What a 6.7 Cummins turbo upgrade does and why owners choose it
A turbo upgrade on a 6.7 Cummins diesel engine increases boost pressure and airflow to the engine, raising horsepower and torque output. Stock 6.7 Cummins engines produce around 370 horsepower and 850 pound-feet of torque. An upgraded turbocharger can push those numbers to 450 horsepower and 950 pound-feet or higher, depending on the turbo model and supporting modifications.
Owners pursue turbo upgrades for three main reasons: towing capacity (more torque moves heavier loads), acceleration (the truck responds faster under throttle), and the ability to support other engine modifications like fuel system upgrades or tuning software. A larger or higher-flowing turbo is often the bottleneck that limits what else you can do to the engine.
The trade-off is cost and complexity. A quality turbo upgrade runs $1,500 to $3,500 for the turbo itself, plus installation labor that typically ranges from $800 to $1,500 depending on your shop. You will also need to decide whether to upgrade supporting parts like the intake, exhaust, or fuel injectors at the same time.
Key Takeaways
- A turbo upgrade increases boost pressure to raise horsepower and torque, with gains of 80 to 100 horsepower and 100 to 150 pound-feet of torque being typical.
- Common upgraded turbos for the 6.7 Cummins include the Garrett PowerMax, BorgWarner EFR, and Holset HE351VE, each with different boost curves and spool characteristics.
- Installation requires removing the factory turbo, replacing gaskets and seals, and reinstalling the new unit — a job that takes 4 to 8 hours at a diesel shop.
- A turbo upgrade alone does not reach its full potential without matching changes to fuel delivery, exhaust flow, and engine tuning.
- Warranty coverage on your truck engine will likely be voided once you install an aftermarket turbo.
Common turbo options for the 6.7 Cummins and what each delivers
The Garrett PowerMax is one of the most popular choices for 6.7 Cummins owners. It spools quickly (meaning it builds boost fast at lower engine speeds) and delivers smooth power across the RPM range. The PowerMax typically adds 80 to 100 horsepower and 120 to 150 pound-feet of torque. It works well for owners who want better everyday drivability without extreme modifications.
The BorgWarner EFR line offers several sizes, with the EFR 7135 and EFR 8374 being common for the 6.7. These turbos spool slightly slower than the PowerMax but produce higher peak boost and are better suited to trucks running aggressive tuning or heavy towing. Expect 100 to 120 horsepower gains and 150 to 180 pound-feet of torque increase.
The Holset HE351VE is a variable geometry turbo that adjusts its internal vanes to optimize boost at different engine speeds. It offers quick spool and strong mid-range torque, making it popular for towing. Gains are similar to the PowerMax — roughly 80 to 100 horsepower and 120 to 150 pound-feet of torque.
Each turbo has different compressor and turbine wheel sizes, which affect how much air it can move and how quickly it responds. Choosing between them depends on your intended use: daily driving favors quick spool and smooth power, while heavy towing or racing favors peak flow and higher boost limits.
What you need to do before installing a new turbo
Before you schedule installation, inspect your engine's current condition. A turbo upgrade puts more stress on the engine, so worn fuel injectors, a failing fuel pump, or carbon buildup in the combustion chamber will become problems faster. Many shops recommend a compression test and fuel system inspection before proceeding.
Decide whether you will upgrade supporting systems at the same time. The factory intake manifold and exhaust can restrict airflow, limiting what your new turbo can do. The factory fuel injectors may not deliver enough fuel to match the increased air. If you plan to run tuning software (which raises fuel pressure and timing), you should upgrade the fuel system first. Doing everything at once costs more upfront but avoids multiple shop visits.
Check your truck's warranty status. Cummins and Dodge will void powertrain warranty coverage once an aftermarket turbo is installed. If your truck is still under factory warranty, you need to decide whether the upgrade is worth losing that protection. Some owners wait until warranty expires; others accept the trade-off for the performance gain.
Get a quote from a diesel shop that has experience with 6.7 Cummins turbos. Prices vary based on whether they are installing just the turbo or a full package (turbo, intake, exhaust, tuning), and labor rates differ by region. A detailed quote should list the turbo model, any gaskets or seals being replaced, and the estimated installation time.
The installation process and what happens at the shop
Turbo installation on a 6.7 Cummins is a full-day job. The technician will lift the truck, remove the belly pan and heat shield, disconnect the oil and coolant lines to the turbo, unbolt the turbo from the exhaust manifold and intake, and remove it from the engine bay. This step alone takes 1 to 2 hours because the turbo is tucked tight against the engine.
Once the old turbo is out, the shop will clean the mounting surfaces, replace the exhaust manifold gasket and turbo inlet gasket (both are one-time seals that cannot be reused), and install the new turbo. They will reconnect the oil and coolant lines, reinstall the heat shield and belly pan, and run the engine to check for leaks. Total time is typically 4 to 8 hours depending on the shop's familiarity with the job and whether any complications arise.
Complications can include stuck bolts (common on older trucks), oil or coolant line corrosion that requires replacement, or damage to the exhaust manifold that needs repair or replacement. A good shop will call you before proceeding with extra work and give you a revised quote. Budget an extra $200 to $500 for unexpected repairs.
After installation, the shop should perform a boost test to confirm the turbo is building the expected pressure and that there are no vacuum leaks. Some shops will also log engine data during a test drive to verify fuel pressure, exhaust temperature, and other parameters are in the safe range.
How to get the most performance from your new turbo
A turbo upgrade alone will not reach its full potential without matching changes elsewhere. The factory fuel system is calibrated for the stock turbo's airflow. When you increase boost, you need more fuel to match that air, or the engine will run lean (too much air, not enough fuel) and risk damage.
Most owners pair a turbo upgrade with tuning software (also called a tune or ECU flash). This reprograms the engine computer to increase fuel pressure, adjust timing, and raise boost limits. A quality tune costs $400 to $800 and is usually done at the same shop that installed the turbo. The tune should be matched to your specific turbo and any other modifications you have made.
An upgraded intake system (intake manifold, intercooler piping, or both) can improve airflow to the turbo and reduce intake temperatures. This is not always necessary but becomes more valuable if you are running aggressive tuning or towing in hot weather. Expect $300 to $800 for intake upgrades.
An upgraded exhaust system (downpipe, exhaust manifold, or both) reduces backpressure and allows the turbo to spool faster. Factory exhaust components are restrictive by design for emissions compliance. Upgrading them can add 20 to 40 horsepower on top of the turbo gains. Cost ranges from $400 to $1,200 depending on what you replace.
If you are running tuning software and pushing higher boost, monitor your exhaust gas temperature (EGT) regularly. Diesel engines can overheat internally if pushed too hard, especially while towing. Many owners install an EGT gauge to keep an eye on this. Staying below 1,200 degrees Fahrenheit is a safe target for daily driving.
Maintenance and long-term durability after a turbo upgrade
A quality aftermarket turbo will last as long as the factory unit if you maintain the engine properly. The most common failure point is oil starvation — if the turbo does not receive clean oil at the right pressure, the bearings wear out quickly. Change your oil and filter on schedule (every 5,000 to 7,500 miles for diesel engines) and use the grade specified in your owner's manual.
Diesel fuel quality matters more with a turbo upgrade because fuel injectors are working harder. Use fuel from reputable stations and consider adding a fuel filter or water separator if you operate in dusty conditions. Contaminated fuel can clog injectors and cause rough running or loss of power.
Check your intercooler and intake piping for boost leaks periodically. A small crack or loose clamp can reduce boost pressure and trigger a check engine light. These are cheap and straightforward to fix if caught early but can damage the turbo if left alone.
If you are towing regularly, monitor coolant temperature and exhaust gas temperature. A turbo upgrade increases heat output, so your cooling system works harder. If your truck runs hot under load, you may need to upgrade the radiator or add an auxiliary cooler.
Frequently Asked Questions
Will a turbo upgrade void my truck's warranty?
Yes. Cummins and Dodge consider an aftermarket turbo a major modification and will void powertrain warranty coverage. Some dealers may still cover unrelated repairs (like suspension or electrical), but engine and transmission work will be denied. Check your warranty documents or call your dealer if you are unsure.
Can I install a turbo upgrade myself?
It is possible if you have diesel engine experience and proper tools, but most owners take it to a shop. The job requires lifting the truck safely, disconnecting oil and coolant lines without spilling fluid, and torquing bolts to exact specifications. A mistake can cause oil leaks, coolant leaks, or boost leaks that damage the engine. Shop labor is usually worth the cost.
How much horsepower will I actually gain?
A turbo upgrade alone typically adds 80 to 100 horsepower. If you also upgrade the fuel system and add tuning software, you can reach 120 to 150 horsepower gains. The exact number depends on the turbo model, your truck's condition, and what other modifications you have done. A shop can log your truck before and after to show you the real numbers.
Do I need to upgrade fuel injectors at the same time?
Not always. Stock 6.7 Cummins fuel injectors can handle a moderate turbo upgrade with conservative tuning. If you are running aggressive tuning or planning to push high boost, upgraded injectors (usually $600 to $1,000 installed) will give you more headroom and better reliability. Ask your tuner whether your injectors are adequate for your planned setup.
What is the difference between a turbo upgrade and a turbo replacement?
A turbo replacement means installing a new factory-equivalent turbo when yours fails. A turbo upgrade means installing a larger or higher-flowing aftermarket turbo to increase performance. An upgrade is a choice; a replacement is a repair. Upgrades cost more but deliver more power.