I was watching NHRA on tv the other day and the anouncer claimed that the downforce created by the upswept headers was equivilent to 1000 lbf. Pretty interesting to me- you have to be either moving a lot of gas or moving it pretty quickly to get that much force. (conservation of linear momentum eqn). Not to mention they are swept at an angle so a component of that force is actually thrust. I'm sure its important too because the foils won't be working until its up to speed- this downforce occurs at launch, in my thinking one of the most critical times. I wonder if someone put a C/D nozzle on each of the stacks to choke them how much downforce/thrust could be gained. It would come as a tradeoff for engine volumetric efficiency though.
