We recently detailed the new Flowmaster FlowFX cat-back exhaust system for the 2019 Chevrolet Silverado 1500 and 2019 GMC Sierra 1500 Crew Cab and Double Cab with the 5.3-liter engine. Now it’s time to take a look at the company’s American Thunder exhaust kit for the 2019 Silverado/Sierra 1500 Crew Cab and Double Cab with the 6.2-liter engine.
Flowmaster says its American Thunder exhaust kit for the latest generation of General Motors 1500 trucks is “perfect for the person looking for an aggressive sound level outside the truck, with a moderate interior tone.” The kit comes with a 3.5-inch stainless steel inlet tube that flows into a single muffler that then frays into dual 2.5-inch stainless steel tailpipes. Completing the kit are two sets of dual 4.0-inch black ceramic coated stainless steel exhaust tips, which exit in place of the factory bolt-on trim bezels and give the truck a tougher, more performance-oriented appearance.
The company also says this kit was designed for easy installation and comes with all the necessary parts, instructions and hardware for a straightforward DIY install. The kit will not fit the single cab work truck trims or any trucks with the factory single exhaust system. Again, it is designed for the 6.2-liter trucks with the Crew Cab or Double Cab body and 5.5-foot bed only.
You can listen to Flowmaster’s 2019 Chevrolet Silverado and 2019 GMC Sierra exhaust for yourself in the video above. The video includes sound clips taken from both inside the cabin and out of it, along with pre- and post-install dyno videos showing the potential power gains the exhaust kit can provide.
Comments
Just like their other exhaust. The baseline dyno numbers don’t add up. 325 peak rwhp on the 6.2? That’s a 30% parasitic drivetrain loss. Hennessey baseline dyno showed a more reasonable 15% loss.
Their numbers WITH the new exhaust look more like what the stock numbers should be.
Like the last GMA article about the FM exhaust, I’m claiming foul on FM for manipulated dyno sheets.
A 10hp and 10lb-ft PEAK gain is more likely. You’ll feel the exhaust sound in your ‘butt-dyno’ more than you will the actual performance increase.
As always, i recommend a custom tune (data log or dyno) after installing performance parts to reap the most benefit from them
Yeah it looks like they’re manipulating the dyno setup between pulls to get these results. I’ve seen similar bizarre dyno results from some tuners (5star and their ridiculous Gen V 5.3 dyno results for example). Some dynos are very easy to manipulate simply by messing with the calibrations.