I know Humanist/handschar has posted some great topics on R1b in the old DNA Forums. I can't seem to find a thread for this here, but thought it would be fitting to create one.
Over some of my (very basic) research, there are a couple sets of data I would like to share.
Currently 44% of the Kanem descent men belong to R1b1c-V88 - at least I am very certain this is the case. http://www.familytreedna.com/public/chad/default.aspx?section=ycolorized
A very brief overview of Kanem from Wikipedia's Kanem Bornu page.
"The origins of Kanem Empire are very unclear. Until today, historiographical debates oppose the followers of a foundation of Kanem-Bornu by populations from the ancient Near East and followers of a more local development. Some researches try to connect the creation of Kanem-Bornu with exodus from the collapsed Assyrian Empire c. 600 BC to the northeast of Lake Chad. The intensity of scholar discussions around this theory proves that the question haven't been solved yet, and we must be very cautious concerning early formation of Kanem-Bornu."
Of course this origin is up for discussion but I think we'd be hard pressed to consider a Central African origin of R1b - current evidence does point to somewhere in Asia, and I feel a back migration to Africa from the Levant is strong. Coupled with strong papers from Wood, this only supports the case further.
Second, doing a bit of research on YHRD it seems a small sample n=64 of Sudanese Bedouins might be 25% R1b1c. I can't seem to find the study that these are associated with, but it appears they likely belong to this group - a second possibly being T1. Unfortunately, DYS449 wasn't tested to make a stronger prediction.