If you want HP out of your saw then the exhaust has to be tuned, but with a big price. The pipe does not have to be very heavy, but bulky would be an understatement. Titanium would be completely out of the question for many reasons. For day to day use that does not sound like a great idea. For my purposes a enlargement of the muffler works well and will let the motor breath a little more easy with a cooler running motor. A tuned 2 stroke could easily produce 400% more HP than most standard saw engines, but with a bulky motor, less reliable, more heat and less longevity for why. It would be fun to grab a 40 HP saw with a good chipper chain on it and let the chip fly, but not for every day. I am surprised that there is not a push for 4 stroke saw motors with nice quiet mufflers and yes that would pretty much double the weight with only a 300% cost increase. Look at what happened to the off road industry in the past few years. Thanks