I am getting ready to get the exhaust done, but the facility wants to run 4" from the down pipe all the way back, and Ive been told to run from the turbo back by others. do ya think it would make a big diff ?
just looking for better egr's when pulling the camper
thanks for your time n trouble
brad

 

i just installed 4" mbrp stainless turbo back (downpipe is actually 3.5" not 4" unless you special order) and i noticed a difference. Prior to me installing the 4" I did a cat and muffler delete on my stock pipe and noticed zero difference accept the sound.. In theory I would think that it does you no good to run 4" and you keep the stock downpipe because your downpipe will always be the "choke point". It's like trying to shove 2lb of turd in a 1lb bag

 

thanks for the info that was what I was thinking too. prob just order it myself and get done, that way I know for sure what's under it thanks