Best 6.7 Cummins Upgrades - 4 Mods for 500+rwhp
The 6.7 Cummins has long been lacking in horsepower compared to its competitors - the 6.7 PowerStroke and 6.6 Duramax. However, the Ram 6.7L diesel is still an excellent engine that's incredibly capable with some basic performance upgrades. A tuner, intake, intercooler, and exhaust can push the engine into the 500whp ballpark. In this guide, we discuss these four mods we recommend to take the 6.7 Cummins to the next level.
Engine Changes Over the Years
We want to save most of the space in this article for the upgrades and exciting topics, so we'll avoid being too technical or lengthy here. However, it's important to briefly address the fact that the ISB 6.7 Cummins has been through some changes since its introduction in 2007.
Notably, the 6.7 Cummins initially delivered 350 horsepower and 650 lb-ft of torque. It's a far cry from the current performance of 420 horsepower and 1,075 lb-ft. There have also been other major changes over the years like the introduction of SCR and DEF in 2013, new transmissions, and the moves from the Bosch CP3 to the CP4 injection pump and back to the CP3.
Again, this is a short list and description of just a few changes. The main point is that not all 6.7 Cummins engines will see the exact same power gains from these mods. However, some things do remain the same: a tune, intake, intercooler, and exhaust are some of the best basic upgrades to push the diesel engine to the next level. That holds true regardless of which year or model you have.
*Note - all 6.7 Cummins engines will end up in roughly the same 500-525whp ballpark with these upgrades. However, power gains vary due to different starting points. For example, gains will appear more impressive on a 2008 Cummins with a 350hp and 650 lb-ft starting point compared to a 2018 HO with 385hp and 930 lb-ft.
6.7 Cummins Power Limits
Now, it's important to note the 6.7 Cummins can break past the 500whp mark with bolt-on mods and tuning. However, the diesel starts to run into some expensive roadblocks including:
- 68RFE Transmission
- Cylinder Head
- Fuel System
All of these components start reaching their upper limits around the 500-550whp ballpark. Unfortunately, it means spending $10,000+ if you really want to make bigger power numbers. The fuel system is the most expensive part since it requires upgrades to the injectors, CP3 pump, and lift pump. Throw in head studs, transmission mods, a turbo upgrade, and other supporting mods and it gets incredibly expensive.
Ultimately, the basic bolt-on upgrades we discuss in this guide are enough to push the 6.7 Cummins right to its ~500-525whp limit. It's often not worth going beyond that power due to the costly, extensive mods that are required.
The 4 Best 6.7 Cummins Upgrades
These 4 upgrades alone can push the 6.7 Cummins to 500+whp. Let's jump in and discuss the mods in-depth including benefits, power gains, cost, and some of the best products available.
1) MADS Smarty Tuner
The MADS Smarty tuners are some of the most popular and respected tuners on the market for the 6.7 Cummins diesel. There are three different options: the Smarty (07-09), Smarty Junior (07-12), and Smarty Touch S2G (07-18). The Smarty and Smarty Junior are good options if you're looking for a simpler, more basic tuner. However, our main focus and true recommendation is the Smarty Touch S2G.
It's a combined tuner and digital touch display with a customizable background and endless configuration options. It includes 10 preloaded, dyno-proven tunes that can deliver up to 210 horsepower gains. The Smarty Touch S2G also includes an SD card to store additional tunes and custom tuning.
The only flaw is that it's priced on the higher-end with a starting price of $865. There's an optional EGT probe for $158, and the MADS ComMod (required for 2013+ trucks) for $209. Ultimately, it's far from the cheapest 6.7 Cummins tuner. However, the MADS Smarty Touch S2G is one of the most complete, effective, and proven tuners around making the price more than worth it.
EFI Live Tuning
When it comes to all-out Cummins builds, EFI Live is by far the best tuning solution. We highly recommend EFI Live for 550+whp builds on upgraded fuel systems and an upgraded turbo. It's also one of few tuning options for 2019+ 6.7 Cummins diesels. However, EFI is often overkill for basic bolt-on trucks as it can be more expensive and complex for a top-tier setup.
For one, the device doesn't come with any preloaded tunes - it's all about custom tuning. The starting price with custom tuning is often in the $900-1,400 ballpark. EFI Live's device itself is also a bit lackluster compared to the MADS Smarty Touch; if you want a truly top-tier setup we recommend using the Edge Insight CTS3 for monitoring.
Ultimately, EFI Live can get very expensive and is a bit more complex. It does offer some great benefits like being the only device capable of transmission tuning. It's the absolute best tuning solution for high power 6.7 Cummins. However, it's a little overkill for basic builds which is why we still recommend the MADS Smarty Touch S2G for most.
2) Boosted Performance 4" Intake
Following a tune, an upgraded intake is often the next best modification for the 6.7 Cummins. Tunes add a significant amount of power and boost which can quickly overwhelm the factory intake. A larger, more efficient intake helps support the more demanding airflow, reduce stress on the turbo, and lower EGT's.
A 6.7 Cummins intake offers gains of about 5-10whp and 20-30wtq. Solid power gains for a relatively cheap and simple mod. Intake upgrades also improve throttle response, turbo spool, and can deliver a 1-2mpg improvement. The fuel savings at the pump really add up, and can offset the cost of the intake in less than a year or two.
Our Boosted Performance intake is a full 4" open intake system with a high-quality S&B filter. For $299, it's the best balance of price, performance, and quality around.
Price: $299 | Buy Here
3) Banks Techni-Cooler Intercooler
The stock 6.7 Cummins intercooler does its job fairly well on completely stock trucks. However, it's small and becomes inefficient - especially in 2013-2018 models - once you begin increasing boost and power. The extra heat quickly overwhelms the factory IC, which ultimately leads to heat soak and high intake air temperatures (IAT).
Not only is hot air less dense, but the PCM will also start pulling timing and performance in general to help protect the engine. Furthermore, heat and high EGT's are detrimental to reliability and longevity. Enter a larger and more efficient intercooler upgrade.
For 2013-2018 models, the Banks Techni-Cooler intercooler upgrade offers a 79% increase in surface area and 48% increase in airflow. It also shows a 55% reduction in pressure loss. Banks quotes gains of 27 horsepower and 51 lb-ft of torque. We believe those numbers are a bit aggressive for maximum gains. However, an intercooler does deliver consistent performance and can certainly prevent your truck from losing 20+ horsepower.
One downside of intercooler upgrades is the price - they aren't cheap. However, once you begin tuning and modding the 6.7 Cummins then an intercooler is an excellent upgrade. They deliver a great balance of performance, consistency, and reliability.
Price: $1,539 (07-09), $1,829 (13-18) | Buy Here
4) Exhaust Upgrades
Last but certainly not least, exhaust upgrades are one of the best 6.7 Cummins diesel upgrades. With more power, boost, and airflow into the engine it's time to consider airflow out of the engine. Exhaust backpressure increases with additional power and boost, so it's important to reduce pressure with the necessary exhaust upgrades.
A 5" exhaust system will offer the best flow and biggest reductions in backpressure and EGT's. However, moving to a 5" system will also require an aftermarket downpipe. A 4" exhaust is also a great upgrade that's a little simpler and cheaper since it won't require any downpipe mods.
Regardless, an exhaust can offer great benefits for the 6.7 Cummins including gains of 5-15whp and 10-30wtq, faster turbo spool, lower EGT's, and improved turbo reliability.
The 6.7 Cummins has been a little lackluster in the horsepower department compared to its PowerStroke and Duramax competitors. However, the 6.7L diesel is still a great engine that has tons of untapped potential. A tune, intake, intercooler, and exhaust can easily push the Cummins to 500+whp and 1,000+ lb-ft.
A tune is the best starting point for modifications and can offer power gains of 150-200+ horsepower. MADS Smarty Touch S2G and EFI Live are both top-tier tuning options with tons of features, benefits, and more. Once you start increasing boost and power, it's time to think about cooling and airflow. As such, intakes, exhaust, and an intercooler are all great additions to a tuned 6.7 Cummins.
If you need any help or have questions please feel free to contact us. We're always happy to provide any recommendations or advice for your Ram 6.7 Cummins!