5 Power Stroke Upgrades for Your 6.4- and 6.7-Liter Engines

Ford has been in the diesel pickup game for a long time—all the way back to its anemic IDI offerings in the 1980s. In the later 1990s and early 2000s, Ford’s diesels got a whole lot more capable, and big power boosts were available with the addition of computer tuning, larger injectors, and other performance parts. Building big power and improving fuel mileage is still a concern for many Power Stroke owners, and to get some advice about how to make this happen, we reached out to Power Stroke experts on opposite ends of the country; Strictly Diesel of Phoenix, Arizona, and KT Performance, in Groveland, Florida.

But before we get started, we have to note that any power gains realized will definitely depend on the truck you choose to start with. For instance, the 7.3-liter Power Stroke checks in at 225 to 275 horsepower, depending on the year of the truck. Then came the 6.0-liter engine with 300 horsepower, followed by the very capable 6.4-liter engine from 2008 through 2010, which delivered 350 horsepower. In 2011, the 6.7-liter engine was introduced, and although it initially made 390 horsepower, its power has steadily risen throughout the years. In 2023, Power Stroke engines are available with a mammoth 500 horsepower and 1,200 lb-ft of torque! Ok, but enough with the history lesson.

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Although the Power Stroke is a very capable engine in stock form, we also realize that all enthusiasts want to make more power. For that reason, we thought we would put together a short list to show you a few ways that you can increase your Power Stroke’s output without breaking the bank.

Step One: Intake And Exhaust Systems

A large number of enthusiasts start off with the basics when it comes to modifying their Ford, and that usually begins with an intake and exhaust system, which come in at around $300 to $500 for the intakes, and $400 to $800 for the exhaust. On a stock vehicle, this does make a bit of a horsepower difference (10 to 20 horsepower for the intake, and a little less for the exhaust). “We especially see gains across the board,” notes Gary Maschner at Strictly Diesel. “…and many of them are 50-state legal too.”  One of the more prevalent complaints among those actually looking to modify their trucks is that it doesn’t sound like a diesel should.

In an effort to please everyone, the OEMs have made new trucks extremely quiet and have almost eliminated all turbo and exhaust noise. While it might not add huge amounts of power, an intake will deliver small gains and free up some turbo whistle and a DPF-back exhaust can give the engine just a bit more “bark.” These are also good supporting mods for when you end up making more power down the line. We tested an aFe POWER cold air intake and a DPF-back exhaust in a previous article, and you can check that out here.

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This aFe POWER cold air kit for 2011 through 2016 6.7-liter engines is reported to deliver 19 additional horsepower and 60lb-ft of torque. It is definitely a quick and easy upgrade that delivers.

Step Two: Pedal Boosters

Another item that is simple, easy to install, and makes the truck a lot more fun to drive can be found in the form of a pedal booster. In factory form, diesel trucks come with a drive-by-wire throttle pedal. This electronically actuated pedal does not have the responsiveness found with actual linkage. So, adding a throttle sensitivity controller is a great way to improve throttle response. Pedal boosters will take this “lag” out of the truck and give you a much more linear throttle response. In talking to Chris Searl at KT Performance, we learned they are highly recommended for all of the newer 6.4- and 6.7-liter-equipped trucks. Although they don’t exactly add peak power, they can improve part throttle power, and driving performance is much improved. Another advantage is they’re cheap, as most pedal boosters come in at under $400.

Throttle enhancers (aka pedal boosters) are a good way to improve the all-around performance of both 6.4 and 6.7-liter-powered Fords and can be had for under $400.

Step Three: Power Stroke Tuning

Out of all the products mentioned so far, computer tuning has by far the greatest ability to add power to your diesel truck. There are a number of options for pre-programmed tuning that is 50-state legal from companies like Bully Dog and Edge Products that can add 50 to 100 horsepower to your Power Stroke. In factory form, there’s a bit of a tuning window left over, and aftermarket companies can take advantage of this by adding more timing, or increasing rail pressure for a more effective burn.

One thing that isn’t often mentioned is transmission tuning, which we found out was worth almost a half a second in the quarter mile on a 6.4-liter Ford. And that was achieved with no extra tuning or power adders. Regeneration cycles for your DPF can also lessen (depending on your driving style) and you’ll probably see about a one to two mpg gain. For a price of $500 to $800, if you’re looking for a “bang for the buck” type deal, computer tuning is perhaps the best way to go.

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Monitors like this version from Edge can add more than 100 horsepower to your newer Ford, all while retaining the factory emissions. As far as power gains go, they’re definitely the top dog.

Step Four: Drop-In Power Stroke Turbochargers

Turbo technology has come a long way in recent years, but if you’re looking for the latest and greatest advancement, a turbo upgrade might be in your future. Since many companies offer emissions-compliant upgrades, why not get a better turbo? We sat with KT Performance on this one, and they said there are a variety of turbo options available, and compound turbos are even available for the 6.4 engine, and the 6.7-liter’s triple wheel turbos (’11 to ’14). You late-model Power Stroke guys with 2015 and newer trucks can benefit from upgraded normal turbine/compressor setups.

These drop-in turbos feature upgraded bearings, and larger billet compressor wheels in stock housings to save costs. They also fall mostly in the $1,500 to $2,000 range but can add horsepower, greatly reduce EGT, and spool up quicker. Because of its cost, and because turbo upgrades are most effective with tuning and intake/exhaust upgrades, we saved this one for last, although we’ve definitely seen the benefits in EGT reduction and power.

Although they’re one of the more expensive modifications, drop-in turbos can add power all on their own, and also really take advantage of other power upgrades like tunes and intake systems.

Step Five: Wheels And Tires

When it comes to power, it’s easy to have your brain 100-percent focused on the engine, because that’s where the power is made, right? Well, sort of. That horsepower still has to make it to the rear wheels, so there are transmission and driveline losses as well as your wheels and tires that all sap horsepower from your engine’s flywheel.
Recently we’ve seen two different trends in diesels, one is to go with a huge lift and 22 through 26-inch wheels along with 37-plus-inch tires, while the other is to actually lower the rear (or “level” the truck) and go with the factory 20-inch size wheels or even 18s, along with an on-road tire. While this isn’t probably the perfect setup to tow a 40-foot toy hauler, the weight savings can be surprising. Dropping from the factory 275/60R20 Michelins for instance to 285/50R20 Toyo Proxes ST III truck and SUV tire will drop a couple of inches in tire size, but based upon manufacturers’ weight ratings it’ll also drop a whopping 18 pounds per tire or a whopping 72 pounds in total. And before you say the smaller tire will increase engine RPM and negate the gain from the weight loss, there’s a point where less RPM can actually hurt mileage because the engine is under so much load. With a .67 overdrive in Sixth gear, it shouldn’t matter too much. Rear gears range anywhere from 3.31s to 4.30s, so that is going to make a much bigger difference. This means better performance, handling, and increased mileage, all for about $800.

If you do a lot of on-road driving, going to a lightweight tire like the Toyo Proxes ST III truck and SUV tire can help conserve fuel and also improve performance.

If you’re looking for even more weight savings you can attack the wheels too. For instance, Weld Racing makes a lightweight off-road wheel called the Granada Eight, which shaves off about another five pounds per corner. Although the wheels and tires together break our $2,000 limit, you can always sell your stockers to recoup some of your expenditure. And Although the Toyos are XL rated, the tires can carry a 2,756-pound load, so towing is still on the table, although probably not as heavy as with the 3,750-pound-rated Michelins.

Wrapping it Up

The lesson here is that diesel performance is here to stay, and there are plenty of modifications you can perform, on a budget. There’s no reason not to personalize your truck with extra looks, power, and performance. And even if you have an older truck (all the way back to the 7.3-liter Power Stroke) these simple modifications can still work for you. As they say, stock is boring, so get out there and start upgrading.

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About the author

Jason Sands

Jason Sands has owned everything from an 8-second Nova to rat rods. His claim to fame is setting the Guinness World Record for the fastest speed towing a trailer at 141.998 mph in a diesel-powered GMC Duramax. He's also known to write on occasion.
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