ElfinS,
With all due respect, I'm not sure what sort of answer you expect. Only a select few of us run tuned exhausts and I don't know anyone running such of a 55cc jug except for me. What I've learned with my DLE55 is that the exhaust length can vary down to some minimum (around 29" for the 55, from exhaust flange to the reflection baffle in the pipe).....It can be longer by as much as 3" with no practical performance difference ...but not shorter than that.
If you are running a can, again I wouldn't shorten beyond that minimum.
Then again, since you have some practical issues to deal with, you may just have to try it on your own and see what you get. I'd bet no body has the exact answer you seek so why not develop it yourself.
ORIGINAL: ElfinSailor
@ WRK Thanks I really do understand that the preference is on the side of not trimming them down. There is no way they will fit in the current conformation as supplied. The exhaust would have to go through the landing gear. I spent a $100 a pop to have them custom bent to my parameters it took ten months to receive delivery and they are still little over an inch too long. They were supposed to bend them so the correct amount of tube would fit within the available geometry of the airplane. A 35% Dalton Extra 260 which has pretty much a standard spacial configuration seen in most IMAC 3D ships. My question is what is the downside if I trim them by an inch and an eight?