Exhaustive Series #3: Exhaust Configuration & Materials
You know the parts; you've seen the systems. Let's put 'em all together.
The final leg of the journey: now that you're educated about exhaust systems, you need to know how you want to configure your new system and what materials are best for your truck. We'll put it all together in this final article.
The Sounds that Take you Back
Your motive for going down this journey with me and upgrading your exhaust may be different than my own. Maybe you're a power guy and you want that maximum horsepower to add a little get-up-n-go to your already sweet ride. Maybe your a competitive truck pull guy and need to maximize your torque to win that next big trophy. Or maybe your like me and you're chasing a dream--a memory, if you will--of a sound, a vibrating, masculine powerful growl. For me, I was five when I first heard it. My dad was starting up his old Harley out in the garage. The noise blew me away. When he let me go for a ride with him, I knew right then I'd have to have one of these when I grow up. There's something primal about the exhaust rumble coming from a dragster or pickup truck. At least there used to be. Today's stock exhaust systems are designed to reign in that beast, and we, here at Midwest Aftermarket, want to help you unleash it. We'll cover all the various configurations and material questions in this article, plus wrap up with some talk about what you need to get that sound you crave. We've already told you that if you want max power gains, the complete overhaul is the best way to go if money is no option. We've discussed more economic options to get the best for your buck. But the resonance that calls you back--that animal exhaust noise that speaks of the life of your truck--we haven't forgotten that. We've just saved the best (at least in my humble opinion) for last.
Bigger is Almost Always Better... to a Point
So I know I've been going on for a while now about the improvements to horsepower and torque you can score by upgrading your exhaust system. And I know I've also stated that part of the reason why you have so much performance to gain is that those damn stock pipes tend to be a little too small, so one of the top reasons to upgrade is due to that small pipe diameter. However, you know me. Good ol' honest Abe--can't tell a lie. So whereas some manufacturers and even enthusiast, even some aftermarket parts guides, may recommend that when it comes to exhaust pipe diameter, bigger is always better, I'm here to tell you that's only half true. Since the smaller pipe does cause backpressure and restrict flow, chances are you will be upgrading to a larger pipe than what came stock with your vehicle. However, that doesn't mean you should just order the biggest freakin' pipe you can find. There are limits here--a sweet spot, if you will. While the biggest 6" diameter pipe will indeed offer the least restriction, it turns out there is another aspect that we are trying to optimize here--scavenging. I first mentioned this in the first Exhaustive Series article, but let me go a bit more in depth here. Scavenging is when the exhaust fumes from your engine get moving at the right speed and density within your pipes to create a mini-vacuum that then pulls the exhaust fumes from the next cylinders. This increases performance and horsepower as it actually aids the engine by allowing more clean air to be pulled into the cylinder. Its a win-win. But scavenging only happens when there's the right amount of gaseous fumes to fill the volume of the pipe, causing this vacuum effect. Therefore, if your pipe is too big, you lose out on this performance improving aspect of an aftermarket exhaust. So be cautious about what you hear. Bigger is better only to a point. You have to find that optimal size for your vehicle, & it all has to do with your horsepower to pipe ratio.
Piping Hot: the Truth about Exhaust Diameter
So your pipes need to hit that sweet zone (or hot zone) if you truly want to maximize your performance. Just looking for sound? Skip down some in the article. But if you want to help your engine breathe by reducing restriction and increasing scavenging, here's a handy chart. I have taken data from a number of sources and used this science stuff to give you some handy general examples so you know for real which size is right for you. Again, if you don't know your exact Horsepower, then you might start with your stock HP which you can find on your manufacturers website and then adjust for any modifications you've made by adding in the appropriate number. I'll include some common Horsepower Gains also as these may help you find your sweet spot. To truly calculate your horsepower to a near exact measure though you'll need to know what your motor's rated RPMs are and its torque. Here's a great source for calculating your horsepower: Groschopp's STP Calculator. I know that may be a lot of work so let us give you an estimate. You'll see from the chart here that unless your estimated horsepower is way off, you'll likely be able to get the optimized Downpipe size for your vehicle. But by all means, if your into calculations, give that calculator a shot and figure out exactly what your modded ride can crank out. At the very least you'll be able to brag to your friends and also order the right exhaust system to get even more of a gain. Speaking of depending on whether you've done a full Header-Back overhaul or if you just do a Cat-back, you could gain anywhere from 20 to 60 horsepower. In our chart, use the Single Exhaust column unless your system is dual all the way from the Headers on back. If you have a Y-Pipe after your Cat that ends in a dual exit exhaust or a split exhaust, that still counts as a Single exhaust for our chart since it comes off your manifolds into one pipe. Also, all examples are stock, lowest engine size from the model line for 2017 unless listed otherwise. Of course, if you've added anything it will vary. I've modified and updated my equation by starting with this guy's formula. Credit where credit is due, nerds! Here's some common Horsepower added modifications that you may have and an estimate as to how much Hp to add to your stock rating for the chart; exhausts first cause duh: Just Headers-- 20-30 Hp, Header-Back--15-20, Cat-Back--5-10; Aftermarket Cat--10-20; Performance Tuner--10-50; Large Diameter Throttle Body--25; Turbo Charger--25-60% gain. With that Turbo (first your mileage may vary), take a number between 1.25 and 1.6 and multiple your stock Horsepower to get a very rough estimate. Either way, you most likely don't need a 6 inch pipe unless you are heavily modded and started in the 400's.
Dual Vs. Single Exhaust Configurations
Defined and Compared
Your vehicle likely comes standard with a single exhaust configuration, meaning there is one exhaust downpipe with one muffler and one exhaust tip. A dual exhaust system means you have two of everything: one downpipe comes off each header and is kept separate (except for maybe an X- or H-Pipe, which we'll cover below), each side having its own Cat, Muffler, and Exhaust Tips. There are pros and cons to each. First, it should be pretty obvious that the dual exhaust allows for less restriction (but remember that diameter chart, right? So if you have the correct size piping, this may not be that big of a deal after all). Technically, all things being equal (and money and time ignored), the dual exhaust is the creme de la creme. Performance wise you are going to get more out of having a dual exhaust than a single, period. However, there's a con too. The first being the price tag. Since a dual exhaust has two of most everything, it tends to cost a bit more (sometimes twice as much). But if money isn't the limiting factor, time and effort might be. One of the pros to the single exhaust system is that it typically just replaces your stock exhaust, meaning limited install time. In fact, some single exhaust kits are mounted completely using OE hangers, meaning you shouldn't have to drill or even weld anything. Easy, peasy. Which brings me back to the dual install. Yeah, since your stock probably wasn't dual, that means you will need to do some drilling and maybe even some welding. Of course this isn't always the case, but most of the time, this is true--the dual exhaust is much more complex to install. The question is: is it worth the performance boost? Probably, if you are really looking for top of the line. If not, consider again my chart above. A properly sized single exhaust system is a great investment that you can likely install in your home garage. But that dual exhaust--might need a profession install for that one. Yet many customers long for that dual exhaust look. Which brings me to the final option: the dual-exit (single) exhaust system. You've seen these on the road whether you know it or not. In fact, many stock exhausts systems on performance cars these days come with these. This is a single exhaust system that ends in a muffler with two exhaust tips coming out of it. So if you're just looking for that dual exhaust look and sound, you can get some of it with on of these dual-exit exhaust mufflers.
Single Exhaust Systems
An aftermarket single exhaust system is similar to your stock system and may even mount in the same places.
Dual-Exit Exhaust Systems
As you can see this is really just a single exhaust system that will look like a dual to passers by at eye-level.
Dual Exhaust Systems (w/ X-Pipe)
While more work to install and a bit more pricey, Dual Exhausts are the top of the line in performance parts.
X-Pipes & H-Pipes
If you are rocking a dual exhaust (you true enthusiast, you), then you really should consider an X-Pipe or H-Pipe. Both are named as they are due to the way they look--the X looks like an "X"; the H resembles an "H." And we don't recommend them just because of their cool looks either. Both will improve your performance and reduce exhaust noise. First the reasoning: in an 8 cylinder equipped with a dual exhaust, two cylinders will fire at very similar times at a given moment on one side or bank of the engine. The exhaust is then forced through the one pipe from both cylinders at nearly the same instance. This, as you can imagine, creates backpressure. Two sources pushing fumes out at similar times means both cylinders are competing for that volume. This could create a popping noise on some models even. To get rid of that noise and release some exhaust pressure, the H & X Pipes were created. Allowing the flow of gaseous fumes from one side of the dual exhaust to the other reduces backpressure and eliminates this pop sound. However, the earlier version, the H-Pipe, would sometimes force the exhaust gas to continue straight out its side of the dual exhaust, especially at high RPMs. The newest iteration is the X-Pipe. As you can see in the provided image, the X-Pipe more thoroughly integrates both sides for that brief section, preventing this issue of momentum keeping all the fumes on one side or the other--allowing easy access to the empty space in either pipe at any given moment. Pretty ingenious. If you are concerned about the sound your engine makes at the exhaust, an X-Pipe is a must. Want to crank the most horses out and eliminate as much backpressure as humanly possible? You need one of these babies too. A common question is where to attach an X or H-Pipe into your exhaust system. Many enthusiasts suggest that you should mount them near the front, closer to your headers. However, my step-dad, a former amateur drag racer, told me that guys used to do a crayon test to figure out the best spot for an X-Pipe. They'd rub the crayon along the length of the exhaust and then drive round the track once. When they stopped and jacked the racer up, they'd find the first spot along the exhaust where the crayon hadn't melted, and they'd mount their X-pipe there. Who knows though. Could just be an old wive's--I mean, gearhead's--tale, I suppose.
From So-So to Stellar
As our exhaustive series flows to a close I'd like to share some exhaust material wisdom with ya. This last part is much less controversial nor complicated, but it is nonetheless important. After all, if I can go on and on about diameter of your pipes, you would imagine that what the pipes are made of is just as if not more important--and you'd be correct. What makes it more simple to write about and consider when purchasing is that there aren't any real calculations or opinions here--besides how much you want to spend.
Aluminized Steel (Cheapest Cost & Least Durable)
Starting with the cheapest and least durable, we have Aluminized Steel (sometimes also referred to as Polished Aluminum Stainless Steel). This steel core material is coated in aluminum alloy to prevent corrosion. And for the most part, it does a pretty good job at that. Aluminized Steel has that nice polished finish that many consumer's like. Where it falls short is in chipping. These products are prone to it, and once that aluminum coating chips off--corrosion begins. For all its shortcomings, these products are also the cheapest on the market, making them great for those just getting into aftermarket upgrades. If you don't live in an area prone to extreme weather (thinking snow storms mostly here but also extremely high humidity) and aren't planning on going off road or driving on rocky gravel roads (which might lead to more chipping), then these products may last you a long time. It isn't that aluminized steel isn't a good material. It just isn't the best. A slight step up that some manufacturers are now offering is aluminized steel with a powder coating. There are claims that this coating protects the core material longer, and I'm prone to agree. But regardless, if you are looking for true top of the line in your exhaust material, you're going to have to look elsewhere.
409 Stainless Steel (Middle of the Road)
The next step up and perhaps the most common material type currently on the market is 409 Stainless Steel. Now be careful here as many products don't explain what kind of stainless steel they are actually composed of, so educate yourself (or just look at the pics below as I'll tell ya). 409 is the minimum grade of steel formation that can be labeled stainless. Here's a problem I've always had with that term: "stainless." Have you ever had a "stainless" piece of metal (maybe a fork or knife for instance) that eventually, over time, started to rust? Doesn't sound too stainless to me. That's because this minimum grade stainless steel actually is prone to surface rust. Now it may take 5 or even 10 years for this rust to form, but rust it shall, eventually. For many consumers though this isn't that big of a deal. 5 years is a long time, and the majority of your exhaust system is not going to be visible to anyone but your mechanic when she puts your ride on a lift. So who cares really? Here's who: anyone who's going to do serious driving in the elements or in harsh climate. Again if you live somewhere with high humidity and/or high levels of snowfall you should probably not settle for anything less than the best. Furthermore, turns out that 409 stainless is more prone to rust when it is repeatedly exposed to heat. This is of course nothing to worry about because your exhaust likely never gets hot--nah, never, right?
The Magnet Test: Distinguishing 304 from 409
Should you be browsing locally or inspecting your buddy's exhaust system, you may not be able to tell the difference between 409 stainless and 304 stainless steel. Here's a nifty trick: whip out a magnet. A magnet will be attracted to 409 stainless as it is largely composed to iron (Fe) which is--you guessed it--magnetic. The large amounts of chromium and nickel in 304 will make it very unlikely to attract any magnet, except if it has been heated to extreme temperatures (such as if it had to be welded, so when checking with your magnet, make sure to avoid the welded ends). You might be able to save yourself (or your friend) from a poor purchase. Some dealers emphasize the stainless steel of their products, but upon closer inspection, you'll learn that they aren't really selling you the top of the line products they are claiming to. Educate yourself and make sure if you are paying for the best, you are also getting the best material. I conducted my own little magnet test on this random downpipe we had cluttering up the office by using one of Mob Armor's MobNetic Pro magnet Stks. Guess what? This downpipe is definitely made of 409 Stainless Steel!
304 Stainless Steel: The Top-of-the-Line
I've already alluded to it, but let's throw it out there: 304 Stainless Steel is the shiznit when it comes to exhaust material. Due in part to the low amount of iron, this stuff isn't magnetic and is much less prone to rust. Even in harsher climates, 304 is likely to last at least 10 years if not more before rusting. Do note though that if you examine an all 304 stainless exhaust system after a few years of use, you may notice that it turns a sort of gold-like color. This is perfectly natural and is not rust which will eat through your metal and ruin your exhaust. Its a simple chemical reaction (not oxidation--rust), so don't panic if your exhaust starts to look a little more golden than silver over time. This is due to heat tint or temper color. Fun with science! Nevertheless, this is the true top-of-the-line exhaust material. The downside is that 304 does cost a little extra, but the added durability will make it worth it over the years.
Manufacturer & Product Line Examples
Now for some actual examples just to show you how hard it is to distinguish one from the other (especially if you don't have a magnet handy or are browsing online only). As you can see from the images below these products when brand new are pretty hard to distinguish between based upon shine and look. Of course, if you're dealing with black powder coated aluminum stainless steel, that'll stand out pretty easy. But if it looks silvery, good luck. I've chosen some representative examples here, starting with an Aluminized Steel Exhaust from MagnaFlow, then a Banks Power 409 Stainless Steel Exhaust, and finally a Borla 304 Stainless Steel Cat-Back Exhaust. It may be hard to see the difference in quality, so I'll include the brands you'll want to shop if you are only looking for one specific material grade below. If the manufacturer only makes products using one type of steel, I'll include "(Only)" after it. And if there are specific model lines or brand names that the manufacturer uses to refer to their 304 or 409 series for instance, I'll include that also in parenthesis to help you find the product and quality you desire. If you are only looking for the best of the best and don't want to have to read the product descriptions carefully then, stick with the brands that "Only" produce Exhausts made from 304 Stainless Steel, such as Borla, Perrin, and Tanabe. If you want something else, browse around. MBRP's series names really help you to make sure you are getting what you want, for instance.
Aluminized Steel Exhausts
The following manufacturers, which we carry, all produce at least one line of aluminized steel, an economy exhaust:
aFe, Diamond Eye, Gibson, Flowmaster, MagnaFlow, MBRP (Black, Installer, PLM-, and P-Series), and Silverline.
409 Stainless Steel Exhausts
Many manufacturers have a middle of the road 409 Stainless Steel Exhaust line; here's who we carry:
aFe, Diamond Eye, Banks Power (Only), Flowmaster, MagnaFlow, MBRP (XP & SLM Series), & Silverline.
304 Stainless Steel Exhausts
A true top-of-the-line exhaust product is made from 304 Stainless Steel. The models we carry are from:
aFe, Borla (Only), Flowmaster (mufflers only), Gibson, MBRP (Pro-series), Perrin (Only), Silverline, & Tanabe (Only).
A Quick Note on Headers
And What They're Made Of
Now that you know the in's and out's of exhaust pipe material and can determine the difference between 409 and 304 stainless steel with the use of a simple magnet, here's a brief note on Headers and Header material. You likely already figured that just as there are different qualities of material for piping, there are also different qualities for your headers. You've already learned the difference between 409 and 304, and that same lesson applies here. The 304's are the top-of-the-line. Beyond core material though you also need to consider the finishes. Starting with the cheapest and least durable, we have what's commonly referred to as mild steel or nickel-chrome plated or polished. Similar to the aluminized steel already discussed, these headers are better than your stock manifold, but prone to--you guessed it--chipping and rust. Next up we have non-finished headers. These are uncoated headers made of 409 or 304 stainless steel, and just as before, the 304 is superior and less prone to corrosion over time at extreme temperatures, unlike the less durable 409. Finally, we have a new entry for a top of the line coating: ceramic. 304 steel coated in ceramic is the most durable, giving the most protection from excessive heat exposure (which you'll have with combustion engines, won't ya?) and rust. These bad boys are truly performance grade. Again, if you are going for a top-of-the-line exhaust from start to finish, you'll want 304 stainless steel ceramic coated headers. Keep in mind that just as with the pipes, you can't always see the difference. Even ceramic coating is often given a silver finish, so you'll have to do your research carefully before you buy.
Nickel-Chrome Plated (Mild Steel)
Some companies offer a more economic option in headers, such as this chrome plated model from Pace Setter. Please note that Pace Setter also offers an "Armor Coat" on these Headers which is a metallic-coating, bring them up a notch.
(Naked) 304 Stainless Steel
We only sell naked 304 Stainless Steel Headers, as to us 409 is just below par, but other companies may offer you a product that is not as superior, so read carefully. For most consumers, these products get the job done every time.
While we don't carry a lot of ceramic coated headers, these BBK Silver Ceramics show you just how similar a naked 304 and Ceramic Coated 304 can appear to the naked eye. underneath that coat these are the same as a 304 Header.
Sound: The Real Reason We are Exhaust Junkies
At Least My True Reason
Now that we have all that science stuff out of the way, let's talk the main reason most enthusiasts are adding on an aftermarket exhaust--that sweet rumble! Since stock mufflers and exhaust systems are designed to keep sound to a minimum all to the detriment of your engine due to backpressure and restriction, your vehicle isn't releasing its full potential of performance or sound until you get an aftermarket exhaust installed. These systems let your truck or Jeep breathe and that powerful exhale can really take your breath away. As for what sound you are looking for or your vehicle naturally provides, that all depends on personal preference, and you know our motto--we aren't going to judge here. If you want a deep growl. Cool. If what you're after is more of a purr. That's cool too. The sound of your engine's exhaust is the essence of your ride and the lingering after image left in bystander's ears and minds. To us, this is one of the most important and good reasons to upgrade your exhaust. Science and performance aside, your buddy holding his beer sitting on his porch down the block can't really understand the extra horses your aftermarket exhaust is putting out. But he can hear that rumble a mile away and know your coming down the drive. This sound is your vehicle's calling card--its acoustic identity. Let your ride be her natural self. Let his inner beast show. To do all that, you're going to have to select the right microphone--in this case, your muffler. Again no one can tell you what sound and hence what muffler is right for you, but the majority of the noise from your vehicle is going to be determined by that muffler, so select carefully. Here's our advise if you are a true audiophile when it comes to engine exhaust: give them a listen. Most manufacturers have audio clips of their various mufflers right on their websites and if not there, there's this fancy new site called YouTube that you might have heard of. Get on there, search the mufflers you're considering, and narrow it down to the one that feels--and sounds--right for you. Its your truck. Give it the sound you want by selecting the perfect muffler for you and your rig. Then hop on here and order the bad boy so you can start sounding off.
"Straight Through" Mufflers
Offering perhaps the most extreme and aggressive as well as the most "true" to your engine growl, these mufflers resemble tubes likely only slightly larger than your downpipe, and are sometimes referred to as glasspacks.
Split Tailpipe Mufflers
Giving you that dual exhaust look with typically a milder tone, split tailpipe mufflers allow for a range of sound that various on the manufacturer and model. If you are looking for a more nuanced purr, likely start by listening to these.
True Dual Exhaust Mufflers
For max performance and sound without the glasspack, a dual exhaust will give you the thunder you crave. These Borla ATAK's offer the maximum decibels for any street legal ride. True Dual Exhaust's make their presence known!
I know I am. Well, you did it. You survived our Exhaustive Series on all things Exhaust. Now that you have the knowledge, it's time to start your aftermarket exhaust project. Don't be intimidated. You've done the research. Now zero in on the right exhaust system for you. Maybe you've known for a while now that you want a Cat-Back system. Done and done. Or perhaps your going to do your own custom install, buying everything from Headers to the Tailpipe individually. Get on it! That's a great way to set up your exhaust in exactly the configuration you want. Maybe you just want an Axle-Back with the Muffler that lets your motor scream! We've got plenty of 'em. Whatever your exhaust needs, our inventory is inexhaustible--pun intended.
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