On both the R-50 we used to run and now the R-52 that we have, we run a 24 foot header. The OEM fin type spreader does an excellent job of spreading chaff in both wheat and soybeans. like someone else said, turn the wind up as high as possible and the "blast" will send it out the back. I have also found that if I run the fins in the most down position, it spreads over the area behind the best. It blasts it at the ground hard enough that it actually continues to swirl out to the width of the header. The key is the high wind velocity.