Naw if the engine is running the turbo is gettin oil has nothing to do with back pressure or having a muffler on it. I straight piped mine a month ago and love the way it sounds the only regret i have is that i didnt do it sooner.

 

A Cummins doesnt need any backpressure. They run best with a straightpipe. Will not hurt your turbo one bit.

Better look for another "consultant" too.

 

not true dyno proven that you will build boost faster and your motor will run mode efficient at lower RPM with some kind of baffle trapping 13% to 24% of exaust i have a straight pipe on mine with a baffle at a 10* angle 18in from the turbo and i can tell the difference between with and without

 

As I said.

 

your correct i didnt read your post

 

Ok, so maybe I was a little off there. But a straightpipe will not damage your turbo.

I had a 3" straightpipe - hated it.

Went to a 4" with the muffler - its still too loud.

 

I had my original exhaust on then I straight piped as soon as I bought the truck so I had 3 inch straight pipe. Just installed thursday 4 inch down pipe to 5 inch straight expandit exhaust and it made a notable difference and sounds great. My truck is only for work I don't drive it every day so I love the massive noise. Plus it spools faster and hits me 1-2 more psi boost I could theorize on it but I don't care it works great for me.

 

Straight piped my truck 2nd day i had it !! Best 30 dollar mod ive ever done .... help mileage too went from 15.6 to 17.2

 

yeah... about that.... id fire your "consultant". if that was true everyone with stacks (not to menstion hood stacks) would be eating turbos constantly.

 

so does pipe size from the turbo back make a diff. in sound like makes it lower or higher pitched. i have the stock downpipe back to the back of the cab going into 4inch and then 5inch stacks. I like the low deep tone that some of the cummins have but mine sounds more high sounding than most would 4inch all the way back change anything