ive been lookin through here and some of u guys have a straight pipe on ur trucks and alsosomethin about no ring?? i have a 4" magnaflow on my truck now but i want it to be a little louder, i was thinking about cutting the muffler off and putting a pipe in its place but does a diesel need back pressure? and what is this ring everyone is talking about?

 

I can't say as I know a diesel need's back pressure or not.
But I myself am runnin straight pipes and so are several of my friends and we
have never had a problem. As for the ring removal your probably thinkin of the turbo silencer ring removal.
It's not a performance mod it just makes the sound of the turbo spooling up louder.
U can read about the removalprocess in the DIY section at the top of the Cummins page.

 

diesels don't need back pressure. Infact back pressure slows turbo spooling

 

How does a straight pipe affect performance like mpg or torque?

 

I didnt notice any power/mpg loss or gain.

 

pretty much unnoticeable. I think I lost somewhere around 0.07 mpg.

 

It's supposed to help your mpg but that's what they say about everything. I think they're lying I should be getting 30mpg by now

 

Opening up the exhaust and intake will drop your MPG slightly. Go figure, you are getting in and moving out more air......more air = more fuel.

As for the power, I noticed no noticeable change down low. The turbo definitely spools quicker and the top end is where you see big improvement. Over 2500 RPM's, it turns into a rocket.

The biggest improvement, and the one I was looking for, was the EGT drop. At idle, I'm down about 50 - 75*. At cruising speeds, I'm between 100 - 150 lower. And I can push the higher settings on my Juice without bouncing off of my EGT limiter.

 

I've heard alot about lowering EGTs'. What is the benefit? I'm new to diesels and am trying to get as much knowledge as I can about my truck.

 

the lower your egt's the less of a chance you have of torching a valve or melting the turbo.

when you add power boxes and the such you are adding more fuel into the cylinders, thus things will run hotter. one way of reducing EGT's is by yanking out the stok muffler. other ways if your EGT's are getting to high is to install an aftermarket turbo that flows more air, water meth injection, propane, nitrous, bigger intercooler, or even twin turbo's.