Non mandrel bent exhaust?

Prine, thanks for the response. Our motor should make close to 400hp off the spray and then we are planning a 100 shot. We should be very close to 500hp on the bottle. I know we want/need 2 1/2 mandrel bent at a minimum. My question is what is the flow difference between 2 1/2" mandrel and a 3" regular bend?