One of the world’s most respected aftermarket automotive tuners, Hennessey Performance, has given up on tuning the 2021 Chevy Tahoe after only three days. Not holding any punches and clearly showing frustration the company states: “If you want to modify your new SUV you’ll need to buy something else.”
Recently, the first hint that the company was having issues showed up on the personal facebook profile of the company’s founder, John Hennessey.
John Hennessey: Good news / bad news: We bought a 2021 Chevy Tahoe a few weeks ago and its a wonderful (expensive at $82k) vehicle that drives well, has a beautiful interior and its quick. The bad news is that the ECU is locked which means that the engine cannot be modified. Further, you cant even install taller tires on it as there is no way to recalibrate the speedometer. So if you are in the market for a great factory stock vehicle, I highly recommend the new Tahoe. However, if you’re like me and would like to be able to personalize and modify your new SUV then you would be better off buying something else.
Then, a few days later the company posted the following video to their YouTube Channel after dyno tuning the new Tahoe.
“Chevrolet’s 2021 Tahoe puts down 369 HP and 397 lb-ft of torque at the rear wheels. Sorry folks thats as much as its going to make as the new 2021 GM SUV’s (Tahoe, Suburban, Yukon/Denali and Escalade) have locked ECU’s and thus cannot be modified beyond a cold air intake and catback exhaust system. We hope that GM will consider working with SEMA and the aftermarket industry to come up with a tuning solution for these vehicles. But for now and the foreseeable future, stock power is about all you’re going to get out of their new vehicles. If you want to modify your new SUV you’ll need to buy something else.”
That Hennessey Performance can’t crack the new Tahoe is a big deal. The company has modified everything from the Ford Raptor to Lamborghini Urus. A high-performance Tahoe/Suburban would have been a great addition to the Hennessey lineup.
However, General Motors has other ideas. The company’s new global electronics platform is to blame. It’s locked down- encrypted. Unable to be modified and ruling out big modifications.
Easy bolt on items like intakes and exhaust systems will still work. They typically don’t change the engine performance enough to require cracking into the engine management system. Superchargers, cams, and other internal parts however.. that’s a different story.
High performance additions that change the air-fuel mixture or any basic engine parameters are a no go. With no way to edit the engine management software, performance engineers can’t tune the 2021 Tahoe to run correctly after the upgrades. As John Hennessey said himself, this level of lockdown even eliminates the ability to adjust tire sizing.
Silverado owners may be thinking “So what?” Hennessey has a “Goliath” Silverado with over 700-horsepower. If they can tune the new Silverado, this shouldn’t be a big deal, right?
Wrong. The 2022 Silverado will jump to the same “Global-B” electronics system the 2021 Tahoe uses. So, starting in 2022, this is a full-size truck problem as well.
As we’ve found with our install of Chevrolet Performance parts, the company is really angling to be the provider of a large chunk of the performance upgrades installed the vehicles they sell. Which, could be ok if the company offered more significant upgrades. No, doubt, we love our Brembo Brakes and 2 inch lift.. but more horsepower should always be on the menu.
There’s still hope this issue could be fixed. If GM works with SEMA and Industry Players, it’s possible a way to modify the 2021 Tahoe and 2022 Silverado could be found.
Until then.. don’t get your hopes up…or expect to see any supercharged Tahoes, Yukons, or Escalades. Then starting in 2022, the Silverado and Sierra are in the same boat.