For my GRM Challenge turbo-1 swapped Rampage, I'm working on putting together a more 'real' exhaust for it (up until now it's either run with just the downpipe cut just before where the cat would have been or a 90-degree angle and straight pipe out under the side of the car to comply with the competition rules).

I grabbed one half of the exhaust system off of a newer V8 Ram truck from the junkyard which includes a muffler and good bit of 2.25" OD exhaust pipe. I've worked out, in general, how to use it to make the exhaust system but I'm curious about whether I can put the muffler where it looks most convenient- right after the downpipe- or whether I need to try and push it further back with a few feet of pipe between the downpipe and the muffler so that it doesn't interfere with the exhaust flow from the turbo.

Essentially, can I put the muffler where the cat was without messing with the turbo, or does it need to be further away (not going to be THAT far back though, will still be in the tunnel under the center of the truck). Thanks!