Clean power has to be the way forward for diesel trucks as the government keeps cracking down on emissions defeat devices.
The commonly held belief is you can’t make more power with newer diesel trucks unless you strip the emissions equipment. Sure, that’s the quickest and simplest way to do it, but it’s also illegal in case you haven’t heard. That’s why I’m writing about this 2021 Ford Super Duty with just a 64-millimeter turbo from Ryan’s Diesel Service and a PPEI tune. The 6.7-liter Power Stroke now lays down 632 horsepower and 1,230 pound-feet of torque on the dyno while retaining the EGR, DPF, and everything else.
Those are huge gains in both categories as the truck is rated at 475 hp and 1,050 lb-ft from the factory. PPEI founder Kory Willis said on Instagram that the truck made 448 hp at the tire in stock form, which is surprisingly close to the quoted crank power numbers. And now this truck is significantly more potent than a new Super Duty with the high-output 6.7-liter, which makes a nice, round 500 hp and 1,200 lb-ft of torque.
PPEI didn’t hit 632 hp on its first try, of course. It took a series of tweaks—mainly to ignition timing and boost parameters—to safely hit that peak. And Willis says it could make even more power if they weren’t also trying to stay close to the stock emissions output. The point of all this is to develop a package that increases power significantly while still passing smog tests in California and other CARB states.
To be clear, this tune and turbo combo isn’t CARB-ready just yet. It still requires a CARB Executive Order number, which takes a lot of testing on the manufacturers’ end. PPEI is confident it will pass these tests as it apparently keeps emissions within 10% of the OEM’s standards. And better yet, because the NOx numbers have barely changed, it supposedly doesn’t slurp more diesel exhaust fluid than stock.
Tuning modern diesel engines with the emissions systems in place is a tough game. It requires a lot of hands-on testing as past know-how with emissions-absent trucks just won’t cut it. Adjustments must be made carefully so they don’t spike tailpipe emissions or force excessive diesel particulate filter regens, and in general, there’s way more working against tuners than in the past. To this point, few have done it with success, though the EPA has made it clear that compliance is the only way forward if companies want to avoid millions or even billions of dollars in fines.
Here’s hoping we see more clean tuning like this. Diesel performance is still a huge area of interest, but it needs to be done legally. If PPEI and Ryan’s Diesel Service can pass this setup, it opens the door for more.
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