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Old 09-29-2013, 05:23 AM   #505
ebrabaek OP
Beastly Adventurer
Joined: Jan 2010
Location: Grand Valley, Colorado
Oddometer: 4,874
Originally Posted by roger 04 rt View Post
I'm not singling out the dyno operators, who I have no reason to mistrust. All I'm commenting on is the AFR test method. The tailpipe AFR probes can't do a good job at the start of an short inertial dyno burst. The exhaust flow is low and they are too near fresh air. The engines would likely stall if the AFRs were that high.

The better test method is an upstream probe such as an innovate (or other) LM-1, LC-1 or LC-2. (I'm not basing any of these AFR comments on GS-911 data.)

Think of It this way: you're running down the road at 2000 rpm in 4th gear. Your stock bike would be running a Closed Loop AFR of 14.7:1. At that point you crank the throttle to WOT. The BMSK goes Open Loop instantly and changes fueling (much faster than a tailpipe probe can respond). It picks its new fueling point based on TPS of 100% and RPM 2000. I would estimate that point is 12.8-13.2:1, and it adds an acceleration enrichment. I have measured this on F800S, R1200GS, R1150, and R1100. They all instantly go to an AFR between 12:1 and 12.8:1 approximately.

This is why I say that those high AFR numbers are in error.

I think I will call this a difference of opinion then..... . The 8gs does exactly have issues with a terrible throttle response from idle through a few K rpms. What I am seeing, I conclude is consistent with a roll of from a very high AFR, to a lower AFR. I will say this Roger...... Reading back through this thread, I think it is fantastic that we have all been able to express our different opinions, and do so in a civil matter, with all of us behaving like adults, and no one getting upset. I think this thread represent the best of ADVR culture, in a great collective way. As we have different opinions, none are rejected, and bashed, and for the great contribution, Roger, I commend you. You could have bailed long time ago, but are still offering your opinion. All too many times do you see a thread going to hell, because of those opinions, and peoples egos, as their bikes are being picked on. I would like to thank all who have been contributing to this thread, and has done so in a civil matter......

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