Just changed the mufflers on my 340 Sport. The Summit turbos that came with the exhaust kit sounded OK from outside the car but had terrible drone inside. I went with Dynomax Super Turbos, 14" long on a 2 1/2 inch system. I also added an H pipe, using the Summit H-pipe kit. BTW, that kit is great if anyone wants to add an H-pipe. Here's the result at idle in the cold, humid air.
