The Sound Of Music

Selecting the Appropriate "Sound" for your Pickup

What really makes a truck? Above and beyond its heritage--that being the year, make, and model--each truck has individual traits, most often characterized by color and wheel choice. But there's more to it than that, and it starts under the hood.

Engines give trucks a majority of their character. Without having to open the hood, you can usually tell what's going on underneath--whether it's an inline-six, V-6, Flathead, or the most common engine of choice: the venerable Chevy small-block, simply by the audible tone the truck emits. Of course, varieties of small-block engines will have similar notes, but more importantly, varieties in engine "composition" will offer different levels of sound. In other words, two similar 350s with the same exhaust systems can easily transmit sounds that are completely different, and obviously that has a lot to do with cam/valvetrain combinations. But, it goes without saying the same said engines with different exhaust systems will transmit completely different sounds too, and that's what I'm here to talk about.

If you're building a particular style of pickup (nostalgic, hot rod, or contemporary), you want it to sound appropriate, right? Well, that's easier said than done. Most often, your local muffler shop is experienced enough to steer you in the right direction when it comes to pipe size, muffler choice, and muffler location. Sometimes they're not, and I've seen--scratch that, heard--numerous ill-sounding systems, not to mention poorly crafted ones. So, just what does it take to get the different exhaust notes? Let's find out.

Mufflers were created for one purpose and one purpose only: to quiet down an engine. While backpressure is sometimes an issue, it was never considered by any of the auto manufacturers. Actually, backpressure, though not totally necessary, really only comes into play with big-lift cams and higher compression engines (controlling airflow properly so as to not let unburnt gas escape the cylinder and/or let exhaust gas build up). For the average engine, it's not an issue. What is an issue is how that fuel and air mixture sounds once it has gone through its combustion cycle and is escaping the system. More often than not, your "uncorked" exhaust will sound raspy, almost annoying. On the other hand, a standard-edition Turbo-style muffler may not offer enough sound. So, your quest is to find a happy medium.

Well, there are a handful of companies out there that have already done the hard work for you. One of them, Flowmaster, has gone out of its way to not only provide, but develop an entire line of mufflers catering to everybody from the average weekend warrior to the full-on hardcore racers--providing each with the unique sound (and performance) they desire. While different muffler companies have different methods of making their mufflers work, Flowmaster has developed a patented technology to provide that unmistakable Flowmaster sound. Called Delta Flow Technology, they are able to fine-tune each muffler with a series of multiple deflectors. In past years, mufflers were constructed with single deflectors (many other brands still are), but, according to Flowmaster, "thanks to state-of-the-art electronic sensing, Flowmaster can now produce mufflers with internal elements placed at tolerances of +/- .004-inch, twice the standard required by OEM car manufacturers. It is this exact placement of components within the muffler that makes Delta Flow Technology possible." They also compare this technology to the likes of tuning an instrument: "If you've ever played a musical instrument, you understand how slight the differences are between being in-tune and being out-of-tune. Only sophisticated electronic sensing devices can place the deflectors with the accuracy required." In other words, a Flowmaster isn't simply an ordinary muffler with a red and black logo plastered on it. As great as it sounds, though, not all Flowmasters are equipped with Delta Flow Technology, but that's not really a bad thing. . .read on.

Not too long ago, Flowmaster "reversed" its technology and introduced its version of the classic glasspack, which they've dubbed the Hushpower II. Obviously not your average old-school muffler in composition, it is compact like the glass and steelpacks from eras past, which is great for anyone with a tight-quartered chassis. Sound-wise, there is no comparison. The Hushpowers are enclosed in a trademarked Cool Shell casing, which contributes to both sound and heat control. Layered-laminar internals use guided sound control for a mellower tone than most typical Flowmasters.

We found ourselves in a bit of a quandary with muffler choice (which, as you can probably guess, spawned this here little article!) just recently. We had installed a set of 2 1/2-inch Hushpower IIs in a pickup with a very broken-in Chevy 350 equipped with full-length headers. The sound was very welcomed: somewhat glasspackish, but with a distinctive yet aggressive tone for its size. Shortly thereafter, the worn-out 350 was replaced with a stroker 383. Well, our welcomed sound was not quite as welcomed as before. The freshness accompanied by the cylinder head configuration of the new engine made it seem like we were running a completely different exhaust system--and in theory, we pretty much were. The aggressiveness became overwhelming, especially at higher RPMs (basically, it sounded more like a '64 Impala with hydraulics should). A call to Flowmaster helped solve the solution: They suggested swapping the Hushpowers for a set of 2 1/2-inch Super 40s. Once we had our new mufflers in hand, we headed down to our local muffler shop to make a few changes.

De Anza Muffler was happy to oblige (for obvious reasons!), and, along with swapping out our mufflers, ended up terminating the exhaust just up over the rearend housing rather than all the way out past the tailgate. The end result? A more pleasing sound and, better yet, a sound more fitting of the truck it's being emitted by. Don't get us wrong; the Hushpowers are by no means an inferior muffler. No, this was just a case of having chosen the wrong muffler for a particular application, which goes right back to the whole basis of the story and choosing the right muffler to give your truck its proper identity.

Now, while you can't hear the differences the two mufflers make (on the same truck) here on the site, we brought along a digital video camera to capture the audibles along with the visuals.

Giving your truck the character it deserves goes beyond wheel choice and color schemes. No, character has a lot to do with the way your truck sounds, and we're not talking about creaking from worn-out suspension! Flowmaster can give your truck that old-school rap (with a twist!) with its line of Hushpower II mufflers, or that flex of muscle with its Super 40s.