5 Inch Straight Pipe 6 7 Cummins

Which 5-Inch Exhaust Fits Your 6.7L Cummins?

Your model year decides which pipe bolts up. The 5-inch DPF delete fits a 2008 through 2012 Ram and runs $849.00 to $1029.00. The 5-inch full exhaust fits a 2013 through 2018 Ram with the 6.7L Cummins at $799.00 to $869.00. The 4-inch system covers those same years from $699.00 to $775.00. A second 4-inch system covers 2019 through 2024 from $699.00 to $824.00.

Get the bracket wrong and you pay freight both ways. Get it right and the rest of the job is bolt-on.

Four listings. Three brackets. Two diameters. That is the whole decision, and everything below is just how to make it.

Reading the model year off your own truck

Which bracket does your truck sit in? Two minutes at the door jamb sticker settles it, and it is the cheapest two minutes in this entire build.

The 5" Exhaust DPF Delete fits the 2008, 2009, 2010, 2011 and 2012 Ram with the Cummins 6.7L. That is the older bracket, and it stops where it stops.

The 5" Full Exhaust System fits the 2013, 2014, 2015, 2016, 2017 and 2018 Ram with the Cummins 6.7L. Model year and build date are not the same thing. Read the sticker, not the calendar.

Where the 5-inch listings stop

Here's the thing — that pipe does not cover every year of this engine.

The 4" Full Exhaust System fits the 2013 through 2018 Ram with the Cummins 6.7L. The 4" Full Exhaust System for 2019-2024 fits the 2019 through 2024 Ram with the Cummins 6.7L. So the newer trucks run the smaller diameter.

The 6.7-liter engine became available in Dodge Ram 2500 and 3500 models beginning January 2007.^[1] That is a long run for one engine family, and the hardware behind it changed more than once along the way. Ordering across a bracket is how a good Saturday turns into a return label.

Cab and box length, and what it does not change

Crew cab, mega cab, short box, long box. None of it moves you into a different listing.

It's built from high-quality aluminized steel with OEM-style hangers and clamps, so it bolts to factory locations across all cab and box lengths — no cutting, no welding. What your cab and box do change is the tail end of the job, and that comes later. The bracket is still the bracket.

What Does a 5-Inch Straight Pipe Actually Replace?

A DPF/CAT delete pipe is not a full exhaust system, and it replaces only the section of the factory exhaust that contains the emissions parts. The rest of the factory exhaust stays where it is. One 5-inch pipe fits the 2007.5-2012 Ram. The other 5-inch pipe fits the 2013-2018 Ram.

We get it — under a truck on jack stands, one length of pipe looks a lot like another. It is worth knowing exactly what you are unbolting before the first clamp comes loose.

The two barrel-shaped parts under the middle of the truck

Get under there with a light and you can put a hand on the parts in question.

Those are the two barrel shaped parts in your exhaust near the middle of your truck. Everything forward of them stays. Everything behind them stays. So the job is smaller than it sounds — one section out, one section in, and the rest of the truck never knows.

Section pipe versus full system

A lot of guys assume a delete pipe and a full exhaust are the same purchase. They are not, and the difference shows up on the invoice.

This exhaust runs downpipe-back, replacing the DPF and CAT with a straight, free-flowing 5" pipe. That is the older bracket, picked up one joint back from the turbo.

This 5" pipe runs straight from the turbocharger outlet, replacing the factory DPF, CAT, and every restrictive mid-pipe section. Which one you want depends on how much factory pipe you are willing to leave under the truck.

Where the joints are, front and back

Two joints. That is what you are undoing, and both have been sitting in grime and salt for a decade.

The front end of the delete pipe connects to your down-pipe and the tail end of the delete pipe connects to the tail pipe, just before the bend over the rear axle. Soak both the night before. Ten minutes with penetrating oil beats an hour with a cutoff wheel.

Why Do Owners Move Up to a 5-Inch Pipe?

The 5" diameter flows bigger than a 4" for more volume capacity under load, and the OEM-style hangers and clamps lock it in clean with no welding. Turbochargers enhance the performance of engines by increasing power and improving fuel efficiency.^[2] The 6.7-liter engine's VGT utilizes 16 fixed vanes and a sliding yoke, providing variable geometry, as well as an electric valve.^[1]

Let's break it down, because the diameter argument gets shouted a lot and explained almost never.

What backpressure does when the truck is loaded

Start with what the factory system does to itself.

The stock exhaust routes through a DPF that traps soot, then burns it off in regen cycles that waste fuel and heat your engine. Every one of those cycles is heat you did not ask for. On a truck that spends its weekends on the dyno or hooked to a sled, heat is already the thing you are fighting.

Unrestricted flow keeps exhaust temps down […], wakes up throttle response, and lets the turbo breathe. That is the whole argument for the bigger pipe, in one line.

How a variable geometry turbo reads the exhaust side

Your turbo is not a passive part sitting in the stream. It is reading pressure and changing shape to suit it.

Variable Geometry Turbochargers (VGT) work by varying the exhaust passage area before the exhaust gas entry into the turbine wheel.^[2] In diesel engines, internal combustion results in expansion of high-temperature, high-pressure gases, which in turn move pistons.^[3] Those gases have to leave afterward, and the exhaust side is the doorway they leave through. A turbo is only ever as quick as what it can push out.

Where the diameter argument runs out

Here's the honest version. Diameter is one variable, not the whole build.

A bigger pipe does not write your tune for you, and it does not touch the recirculation side of the engine. Chasing flow on one side while ignoring the other is like fixing a leaky roof on one half of the house. Want the most restriction gone? That is the one to run. Want the cheaper route through the same years? Keep reading.

What Separates the 4-Inch System From the 5-Inch System?

Material is the first thing that separates them. T-409 stainless stands up to real heat cycles, and OEM-style hangers and clamps bolt to factory mount locations — no welding. This 4" aluminized steel exhaust runs downpipe-back, replacing the OEM DPF and CAT sections with a straight, free-flowing pipe. The 5-inch stainless pipe fits a 2013-2018 Ram. A second 5-inch pipe fits the 2007.5-2012 Ram.

Three things separate these systems: what they are made of, where they start, and what they sound like. Take them in that order.

Aluminized steel and T-409 stainless, and what each is for

Steel is where the price gap lives, and it is the difference a buyer can actually feel.

You get the T-409 stainless exhaust, the hangers and clamps, and a step-by-step guide. Stainless is the material you buy when the truck lives outside and works hard. Aluminized is the material you buy when the truck is a build in progress and the money has somewhere better to be.

Neither one is wrong. They are answers to different questions.

Turbo-back or downpipe-back: where the system starts

Turbo-back or downpipe-back — that is where the two systems part company.

The 5" Full Exhaust System for 2013–2018 Ram 6.7L Cummins is a full turbo-back pipe in T-409 stainless steel that removes the Diesel Particulate Filter (DPF) and Catalytic Converter (CAT) from your 2500 or 3500 — ending the regen cycles, backpressure, and EGT spikes that choke these engines under load.

This is a downpipe-back system in high-quality aluminized steel that replaces the factory DPF and CAT with a straight, free-flowing pipe. Turbo-back starts at the turbo. Downpipe-back picks the system up one joint later. That extra section is the part people argue about at the pits.

Sound, and the one option that changes it

Sound is the part nobody asks about until the truck is running, and then it is the only part anybody talks about.

A muffler option is available at checkout if you want to take the edge off the sound. One box ticked, and the note changes. Leave it unticked and the truck sounds like what it is.

What Power Does the 6.7L Cummins Put Through That Pipe?

The 6.7-liter Cummins Standard-Output Turbo Diesel produces 370 horsepower and 850 lb-ft of torque in the Ram 2500.^[6] The High-Output version produces 420 horsepower and 1,075 lb-ft of torque in the Ram 3500.^[5] Nearly 70% of all Ram 2500 and 3500 Heavy Duty pickup owners choose the Cummins Turbo Diesel as their powertrain of choice.^[4]

That is what the pipe is carrying. Worth knowing before you argue about diameter.

Standard output and high output, and which truck gets which

Two ratings, two trucks. Knowing which one is under your hood tells you what the exhaust side is actually handling.

For RAM 2500 and 3500 equipped with a 68RFE Auto, horsepower and torque have increased to 370 hp and 850 lb-ft.^[7] The high-output engine boasts 420 hp and 1,075 lb-ft of torque.^[7] Neither number changes which pipe fits your truck — the year bracket still decides that — but it does tell you how much air the engine is trying to move.

The latest generation Cummins 6.7L Turbo Diesel is a heavy-duty pickup engine that delivers the power, quietness, cold-weather reliability, and serviceability that truck owners depend on every day.^[8] Built like tanks, and they earn it.

The exhaust brake that came from the factory

There is one more thing hanging off this engine's exhaust side, and it did not come from an aftermarket box.

For the first time in a Dodge Ram Heavy Duty truck, an integrated exhaust brake is available direct from the factory.^[1] Worth knowing before you start pulling sections, because it lives up front where the turbo is and not back where the filter was.

What Should You Expect During Installation?

OEM-style hangers and clamps lock it in the same way the factory exhaust did, so the fit is clean and rattle-free with no welding. The first thing you should do is verify you have all the parts. Trucks with airbag suspension will need a routing adjustment. Depending on your truck bed, you may need to cut your pipe to modify your pipe length for fitment.

The good news? None of this is exotic. It is hand tools, a couple of hours, and a plan.

The parts check before anything comes off the truck

Ten minutes on the floor beats an hour on your back.

You get the turbo-back pipe, hangers and clamps, all install hardware, and a step-by-step guide. Lay it all out before a single clamp comes loose. Count the hangers, count the clamps, find the guide, and put the whole lot where you can reach it from under the truck. That way you are not scrambling at the parts store mid-install.

Airbag suspension and bed length: the two adjustments

Two adjustments come up often enough to plan for, and both are predictable.

Airbag suspension is the first one. The pipe wants some of the same space the bag does, so the fix is routing rather than cutting. Bed length is the second. Measure twice before the cutoff wheel comes out, because a pipe cut short is a pipe you buy again.

What a Cab&Chassis truck needs that a pickup does not

Cab & Chassis owners, this part is yours.

The instruction sets require minor modifications on Cab&Chassis models. So plan for a little fabrication time rather than a clean bolt-on. Not sure which bracket your cab sits in? Call (888) 830-2588 before you order, not after the box is open.

The tune, and why it is part of the job

The pipe is half of it. The other half is software, and skipping it is the single most expensive mistake on this page.

You'll need a compatible delete tune to prevent DPF codes. Pull the hardware without one and the ECM keeps hunting for a filter that is no longer there. Wall of DTCs, dash lit up, truck looking for a regen it can never finish. Order both together and the truck goes back on the ground the same afternoon.

Which Exhaust Should You Buy for Your Truck?

For a 2008 through 2012 Ram, the 5-inch DPF delete runs $849.00 to $1029.00. For 2013 through 2018, the 5-inch full exhaust runs $799.00 to $869.00. The 4-inch system for those same years runs $699.00 to $775.00. For 2019 through 2024, the 4-inch full exhaust runs $699.00 to $824.00.

Three brackets, one real fork. Here is where each one lands.

5" Exhaust DPF Delete | Dodge Ram 6.7L Cummins 2007.5-2012

For a 2008 through 2012 Ram with the Cummins 6.7L, this is the 5-inch system that fits those years. One diameter, one listing, one decision — the easiest call on the page.

It runs OEM-style hangers and clamps, bolts on across all cab and box lengths, and ships free.

5" Full Exhaust System | Ram 6.7L Cummins 2013-2018

For a 2013 through 2018 Ram with the Cummins 6.7L, this is the turbo-back 5-inch choice. Take it if the truck is a competition build and you want the most restriction gone in one purchase. Turbo-back means you replace the whole run in one go instead of coming back for the front section later.

4" Full Exhaust System | Ram 6.7L Cummins 2013-2018

For a 2013 through 2018 Ram with the Cummins 6.7L, this is the aluminized-steel alternative to the 5-inch pipe. It is the same year bracket for less money, and on a build that is still coming together it is the better bang for your buck.

That is the fork. Stainless and turbo-back, or aluminized and downpipe-back, on the same truck.

4" Full Exhaust System | Ram 6.7L Cummins 2019-2024

For a 2019 through 2024 Ram with the Cummins 6.7L, this is the full exhaust that covers the truck. One listing, one diameter, no fork.

Trucks these systems do not cover

This is the paragraph that saves you a return label, so read it once and move on.

It fits 2007.5 through 2012 Ram 2500 and 3500 with the 6.7L Cummins, all cab and box lengths, and does not fit Cab & Chassis trucks, 5.9L Cummins, or 2013+ 6.7L. It fits all cab and box lengths, including HD models, but does not fit Cab & Chassis trucks or 2018-and-earlier 6.7L Cummins engines.

Two brackets, two sets of exclusions, and both of them come down to the same thing. Check the year, check the engine, check whether the frame ends in a bed or a bare rail.

What happens after you order

Cummins engines have been an option in RAM pickups since 1989.^[9] That is a long time for a parts market to mature, and it is why the box that turns up actually fits.

Free shipping is included, with standard delivery in 8-10 business days and express available at 5-8. Plan the install for the weekend after it lands rather than the weekend it lands. Pipes travel a long way, and a truck on stands waiting for a box is a truck you cannot use.