As much as us hot rodders dig the sound of a lumpy-cam V-8 rifling though a set of open headers, after time it can become a bit much. Especially when the car belching out the eardrum-busting note is one you plan on driving on a regular basis, or for a long distance. The decibel battle between your 12-inch subs and your 3-inch header collectors will end up sounding like your favorite two metal bands rocking out at the same time…backwards—not good!
The Flowmaster American Thunder...
The Flowmaster American Thunder System (Part # 17149) 1970-73 Camaro/Firebird kit comes with everything you’ll need for easy installation: hangers, clamps, hanger keepers, screws, and washers. The system comes pre-bent in key locations and is designed for cut-to-fit installation. As a nice addition; the stainless steel mufflers come with a 10-year warranty.
With that being said, it’s also important to let it be known your ride means business. You certainly don’t want your stroked mouse motor to sound like a wheezy rodent. Authority is the name of the game here. Besides, if your car looks aggressive, it needs to sound aggressive. It’s just the way it is.
We called the folks at Flowmaster and told them what we were looking to achieve in the muffler department for our ’71 Camaro Project car. The car will be driven hard, often, and on long distances, so we wanted to keep the exhaust resonance in the interior to a minimum, but we like the idea of announcing our arrival with an aggressive exterior note.
Muffler Man’s chief installer,...
Muffler Man’s chief installer, Josh Gledhill, starts by bolting up the new hanger brackets and rubber mounts in the rear. There are two holes that are punched into frame on either side. He used the supplied self-tapping screws to secure the tailpipe support hangers.
Another important issue is performance. Our ’71 project car sports a pretty healthy small-block, but as conscious as we are about the sound; parasitic horsepower loss is also of concern. We didn’t spend our precious dyno-time fine-tuning the engine just to give away valuable ponies through the tailpipe.
Flowmaster’s American Thunder System #17149 for 1970-73 and Delta Flow 50 muffler was just the ticket for our second-gen project car. The Delta Flow 50 does a great job of eliminating interior resonance while still obtaining that Flowmaster sound outside the car. And the mig-welded 16-gauge aluminized steel promises durability even with everything we’ll be throwing through it. Flowmaster is so confident, they include a a 10-year warranty for their stainless steel mufflers.
Using muffler stands, Josh...
Using muffler stands, Josh mocks the tubing’s route over the rear axle in order to install the stud plates in the rear seat pan. A little tip: raise the car a little, it will make more room over the axle and make snaking the pipe over it easier.
There are many benefits to using the American Thunder system including: reduced backpressure for improved acceleration, cooler underhood temperatures, and better fuel economy (we could all use that). The kit comes with all the necessary clamps, hangers and mounting hardware for ease of installation. Your muffler shop professional will love you for this alone, not to mention the detailed instructions that make for a quick installation.
We hauled the box of muffler pieces to Josh Gledhall over at Muffler Man in Placentia, CA for the install. He’s an expert in the field and was able to take care of business in just a few hours. This guy’s been bending and cutting pipe for quite a few years and even he commented on how simple the installation was. He was especially impressed with how tidy the mufflers tucked under the floors. And that’s a good thing since this car will be sitting on the low. We prefer to keep our muffler scrapage to a minimum.
Follow along as The Muffler Man takes us through the install from beginning to end.
Once into position he then...
Once into position he then marks the drilling points for the rear seat pan stud plates. The arrow shows where the drilling will take place.
The handy instructions call...
The handy instructions call for a 3/8-inch hole to be drilled through the rear seat pan. The holes are intentionally drilled a little oversized to allow for some height adjustment. Another tip: be sure to remove the rear seat before drilling.
With the stud plates bolted...
With the stud plates bolted in, Josh was ready to hang the tailpipe with the supplied mounts and rubber hangers.