psycho...I think that is the real problem...we were racing on a very tight carpet track with little room to maneuver, so there were frequent tangles. I imagine it was the tie-ups that caused the cuts, which ended up becoming the chunks...my esperience with rubber tires is that they were a lot more forgiving in this area, but didnt have the traction...
The other thing I noticed running foams was I broke more front suspension parts...I attribute it to the wider tires, and more traction stressing the front end parts more...I dunno...maybe just a run of bad luck...
Anyway, thanks for the responses...