I've been interested to make some measurements of the effects of R1200 injectors on an R1100 . A friend with an R1100RT, who has installed R1200 Injectors, and has an LC-1 Wideband O2 agreed to make some measurements of the AFR effects of the new injectors. He completed the first test which was to reset the Motronic, clear all adaptives, and then start the engine cold and let it idle until warm up. A cold start after reset allows us to see the AFR of the engine before the Motronic has made any compensation. By comparing that plot, to a plot made with the old injectors (which is in my Wideband O2 research thread) we can get a picture of how much richer the R1200 Injectors run until Motronic adaptation takes place.
A stock R1100RT, on a cold day adds enough fuel to bring the AFR to about 12.8:1 during the warm up period before closed loop (see:
http://advrider.com/index.php?threa...or-project-and-af-xied-for-bmw.749080/page-17). From experience with R1100s and R1150s, the cold start enrichment runs in the 10-15% range.
Now take a look below, at the post-reset, cold-start enrichment immediately after installing the new R1200 Injector kit. The AFR is about 11.35:1, which is a 23% enrichment. What this means, as I pointed out earlier in the thread, is that the R1200 injectors are temporarily adding twice as much enrichment, before the Motronic dials it back to the normal 10-15% through its adaptation process.
Another way to determine how much fuel the R1200 injectors add prior to Motronic adaptation is too measure how accurately it switches from cold-start enrichment to Closed Loop operation. When the adaptations have been fully developed, the Motronic can accurately calculate how much fuel is needed to achieve 14.7:1 at idle. Therefore when it leave enrichment mode, it is en closed loop in a matter of seconds. Looking at the chart below, you can see that it takes the Motronic about 12 seconds to search for and then calculate a short term trim (adaptation) that allows for Closed Loop operation at 14.7:1. The first attempt by the Motronic only seems to get the AFR to about 12.2:1 versus the target of 14.7. That suggests that there is about 17% more fuel being injected due to the R1200 injector's faster turn on time.
Double checking that, the normal idle pulse is about 2mS of which 1 mS is the turn on/turn off time, so about 1 mS of fuel. 17% more fuel would mean the turn on/off times are 0.17 mS faster on the R1200 injector compared to the R1100 injector. This figure seems reasonable.
So a bottom line, looking at the measurements of cold-start enrichment and then the converge-to-Closed-Loop operation, is the first time you start your bike and for the first few rides, there will be a lot of extra fuel at startup and during acceleration.
Next, after a couple weeks of riding, we'll take a look at the same numbers again.
