Happy holidays to all. I have a question regarding the crossover pipe on the LLY. I was in a shop today looking at exhausts and one guy says to remove all the pipe from the turbo back and install new 4" with a 5" tip. I go to another shop and they said the LLY has a 4" downpipe from the turbo and no need to buy another pipe, just go from the cat back. They told me when they did the tests, there was no difference in performance removing the stock pipe and cat or leaving the cat there and adding new pipe to the tail. Any comments are greatly appreciated. Keep up the good work on this site, it is great.:)

The downpipe didn't look 4" to me. I believe it's 3.5"

Every time a see an ad for a "turbo back" system, when I question them, it's actually and intermediate pipe back system. I haven't seen an aftermarket downpipe yet.

Nope, that pipe is about 3.4"....no where near 4"....that and that stupid converter is in there too with those funky bends......It does look nice laying on my shop floor though ):h