.

So... I shouldn't try to target that 920MV when doing sweeps?  I thought that should be able to get me like 12.5 to 13.5 all around or even a bit tighter?
 

[FLTRI]

Why don't you target the 920mv and see what that produces for resultant AFR?
No harm trying it.
Bob

[Buckeye_Tuning]

I agree, Bob.  It's why I did it, to look see.

[Hilly13]

My word there is some foxing going on here 
Great thread 

[Steve Cole]

Without testing no one is going to know. I just want to make sure that people understand a variation is a normal thing. The range of the variation is a major something, that needs to be defined and understood with ANY O2 system. Once you get enough information and the range is defined it will make more sense I think.

[FLTRI]

Hey Buckeye! How'd your voltage vs AFR testing come out?
Seems we are getting to an agreement here that NBO2 voltage can be relied upon to target a given AFR?
Hope to see and hear your results soon!!
Bob
PS - Thanks again to Mayor for supplying his results.

[mayor]

I hope to be able to provide some '09 DBW 205 calibration data results here sometime soon.  I'm running closed loop on that bike, so I'll likely drill my headpipes for the herko blocks to sample.  I think that will be better for this test than a sniffer tube up the pipe.  Which just kind of sounds dirty anyway.  The weather hasn't exactly cooperated lately, and I have a road trip coming up week after next, so it may be a few weeks until I'm on the drum again.

[Steve Cole]

I do not believe drilling for blocks is any better or worse than a sniffer tube. At least with a tube you can move it around if you determine that it is not sampling correctly. With blocks your going to have to drill and plug, drill and plug...........

[mayor]

you don't think lag comes into play because of the hose length? 

I've still got the factory non-cat '09 headpipe on that bike, so I'm not too concerned with drilling and plugging. 

[hogasm]

I do not believe drilling for blocks is any better or worse than a sniffer tube. At least with a tube you can move it around if you determine that it is not sampling correctly. With blocks your going to have to drill and plug, drill and plug...........

Steve how can you install a sniffer into the rear pipe if a 2 into 1 pipe is used? Most tuners I have watched only tune the front cylinder with the sniffer and guess to the rear
Why not get the readings from the 02 sensors so both cylinders can be read?

[joe_lyons50023]

Steve how can you install a sniffer into the rear pipe if a 2 into 1 pipe is used? Most tuners I have watched only tune the front cylinder with the sniffer and guess to the rear
Why not get the readings from the 02 sensors so both cylinders can be read?

I use a flash light and prebend  the copper tube up to help me.  I know it was always real easy to tell where you were at when using power commander as you could just adjust fuel and see what the readings did.

[Steve Cole]

you don't think lag comes into play because of the hose length? 

I've still got the factory non-cat '09 headpipe on that bike, so I'm not too concerned with drilling and plugging. 

Yes, lag is a part of the issue but the blocks cause there own ones too. Look at the exhaust flow and how the blocks go into the pipe. 90 deg to flow, Low speed is the area where you can see wrong readings with blocks due to how they sample, so nothing comes without it's own set of issues and one needs to be smart enough to see them then work around those issues. Just remember you cannot do anything about the sample time of the sensor itself so if you can get the exhaust gas there at least some amount of time quicker than that, it becomes the limiting factor. I tested the block idea long before Herko copied the ones from the guy in the bay area.

Look, there is more than one way to skin the cat so to speak but each has issues that you need to be aware of. As far as a 2:1 goes a little bending on the end of the sample tube will get you up the rear cylinder just fine if you pay attention. While I use our in house stuff 95% of the time and they always have the bungs properly installed it does make my life a little easier than the average tuner who has to deal with what comes in the door. There is no full proof way and you have to do the best you can within those limits.