Here is a drawing of the inside http://www.dieselpowerproducts.com/aeroturbine The 4040L is exactly the same thing with a 4" perforated resonator at the inlet. We have not seen any evidence that one is more restrictive than the other and either one will lower EGTs more than just the 4" exhaust.Hokey said:Curious about these aeroturbines- is there a cutaway view of these anywhere? like to see what is inside and what the difference in the 4040 and 4040L is and wonder how restrictive the two are or are not... anybody know??
thanks