Flowmaster’s HEMI Exhaust: Going Magnum!

In this modern age of muscle cars, look no further than the new and improved HEMI platform from Chrysler/Dodge. The modern generation HEMI was introduced in four different muscle car platforms; the Charger, Magnum, 300, and Challenger. While the Challenger stands alone holding the “heritage mark,” the Charger, Magnum and 300C all share a very similar platform of muscle meets modern technology.

With such a popular fan base, these HEMI powered vehicles appealed almost instantly to the aftermarket. And what’s the first thing you typically think of in aftermarket performance? Exhaust. So what’s our solution? We called up one of the most famous names in the industry: Flowmaster.


One of our project cars at PowerTV is a 2007 Dodge Magnum R/T 5.7 Liter HEMI, fully equipped with a Vortech Supercharger, Diablosport Tune, 20 inch rims, and a few cosmetic upgrades. The stock exhaust has been a major hindrance in both performance and muscle car sound, failing to match the car’s aggressive stance.

Lucky for us, Flowmaster just introduced a complete line of 409S stainless steel exhaust systems to complement their already vast lineup of offerings. These systems will prove to be more durable, better sounding, and better looking underneath the vehicle. Included in this new lineup is a 409S stainless exhaust system for the HEMI platform. That fit the bill just perfectly for our Magnum. Finally! A little something to help this HEMI breathe!

Flowmaster’s 409S Force II Cat-Back

This is Flowmaster’s new Force II® Cat-Back kit for 2005-09 Dodge Magnum RT, but similar kits are available for the Charger RT and Chrysler 300C 5.7L with HEMI engines (including AWD). The particular kit that we’ll be installing is part number 817405. This 409S stainless steel system uses dual 2.50-inch mandrel bent tubing which leads to the patented Flowmaster Scavenger X-pipe and twin Super 44 Series mufflers. The kit also includes matching stainless tailpipes with resonators just ahead of the Flowmaster-embossed 4.00-inch diameter tips. The resonators are what sets the Force II kit apart from the American Thunder kit (which does not include them), giving it a louder, throatier sound.

The Flowmaster Force II kit delivers a moderate exterior tone and moderate to mild interior tone and features all of the accessories necessary for an easy at home installation. Best of all, this stainless steel kit is covered by Flowmaster’s 10-year limited warranty.

We of course put the system to the test by distinguishing different exhaust tones during different times of vehicle use between stock and the Flowmaster kit.

Before the Install: Sound Impressions

We took the Magnum out for its stock test first. We began with ignition and idle sound tests. The stock exhaust sounds…well, stock. It has a bit of a rumble to it simply because it’s a V8, but it’s nothing to boast about.

Next, we revved the engine a bit, then did some hard launches to hear the stock exhaust at full throttle. Again, it sounded stock. Loud enough to get some angry looks from the neighbors, but probably not loud enough to be heard from a block away.

Finally, we drove the car as fast as legally possible past our listening point so we could hear what the stock exhaust sounded like as it drove past. You could tell that this HEMI needed that Flowmaster system – badly!

After the stock tests, we brought the Magnum up on the lift to do the quick and easy install of the Flowmaster Force II exhaust.

The stock exhaust system was quickly removed, and starting with the Flowmaster scavenger X-pipe, we began installing the Flowmaster exhaust from the mid-pipes back as this is a cat-back exhaust system.

Following the X-pipe, we clamped on the two Flowmaster Super 44 series mufflers for that “Flowmaster sound.”

The clamps used in the kit are premium, zinc coated ring style clamps that will hold up to the weather and pretty much any extreme conditions you want to throw at them.


Scavenger X-pipe for increased flow.

Next we installed the tailpipes, which include the tuned tailpipe resonators to provide minimal interior resonance, and along with the Super 44 mufflers supply a healthy, refined exterior sound with mild to moderate interior sound level.

The system utilizes all factory hanger mounts/locations for a true bolt-on installation. Last but certainly not least, we mated the 4-inch polished exhaust tips up with the resonators to give the system a perfect fit and finish. We completed the entire installation in just about half an hour.

It was time to have some fun…or hear some fun…or listen to some fun. Whichever way you want to say it! At any rate, we were ready to go. Once we fired up the HEMI engine in our Magnum, we could immediately hear the difference in the power sound the exhaust now had. Our HEMI not only sounded good, but could breathe much better with limited restriction.

Flowmaster: Sound & Performance Impressions

It was time to go test it. We again started with ignition and idle sounds, but this time, the Flowmaster exhaust provided that deep throaty signature Flowmaster sound.

Revving the car sounded even better, producing a nice healthy exhaust tone – again, very powerful. This time, when launching from a dead stop, you could hear the exhaust from a block away, giving it head turning appeal. Finally, a muscle car sound to match the muscle car look and HEMI name.

Our drive-by sound tests proved to be just as good. The Magnum roared by at full throttle with a healthy, refined exterior sound worthy of the Flowmaster brand.

Flowmaster makes it easy to upgrade your HEMI with a true performance bolt-on exhaust system. It’s a great performance mod for anyone looking to go all out, or for the person who wants the bare minimum in performance bolt-ons.

The 409S Flowmaster exhaust systems set the industry standard for both exhaust tone and performance gains and it continues to live on as one of the most known names in the industry. If you’ve got a HEMI, we highly recommend a Flowmaster system for your car.

Hot Rods and Muscle Cars in your inbox.

Build your own custom newsletter with the content you love from Street Muscle, directly to your inbox, absolutely FREE!

Free WordPress Themes
Street Muscle NEWSLETTER - SIGN UP FREE!

We will safeguard your e-mail and only send content you request.

Street Muscle - The Ultimate Muscle Car Magazine

We'll send you the most interesting Street Muscle articles, news, car features, and videos every week.

Street Muscle - The Ultimate Muscle Car Magazine

Street Muscle NEWSLETTER - SIGN UP FREE!

We will safeguard your e-mail and only send content you request.

Street Muscle - The Ultimate Muscle Car Magazine

Thank you for your subscription.

Subscribe to more FREE Online Magazines!

We think you might like...



Classic Ford Performance

Street Rods

Classic Chevy Magazine

Street Muscle - The Ultimate Muscle Car Magazine

Thank you for your subscription.

Subscribe to more FREE Online Magazines!

We think you might like...

  • Classic Ford Performance
  • Street Rods
  • Classic Chevy Magazine

Street Muscle - The Ultimate Muscle Car Magazine

Thank you for your subscription.

Thank you for your subscription.

Street Muscle - The Ultimate Muscle Car Magazine

Thank you for your subscription.

Thank you for your subscription.

Loading