The Slimline Pitts muffler on my G26 cuts 500 rpm from the same engine with no muffler at all...A standard Abell muffler loses only 200 rpm, but is louder..There's a fine line between size and power..Maybe Slimline will design a new muffler that would be tuned, making the engine even better..Still waiting for my very own DA50..Maybe next week....